Merge lines.love

7 files changed, 1153 insertions, 1367 deletions

diff --git a/app.lua b/app.lua
index e717220..cf6de60 100644
--- a/app.lua
+++ b/app.lua
@@ -1,7 +1,7 @@
 -- love.run: main entrypoint function for LÖVE
 --
--- Most apps can just use the default, but we need to override it to
--- install a test harness.
+-- Most apps can just use the default shown in https://love2d.org/wiki/love.run,
+-- but we need to override it to install a test harness.
 --
 -- A test harness needs to check what the 'real' code did.
 -- To do this it needs to hook into primitive operations performed by code.
@@ -134,7 +134,11 @@ end
 
 function App.run_tests_and_initialize()
   App.load()
+  Test_errors = {}
   App.run_tests()
+  if #Test_errors > 0 then
+    error('There were test failures:\n\n'..table.concat(Test_errors))
+  end
   App.disable_tests()
   App.initialize_globals()
   App.initialize(love.arg.parseGameArguments(arg), arg)
@@ -365,15 +369,23 @@ function App.run_tests()
   table.sort(sorted_names)
   for _,name in ipairs(sorted_names) do
     App.initialize_for_test()
-    _G[name]()
+    xpcall(_G[name], function(err) prepend_debug_info_to_test_failure(name, err) end)
   end
-  print()
   -- clean up all test methods
   for _,name in ipairs(sorted_names) do
     _G[name] = nil
   end
 end
 
+-- prepend file/line/test
+function prepend_debug_info_to_test_failure(test_name, err)
+  local err_without_line_number = err:gsub('^[^:]*:[^:]*: ', '')
+  local stack_trace = debug.traceback('', --[[stack frame]]5)
+  local file_and_line_number = stack_trace:gsub('stack traceback:\n', ''):gsub(': .*', '')
+  local full_error = file_and_line_number..':'..test_name..' -- '..err_without_line_number
+  table.insert(Test_errors, full_error)
+end
+
 -- call this once all tests are run
 -- can't run any tests after this
 function App.disable_tests()
diff --git a/drawing_tests.lua b/drawing_tests.lua
index 12e9329..91c4825 100644
--- a/drawing_tests.lua
+++ b/drawing_tests.lua
@@ -3,7 +3,6 @@
 -- of specific shapes. In particular, no tests of freehand drawings.
 
 function test_creating_drawing_saves()
-  io.write('\ntest_creating_drawing_saves')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.filename = 'foo'
@@ -14,16 +13,15 @@ function test_creating_drawing_saves()
   edit.run_after_mouse_click(Editor_state, 8,Editor_state.top+8, 1)
   -- file not immediately saved
   edit.update(Editor_state, 0.01)
-  check_nil(App.filesystem['foo'], 'F - test_creating_drawing_saves/early')
+  check_nil(App.filesystem['foo'], 'early')
   -- wait until save
   Current_time = Current_time + 3.1
   edit.update(Editor_state, 0)
   -- filesystem contains drawing and an empty line of text
-  check_eq(App.filesystem['foo'], '```lines\n```\n\n', 'F - test_creating_drawing_saves')
+  check_eq(App.filesystem['foo'], '```lines\n```\n\n', 'check')
 end
 
 function test_draw_line()
-  io.write('\ntest_draw_line')
   -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
   App.screen.init{width=Test_margin_left+256, height=300}  -- drawing coordinates 1:1 with pixels
   Editor_state = edit.initialize_test_state()
@@ -32,24 +30,24 @@ function test_draw_line()
   Text.redraw_all(Editor_state)
   Editor_state.current_drawing_mode = 'line'
   edit.draw(Editor_state)
-  check_eq(#Editor_state.lines, 2, 'F - test_draw_line/baseline/#lines')
-  check_eq(Editor_state.lines[1].mode, 'drawing', 'F - test_draw_line/baseline/mode')
-  check_eq(Editor_state.line_cache[1].starty, Editor_state.top+Drawing_padding_top, 'F - test_draw_line/baseline/y')
-  check_eq(Editor_state.lines[1].h, 128, 'F - test_draw_line/baseline/y')
-  check_eq(#Editor_state.lines[1].shapes, 0, 'F - test_draw_line/baseline/#shapes')
+  check_eq(#Editor_state.lines, 2, 'baseline/#lines')
+  check_eq(Editor_state.lines[1].mode, 'drawing', 'baseline/mode')
+  check_eq(Editor_state.line_cache[1].starty, Editor_state.top+Drawing_padding_top, 'baseline/y')
+  check_eq(Editor_state.lines[1].h, 128, 'baseline/y')
+  check_eq(#Editor_state.lines[1].shapes, 0, 'baseline/#shapes')
   -- draw a line
   edit.run_after_mouse_press(Editor_state, Editor_state.left+5, Editor_state.top+Drawing_padding_top+6, 1)
   edit.run_after_mouse_release(Editor_state, Editor_state.left+35, Editor_state.top+Drawing_padding_top+36, 1)
   local drawing = Editor_state.lines[1]
-  check_eq(#drawing.shapes, 1, 'F - test_draw_line/#shapes')
-  check_eq(#drawing.points, 2, 'F - test_draw_line/#points')
-  check_eq(drawing.shapes[1].mode, 'line', 'F - test_draw_line/shape:1')
+  check_eq(#drawing.shapes, 1, '#shapes')
+  check_eq(#drawing.points, 2, '#points')
+  check_eq(drawing.shapes[1].mode, 'line', 'shape:1')
   local p1 = drawing.points[drawing.shapes[1].p1]
   local p2 = drawing.points[drawing.shapes[1].p2]
-  check_eq(p1.x, 5, 'F - test_draw_line/p1:x')
-  check_eq(p1.y, 6, 'F - test_draw_line/p1:y')
-  check_eq(p2.x, 35, 'F - test_draw_line/p2:x')
-  check_eq(p2.y, 36, 'F - test_draw_line/p2:y')
+  check_eq(p1.x, 5, 'p1:x')
+  check_eq(p1.y, 6, 'p1:y')
+  check_eq(p2.x, 35, 'p2:x')
+  check_eq(p2.y, 36, 'p2:y')
   -- wait until save
   Current_time = Current_time + 3.1
   edit.update(Editor_state, 0)
@@ -58,19 +56,18 @@ function test_draw_line()
   load_from_disk(Editor_state)
   Text.redraw_all(Editor_state)
   local drawing = Editor_state.lines[1]
-  check_eq(#drawing.shapes, 1, 'F - test_draw_line/save/#shapes')
-  check_eq(#drawing.points, 2, 'F - test_draw_line/save/#points')
-  check_eq(drawing.shapes[1].mode, 'line', 'F - test_draw_line/save/shape:1')
+  check_eq(#drawing.shapes, 1, 'save/#shapes')
+  check_eq(#drawing.points, 2, 'save/#points')
+  check_eq(drawing.shapes[1].mode, 'line', 'save/shape:1')
   local p1 = drawing.points[drawing.shapes[1].p1]
   local p2 = drawing.points[drawing.shapes[1].p2]
-  check_eq(p1.x, 5, 'F - test_draw_line/save/p1:x')
-  check_eq(p1.y, 6, 'F - test_draw_line/save/p1:y')
-  check_eq(p2.x, 35, 'F - test_draw_line/save/p2:x')
-  check_eq(p2.y, 36, 'F - test_draw_line/save/p2:y')
+  check_eq(p1.x, 5, 'save/p1:x')
+  check_eq(p1.y, 6, 'save/p1:y')
+  check_eq(p2.x, 35, 'save/p2:x')
+  check_eq(p2.y, 36, 'save/p2:y')
 end
 
 function test_draw_horizontal_line()
-  io.write('\ntest_draw_horizontal_line')
   -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
   App.screen.init{width=Test_margin_left+256, height=300}  -- drawing coordinates 1:1 with pixels
   Editor_state = edit.initialize_test_state()
@@ -78,28 +75,27 @@ function test_draw_horizontal_line()
   Text.redraw_all(Editor_state)
   Editor_state.current_drawing_mode = 'manhattan'
   edit.draw(Editor_state)
-  check_eq(#Editor_state.lines, 2, 'F - test_draw_horizontal_line/baseline/#lines')
-  check_eq(Editor_state.lines[1].mode, 'drawing', 'F - test_draw_horizontal_line/baseline/mode')
-  check_eq(Editor_state.line_cache[1].starty, Editor_state.top+Drawing_padding_top, 'F - test_draw_horizontal_line/baseline/y')
-  check_eq(Editor_state.lines[1].h, 128, 'F - test_draw_horizontal_line/baseline/y')
-  check_eq(#Editor_state.lines[1].shapes, 0, 'F - test_draw_horizontal_line/baseline/#shapes')
+  check_eq(#Editor_state.lines, 2, 'baseline/#lines')
+  check_eq(Editor_state.lines[1].mode, 'drawing', 'baseline/mode')
+  check_eq(Editor_state.line_cache[1].starty, Editor_state.top+Drawing_padding_top, 'baseline/y')
+  check_eq(Editor_state.lines[1].h, 128, 'baseline/y')
+  check_eq(#Editor_state.lines[1].shapes, 0, 'baseline/#shapes')
   -- draw a line that is more horizontal than vertical
   edit.run_after_mouse_press(Editor_state, Editor_state.left+5, Editor_state.top+Drawing_padding_top+6, 1)
   edit.run_after_mouse_release(Editor_state, Editor_state.left+35, Editor_state.top+Drawing_padding_top+26, 1)
   local drawing = Editor_state.lines[1]
-  check_eq(#drawing.shapes, 1, 'F - test_draw_horizontal_line/#shapes')
-  check_eq(#drawing.points, 2, 'F - test_draw_horizontal_line/#points')
-  check_eq(drawing.shapes[1].mode, 'manhattan', 'F - test_draw_horizontal_line/shape_mode')
+  check_eq(#drawing.shapes, 1, '#shapes')
+  check_eq(#drawing.points, 2, '#points')
+  check_eq(drawing.shapes[1].mode, 'manhattan', 'shape_mode')
   local p1 = drawing.points[drawing.shapes[1].p1]
   local p2 = drawing.points[drawing.shapes[1].p2]
-  check_eq(p1.x, 5, 'F - test_draw_horizontal_line/p1:x')
-  check_eq(p1.y, 6, 'F - test_draw_horizontal_line/p1:y')
-  check_eq(p2.x, 35, 'F - test_draw_horizontal_line/p2:x')
-  check_eq(p2.y, p1.y, 'F - test_draw_horizontal_line/p2:y')
+  check_eq(p1.x, 5, 'p1:x')
+  check_eq(p1.y, 6, 'p1:y')
+  check_eq(p2.x, 35, 'p2:x')
+  check_eq(p2.y, p1.y, 'p2:y')
 end
 
 function test_draw_circle()
-  io.write('\ntest_draw_circle')
   -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
   App.screen.init{width=Test_margin_left+256, height=300}  -- drawing coordinates 1:1 with pixels
   Editor_state = edit.initialize_test_state()
@@ -107,28 +103,27 @@ function test_draw_circle()
   Text.redraw_all(Editor_state)
   Editor_state.current_drawing_mode = 'line'
   edit.draw(Editor_state)
-  check_eq(#Editor_state.lines, 2, 'F - test_draw_circle/baseline/#lines')
-  check_eq(Editor_state.lines[1].mode, 'drawing', 'F - test_draw_circle/baseline/mode')
-  check_eq(Editor_state.line_cache[1].starty, Editor_state.top+Drawing_padding_top, 'F - test_draw_circle/baseline/y')
-  check_eq(Editor_state.lines[1].h, 128, 'F - test_draw_circle/baseline/y')
-  check_eq(#Editor_state.lines[1].shapes, 0, 'F - test_draw_circle/baseline/#shapes')
+  check_eq(#Editor_state.lines, 2, 'baseline/#lines')
+  check_eq(Editor_state.lines[1].mode, 'drawing', 'baseline/mode')
+  check_eq(Editor_state.line_cache[1].starty, Editor_state.top+Drawing_padding_top, 'baseline/y')
+  check_eq(Editor_state.lines[1].h, 128, 'baseline/y')
+  check_eq(#Editor_state.lines[1].shapes, 0, 'baseline/#shapes')
   -- draw a circle
   App.mouse_move(Editor_state.left+4, Editor_state.top+Drawing_padding_top+4)  -- hover on drawing
   edit.run_after_keychord(Editor_state, 'C-o')
   edit.run_after_mouse_press(Editor_state, Editor_state.left+35, Editor_state.top+Drawing_padding_top+36, 1)
   edit.run_after_mouse_release(Editor_state, Editor_state.left+35+30, Editor_state.top+Drawing_padding_top+36, 1)
   local drawing = Editor_state.lines[1]
-  check_eq(#drawing.shapes, 1, 'F - test_draw_circle/#shapes')
-  check_eq(#drawing.points, 1, 'F - test_draw_circle/#points')
-  check_eq(drawing.shapes[1].mode, 'circle', 'F - test_draw_horizontal_line/shape_mode')
-  check_eq(drawing.shapes[1].radius, 30, 'F - test_draw_circle/radius')
+  check_eq(#drawing.shapes, 1, '#shapes')
+  check_eq(#drawing.points, 1, '#points')
+  check_eq(drawing.shapes[1].mode, 'circle', 'shape_mode')
+  check_eq(drawing.shapes[1].radius, 30, 'radius')
   local center = drawing.points[drawing.shapes[1].center]
-  check_eq(center.x, 35, 'F - test_draw_circle/center:x')
-  check_eq(center.y, 36, 'F - test_draw_circle/center:y')
+  check_eq(center.x, 35, 'center:x')
+  check_eq(center.y, 36, 'center:y')
 end
 
 function test_cancel_stroke()
-  io.write('\ntest_cancel_stroke')
   -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
   App.screen.init{width=Test_margin_left+256, height=300}  -- drawing coordinates 1:1 with pixels
   Editor_state = edit.initialize_test_state()
@@ -137,22 +132,21 @@ function test_cancel_stroke()
   Text.redraw_all(Editor_state)
   Editor_state.current_drawing_mode = 'line'
   edit.draw(Editor_state)
-  check_eq(#Editor_state.lines, 2, 'F - test_cancel_stroke/baseline/#lines')
-  check_eq(Editor_state.lines[1].mode, 'drawing', 'F - test_cancel_stroke/baseline/mode')
-  check_eq(Editor_state.line_cache[1].starty, Editor_state.top+Drawing_padding_top, 'F - test_cancel_stroke/baseline/y')
-  check_eq(Editor_state.lines[1].h, 128, 'F - test_cancel_stroke/baseline/y')
-  check_eq(#Editor_state.lines[1].shapes, 0, 'F - test_cancel_stroke/baseline/#shapes')
+  check_eq(#Editor_state.lines, 2, 'baseline/#lines')
+  check_eq(Editor_state.lines[1].mode, 'drawing', 'baseline/mode')
+  check_eq(Editor_state.line_cache[1].starty, Editor_state.top+Drawing_padding_top, 'baseline/y')
+  check_eq(Editor_state.lines[1].h, 128, 'baseline/y')
+  check_eq(#Editor_state.lines[1].shapes, 0, 'baseline/#shapes')
   -- start drawing a line
   edit.run_after_mouse_press(Editor_state, Editor_state.left+5, Editor_state.top+Drawing_padding_top+6, 1)
   -- cancel
   edit.run_after_keychord(Editor_state, 'escape')
   edit.run_after_mouse_release(Editor_state, Editor_state.left+35, Editor_state.top+Drawing_padding_top+36, 1)
   local drawing = Editor_state.lines[1]
-  check_eq(#drawing.shapes, 0, 'F - test_cancel_stroke/#shapes')
+  check_eq(#drawing.shapes, 0, '#shapes')
 end
 
 function test_keys_do_not_affect_shape_when_mouse_up()
-  io.write('\ntest_keys_do_not_affect_shape_when_mouse_up')
   -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
   App.screen.init{width=Test_margin_left+256, height=300}  -- drawing coordinates 1:1 with pixels
   Editor_state = edit.initialize_test_state()
@@ -164,12 +158,11 @@ function test_keys_do_not_affect_shape_when_mouse_up()
   App.mouse_move(Editor_state.left+4, Editor_state.top+Drawing_padding_top+4)  -- hover on drawing
   edit.run_after_keychord(Editor_state, 'o')
   -- no change to drawing mode
-  check_eq(Editor_state.current_drawing_mode, 'line', 'F - test_keys_do_not_affect_shape_when_mouse_up/drawing_mode')
+  check_eq(Editor_state.current_drawing_mode, 'line', 'drawing_mode')
   -- no change to text either because we didn't run the text_input event
 end
 
 function test_draw_circle_mid_stroke()
-  io.write('\ntest_draw_circle_mid_stroke')
   -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
   App.screen.init{width=Test_margin_left+256, height=300}  -- drawing coordinates 1:1 with pixels
   Editor_state = edit.initialize_test_state()
@@ -177,28 +170,27 @@ function test_draw_circle_mid_stroke()
   Text.redraw_all(Editor_state)
   Editor_state.current_drawing_mode = 'line'
   edit.draw(Editor_state)
-  check_eq(#Editor_state.lines, 2, 'F - test_draw_circle_mid_stroke/baseline/#lines')
-  check_eq(Editor_state.lines[1].mode, 'drawing', 'F - test_draw_circle_mid_stroke/baseline/mode')
-  check_eq(Editor_state.line_cache[1].starty, Editor_state.top+Drawing_padding_top, 'F - test_draw_circle_mid_stroke/baseline/y')
-  check_eq(Editor_state.lines[1].h, 128, 'F - test_draw_circle_mid_stroke/baseline/y')
-  check_eq(#Editor_state.lines[1].shapes, 0, 'F - test_draw_circle_mid_stroke/baseline/#shapes')
+  check_eq(#Editor_state.lines, 2, 'baseline/#lines')
+  check_eq(Editor_state.lines[1].mode, 'drawing', 'baseline/mode')
+  check_eq(Editor_state.line_cache[1].starty, Editor_state.top+Drawing_padding_top, 'baseline/y')
+  check_eq(Editor_state.lines[1].h, 128, 'baseline/y')
+  check_eq(#Editor_state.lines[1].shapes, 0, 'baseline/#shapes')
   -- draw a circle
   App.mouse_move(Editor_state.left+4, Editor_state.top+Drawing_padding_top+4)  -- hover on drawing
   edit.run_after_mouse_press(Editor_state, Editor_state.left+35, Editor_state.top+Drawing_padding_top+36, 1)
   edit.run_after_text_input(Editor_state, 'o')
   edit.run_after_mouse_release(Editor_state, Editor_state.left+35+30, Editor_state.top+Drawing_padding_top+36, 1)
   local drawing = Editor_state.lines[1]
-  check_eq(#drawing.shapes, 1, 'F - test_draw_circle_mid_stroke/#shapes')
-  check_eq(#drawing.points, 1, 'F - test_draw_circle_mid_stroke/#points')
-  check_eq(drawing.shapes[1].mode, 'circle', 'F - test_draw_horizontal_line/shape_mode')
-  check_eq(drawing.shapes[1].radius, 30, 'F - test_draw_circle_mid_stroke/radius')
+  check_eq(#drawing.shapes, 1, '#shapes')
+  check_eq(#drawing.points, 1, '#points')
+  check_eq(drawing.shapes[1].mode, 'circle', 'shape_mode')
+  check_eq(drawing.shapes[1].radius, 30, 'radius')
   local center = drawing.points[drawing.shapes[1].center]
-  check_eq(center.x, 35, 'F - test_draw_circle_mid_stroke/center:x')
-  check_eq(center.y, 36, 'F - test_draw_circle_mid_stroke/center:y')
+  check_eq(center.x, 35, 'center:x')
+  check_eq(center.y, 36, 'center:y')
 end
 
 function test_draw_arc()
-  io.write('\ntest_draw_arc')
   -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
   App.screen.init{width=Test_margin_left+256, height=300}  -- drawing coordinates 1:1 with pixels
   Editor_state = edit.initialize_test_state()
@@ -206,43 +198,42 @@ function test_draw_arc()
   Text.redraw_all(Editor_state)
   Editor_state.current_drawing_mode = 'circle'
   edit.draw(Editor_state)
-  check_eq(#Editor_state.lines, 2, 'F - test_draw_arc/baseline/#lines')
-  check_eq(Editor_state.lines[1].mode, 'drawing', 'F - test_draw_arc/baseline/mode')
-  check_eq(Editor_state.line_cache[1].starty, Editor_state.top+Drawing_padding_top, 'F - test_draw_arc/baseline/y')
-  check_eq(Editor_state.lines[1].h, 128, 'F - test_draw_arc/baseline/y')
-  check_eq(#Editor_state.lines[1].shapes, 0, 'F - test_draw_arc/baseline/#shapes')
+  check_eq(#Editor_state.lines, 2, 'baseline/#lines')
+  check_eq(Editor_state.lines[1].mode, 'drawing', 'baseline/mode')
+  check_eq(Editor_state.line_cache[1].starty, Editor_state.top+Drawing_padding_top, 'baseline/y')
+  check_eq(Editor_state.lines[1].h, 128, 'baseline/y')
+  check_eq(#Editor_state.lines[1].shapes, 0, 'baseline/#shapes')
   -- draw an arc
   edit.run_after_mouse_press(Editor_state, Editor_state.left+35, Editor_state.top+Drawing_padding_top+36, 1)
   App.mouse_move(Editor_state.left+35+30, Editor_state.top+Drawing_padding_top+36)
   edit.run_after_text_input(Editor_state, 'a')  -- arc mode
   edit.run_after_mouse_release(Editor_state, Editor_state.left+35+50, Editor_state.top+Drawing_padding_top+36+50, 1)  -- 45°
   local drawing = Editor_state.lines[1]
-  check_eq(#drawing.shapes, 1, 'F - test_draw_arc/#shapes')
-  check_eq(#drawing.points, 1, 'F - test_draw_arc/#points')
-  check_eq(drawing.shapes[1].mode, 'arc', 'F - test_draw_horizontal_line/shape_mode')
+  check_eq(#drawing.shapes, 1, '#shapes')
+  check_eq(#drawing.points, 1, '#points')
+  check_eq(drawing.shapes[1].mode, 'arc', 'shape_mode')
   local arc = drawing.shapes[1]
-  check_eq(arc.radius, 30, 'F - test_draw_arc/radius')
+  check_eq(arc.radius, 30, 'radius')
   local center = drawing.points[arc.center]
-  check_eq(center.x, 35, 'F - test_draw_arc/center:x')
-  check_eq(center.y, 36, 'F - test_draw_arc/center:y')
-  check_eq(arc.start_angle, 0, 'F - test_draw_arc/start:angle')
-  check_eq(arc.end_angle, math.pi/4, 'F - test_draw_arc/end:angle')
+  check_eq(center.x, 35, 'center:x')
+  check_eq(center.y, 36, 'center:y')
+  check_eq(arc.start_angle, 0, 'start:angle')
+  check_eq(arc.end_angle, math.pi/4, 'end:angle')
 end
 
 function test_draw_polygon()
-  io.write('\ntest_draw_polygon')
   -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
   App.screen.init{width=Test_margin_left+256, height=300}  -- drawing coordinates 1:1 with pixels
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'```lines', '```', ''}
   Text.redraw_all(Editor_state)
   edit.draw(Editor_state)
-  check_eq(Editor_state.current_drawing_mode, 'line', 'F - test_draw_polygon/baseline/drawing_mode')
-  check_eq(#Editor_state.lines, 2, 'F - test_draw_polygon/baseline/#lines')
-  check_eq(Editor_state.lines[1].mode, 'drawing', 'F - test_draw_polygon/baseline/mode')
-  check_eq(Editor_state.line_cache[1].starty, Editor_state.top+Drawing_padding_top, 'F - test_draw_polygon/baseline/y')
-  check_eq(Editor_state.lines[1].h, 128, 'F - test_draw_polygon/baseline/y')
-  check_eq(#Editor_state.lines[1].shapes, 0, 'F - test_draw_polygon/baseline/#shapes')
+  check_eq(Editor_state.current_drawing_mode, 'line', 'baseline/drawing_mode')
+  check_eq(#Editor_state.lines, 2, 'baseline/#lines')
+  check_eq(Editor_state.lines[1].mode, 'drawing', 'baseline/mode')
+  check_eq(Editor_state.line_cache[1].starty, Editor_state.top+Drawing_padding_top, 'baseline/y')
+  check_eq(Editor_state.lines[1].h, 128, 'baseline/y')
+  check_eq(#Editor_state.lines[1].shapes, 0, 'baseline/#shapes')
   -- first point
   edit.run_after_mouse_press(Editor_state, Editor_state.left+5, Editor_state.top+Drawing_padding_top+6, 1)
   edit.run_after_text_input(Editor_state, 'g')  -- polygon mode
@@ -252,36 +243,35 @@ function test_draw_polygon()
   -- final point
   edit.run_after_mouse_release(Editor_state, Editor_state.left+35, Editor_state.top+Drawing_padding_top+26, 1)
   local drawing = Editor_state.lines[1]
-  check_eq(#drawing.shapes, 1, 'F - test_draw_polygon/#shapes')
-  check_eq(#drawing.points, 3, 'F - test_draw_polygon/vertices')
+  check_eq(#drawing.shapes, 1, '#shapes')
+  check_eq(#drawing.points, 3, 'vertices')
   local shape = drawing.shapes[1]
-  check_eq(shape.mode, 'polygon', 'F - test_draw_polygon/shape_mode')
-  check_eq(#shape.vertices, 3, 'F - test_draw_polygon/vertices')
+  check_eq(shape.mode, 'polygon', 'shape_mode')
+  check_eq(#shape.vertices, 3, 'vertices')
   local p = drawing.points[shape.vertices[1]]
-  check_eq(p.x, 5, 'F - test_draw_polygon/p1:x')
-  check_eq(p.y, 6, 'F - test_draw_polygon/p1:y')
+  check_eq(p.x, 5, 'p1:x')
+  check_eq(p.y, 6, 'p1:y')
   local p = drawing.points[shape.vertices[2]]
-  check_eq(p.x, 65, 'F - test_draw_polygon/p2:x')
-  check_eq(p.y, 36, 'F - test_draw_polygon/p2:y')
+  check_eq(p.x, 65, 'p2:x')
+  check_eq(p.y, 36, 'p2:y')
   local p = drawing.points[shape.vertices[3]]
-  check_eq(p.x, 35, 'F - test_draw_polygon/p3:x')
-  check_eq(p.y, 26, 'F - test_draw_polygon/p3:y')
+  check_eq(p.x, 35, 'p3:x')
+  check_eq(p.y, 26, 'p3:y')
 end
 
 function test_draw_rectangle()
-  io.write('\ntest_draw_rectangle')
   -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
   App.screen.init{width=Test_margin_left+256, height=300}  -- drawing coordinates 1:1 with pixels
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'```lines', '```', ''}
   Text.redraw_all(Editor_state)
   edit.draw(Editor_state)
-  check_eq(Editor_state.current_drawing_mode, 'line', 'F - test_draw_rectangle/baseline/drawing_mode')
-  check_eq(#Editor_state.lines, 2, 'F - test_draw_rectangle/baseline/#lines')
-  check_eq(Editor_state.lines[1].mode, 'drawing', 'F - test_draw_rectangle/baseline/mode')
-  check_eq(Editor_state.line_cache[1].starty, Editor_state.top+Drawing_padding_top, 'F - test_draw_rectangle/baseline/y')
-  check_eq(Editor_state.lines[1].h, 128, 'F - test_draw_rectangle/baseline/y')
-  check_eq(#Editor_state.lines[1].shapes, 0, 'F - test_draw_rectangle/baseline/#shapes')
+  check_eq(Editor_state.current_drawing_mode, 'line', 'baseline/drawing_mode')
+  check_eq(#Editor_state.lines, 2, 'baseline/#lines')
+  check_eq(Editor_state.lines[1].mode, 'drawing', 'baseline/mode')
+  check_eq(Editor_state.line_cache[1].starty, Editor_state.top+Drawing_padding_top, 'baseline/y')
+  check_eq(Editor_state.lines[1].h, 128, 'baseline/y')
+  check_eq(#Editor_state.lines[1].shapes, 0, 'baseline/#shapes')
   -- first point
   edit.run_after_mouse_press(Editor_state, Editor_state.left+35, Editor_state.top+Drawing_padding_top+36, 1)
   edit.run_after_text_input(Editor_state, 'r')  -- rectangle mode
@@ -294,39 +284,38 @@ function test_draw_rectangle()
   -- release (decides 'thickness' of rectangle perpendicular to first edge)
   edit.run_after_mouse_release(Editor_state, Editor_state.left+15, Editor_state.top+Drawing_padding_top+26, 1)
   local drawing = Editor_state.lines[1]
-  check_eq(#drawing.shapes, 1, 'F - test_draw_rectangle/#shapes')
-  check_eq(#drawing.points, 5, 'F - test_draw_rectangle/#points')  -- currently includes every point added
+  check_eq(#drawing.shapes, 1, '#shapes')
+  check_eq(#drawing.points, 5, '#points')  -- currently includes every point added
   local shape = drawing.shapes[1]
-  check_eq(shape.mode, 'rectangle', 'F - test_draw_rectangle/shape_mode')
-  check_eq(#shape.vertices, 4, 'F - test_draw_rectangle/vertices')
+  check_eq(shape.mode, 'rectangle', 'shape_mode')
+  check_eq(#shape.vertices, 4, 'vertices')
   local p = drawing.points[shape.vertices[1]]
-  check_eq(p.x, 35, 'F - test_draw_rectangle/p1:x')
-  check_eq(p.y, 36, 'F - test_draw_rectangle/p1:y')
+  check_eq(p.x, 35, 'p1:x')
+  check_eq(p.y, 36, 'p1:y')
   local p = drawing.points[shape.vertices[2]]
-  check_eq(p.x, 75, 'F - test_draw_rectangle/p2:x')
-  check_eq(p.y, 76, 'F - test_draw_rectangle/p2:y')
+  check_eq(p.x, 75, 'p2:x')
+  check_eq(p.y, 76, 'p2:y')
   local p = drawing.points[shape.vertices[3]]
-  check_eq(p.x, 70, 'F - test_draw_rectangle/p3:x')
-  check_eq(p.y, 81, 'F - test_draw_rectangle/p3:y')
+  check_eq(p.x, 70, 'p3:x')
+  check_eq(p.y, 81, 'p3:y')
   local p = drawing.points[shape.vertices[4]]
-  check_eq(p.x, 30, 'F - test_draw_rectangle/p4:x')
-  check_eq(p.y, 41, 'F - test_draw_rectangle/p4:y')
+  check_eq(p.x, 30, 'p4:x')
+  check_eq(p.y, 41, 'p4:y')
 end
 
 function test_draw_rectangle_intermediate()
-  io.write('\ntest_draw_rectangle_intermediate')
   -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
   App.screen.init{width=Test_margin_left+256, height=300}  -- drawing coordinates 1:1 with pixels
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'```lines', '```', ''}
   Text.redraw_all(Editor_state)
   edit.draw(Editor_state)
-  check_eq(Editor_state.current_drawing_mode, 'line', 'F - test_draw_rectangle_intermediate/baseline/drawing_mode')
-  check_eq(#Editor_state.lines, 2, 'F - test_draw_rectangle_intermediate/baseline/#lines')
-  check_eq(Editor_state.lines[1].mode, 'drawing', 'F - test_draw_rectangle_intermediate/baseline/mode')
-  check_eq(Editor_state.line_cache[1].starty, Editor_state.top+Drawing_padding_top, 'F - test_draw_rectangle_intermediate/baseline/y')
-  check_eq(Editor_state.lines[1].h, 128, 'F - test_draw_rectangle_intermediate/baseline/y')
-  check_eq(#Editor_state.lines[1].shapes, 0, 'F - test_draw_rectangle_intermediate/baseline/#shapes')
+  check_eq(Editor_state.current_drawing_mode, 'line', 'baseline/drawing_mode')
+  check_eq(#Editor_state.lines, 2, 'baseline/#lines')
+  check_eq(Editor_state.lines[1].mode, 'drawing', 'baseline/mode')
+  check_eq(Editor_state.line_cache[1].starty, Editor_state.top+Drawing_padding_top, 'baseline/y')
+  check_eq(Editor_state.lines[1].h, 128, 'baseline/y')
+  check_eq(#Editor_state.lines[1].shapes, 0, 'baseline/#shapes')
   -- first point
   edit.run_after_mouse_press(Editor_state, Editor_state.left+35, Editor_state.top+Drawing_padding_top+36, 1)
   edit.run_after_text_input(Editor_state, 'r')  -- rectangle mode
@@ -337,33 +326,32 @@ function test_draw_rectangle_intermediate()
   App.mouse_move(Editor_state.left+75, Editor_state.top+Drawing_padding_top+76)
   edit.run_after_text_input(Editor_state, 'p')
   local drawing = Editor_state.lines[1]
-  check_eq(#drawing.points, 3, 'F - test_draw_rectangle_intermediate/#points')  -- currently includes every point added
+  check_eq(#drawing.points, 3, '#points')  -- currently includes every point added
   local pending = drawing.pending
-  check_eq(pending.mode, 'rectangle', 'F - test_draw_rectangle_intermediate/shape_mode')
-  check_eq(#pending.vertices, 2, 'F - test_draw_rectangle_intermediate/vertices')
+  check_eq(pending.mode, 'rectangle', 'shape_mode')
+  check_eq(#pending.vertices, 2, 'vertices')
   local p = drawing.points[pending.vertices[1]]
-  check_eq(p.x, 35, 'F - test_draw_rectangle_intermediate/p1:x')
-  check_eq(p.y, 36, 'F - test_draw_rectangle_intermediate/p1:y')
+  check_eq(p.x, 35, 'p1:x')
+  check_eq(p.y, 36, 'p1:y')
   local p = drawing.points[pending.vertices[2]]
-  check_eq(p.x, 75, 'F - test_draw_rectangle_intermediate/p2:x')
-  check_eq(p.y, 76, 'F - test_draw_rectangle_intermediate/p2:y')
+  check_eq(p.x, 75, 'p2:x')
+  check_eq(p.y, 76, 'p2:y')
   -- outline of rectangle is drawn based on where the mouse is, but we can't check that so far
 end
 
 function test_draw_square()
-  io.write('\ntest_draw_square')
   -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
   App.screen.init{width=Test_margin_left+256, height=300}  -- drawing coordinates 1:1 with pixels
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'```lines', '```', ''}
   Text.redraw_all(Editor_state)
   edit.draw(Editor_state)
-  check_eq(Editor_state.current_drawing_mode, 'line', 'F - test_draw_square/baseline/drawing_mode')
-  check_eq(#Editor_state.lines, 2, 'F - test_draw_square/baseline/#lines')
-  check_eq(Editor_state.lines[1].mode, 'drawing', 'F - test_draw_square/baseline/mode')
-  check_eq(Editor_state.line_cache[1].starty, Editor_state.top+Drawing_padding_top, 'F - test_draw_square/baseline/y')
-  check_eq(Editor_state.lines[1].h, 128, 'F - test_draw_square/baseline/y')
-  check_eq(#Editor_state.lines[1].shapes, 0, 'F - test_draw_square/baseline/#shapes')
+  check_eq(Editor_state.current_drawing_mode, 'line', 'baseline/drawing_mode')
+  check_eq(#Editor_state.lines, 2, 'baseline/#lines')
+  check_eq(Editor_state.lines[1].mode, 'drawing', 'baseline/mode')
+  check_eq(Editor_state.line_cache[1].starty, Editor_state.top+Drawing_padding_top, 'baseline/y')
+  check_eq(Editor_state.lines[1].h, 128, 'baseline/y')
+  check_eq(#Editor_state.lines[1].shapes, 0, 'baseline/#shapes')
   -- first point
   edit.run_after_mouse_press(Editor_state, Editor_state.left+35, Editor_state.top+Drawing_padding_top+36, 1)
   edit.run_after_text_input(Editor_state, 's')  -- square mode
@@ -376,26 +364,25 @@ function test_draw_square()
   -- release (decides which side of first edge to draw square on)
   edit.run_after_mouse_release(Editor_state, Editor_state.left+15, Editor_state.top+Drawing_padding_top+26, 1)
   local drawing = Editor_state.lines[1]
-  check_eq(#drawing.shapes, 1, 'F - test_draw_square/#shapes')
-  check_eq(#drawing.points, 5, 'F - test_draw_square/#points')  -- currently includes every point added
-  check_eq(drawing.shapes[1].mode, 'square', 'F - test_draw_square/shape_mode')
-  check_eq(#drawing.shapes[1].vertices, 4, 'F - test_draw_square/vertices')
+  check_eq(#drawing.shapes, 1, '#shapes')
+  check_eq(#drawing.points, 5, '#points')  -- currently includes every point added
+  check_eq(drawing.shapes[1].mode, 'square', 'shape_mode')
+  check_eq(#drawing.shapes[1].vertices, 4, 'vertices')
   local p = drawing.points[drawing.shapes[1].vertices[1]]
-  check_eq(p.x, 35, 'F - test_draw_square/p1:x')
-  check_eq(p.y, 36, 'F - test_draw_square/p1:y')
+  check_eq(p.x, 35, 'p1:x')
+  check_eq(p.y, 36, 'p1:y')
   local p = drawing.points[drawing.shapes[1].vertices[2]]
-  check_eq(p.x, 65, 'F - test_draw_square/p2:x')
-  check_eq(p.y, 66, 'F - test_draw_square/p2:y')
+  check_eq(p.x, 65, 'p2:x')
+  check_eq(p.y, 66, 'p2:y')
   local p = drawing.points[drawing.shapes[1].vertices[3]]
-  check_eq(p.x, 35, 'F - test_draw_square/p3:x')
-  check_eq(p.y, 96, 'F - test_draw_square/p3:y')
+  check_eq(p.x, 35, 'p3:x')
+  check_eq(p.y, 96, 'p3:y')
   local p = drawing.points[drawing.shapes[1].vertices[4]]
-  check_eq(p.x, 5, 'F - test_draw_square/p4:x')
-  check_eq(p.y, 66, 'F - test_draw_square/p4:y')
+  check_eq(p.x, 5, 'p4:x')
+  check_eq(p.y, 66, 'p4:y')
 end
 
 function test_name_point()
-  io.write('\ntest_name_point')
   -- create a drawing with a line
   App.screen.init{width=Test_margin_left+256, height=300}  -- drawing coordinates 1:1 with pixels
   Editor_state = edit.initialize_test_state()
@@ -408,27 +395,27 @@ function test_name_point()
   edit.run_after_mouse_press(Editor_state, Editor_state.left+5, Editor_state.top+Drawing_padding_top+6, 1)
   edit.run_after_mouse_release(Editor_state, Editor_state.left+35, Editor_state.top+Drawing_padding_top+36, 1)
   local drawing = Editor_state.lines[1]
-  check_eq(#drawing.shapes, 1, 'F - test_name_point/baseline/#shapes')
-  check_eq(#drawing.points, 2, 'F - test_name_point/baseline/#points')
-  check_eq(drawing.shapes[1].mode, 'line', 'F - test_name_point/baseline/shape:1')
+  check_eq(#drawing.shapes, 1, 'baseline/#shapes')
+  check_eq(#drawing.points, 2, 'baseline/#points')
+  check_eq(drawing.shapes[1].mode, 'line', 'baseline/shape:1')
   local p1 = drawing.points[drawing.shapes[1].p1]
   local p2 = drawing.points[drawing.shapes[1].p2]
-  check_eq(p1.x, 5, 'F - test_name_point/baseline/p1:x')
-  check_eq(p1.y, 6, 'F - test_name_point/baseline/p1:y')
-  check_eq(p2.x, 35, 'F - test_name_point/baseline/p2:x')
-  check_eq(p2.y, 36, 'F - test_name_point/baseline/p2:y')
-  check_nil(p2.name, 'F - test_name_point/baseline/p2:name')
+  check_eq(p1.x, 5, 'baseline/p1:x')
+  check_eq(p1.y, 6, 'baseline/p1:y')
+  check_eq(p2.x, 35, 'baseline/p2:x')
+  check_eq(p2.y, 36, 'baseline/p2:y')
+  check_nil(p2.name, 'baseline/p2:name')
   -- enter 'name' mode without moving the mouse
   edit.run_after_keychord(Editor_state, 'C-n')
-  check_eq(Editor_state.current_drawing_mode, 'name', 'F - test_name_point/mode:1')
+  check_eq(Editor_state.current_drawing_mode, 'name', 'mode:1')
   edit.run_after_text_input(Editor_state, 'A')
-  check_eq(p2.name, 'A', 'F - test_name_point')
+  check_eq(p2.name, 'A', 'check1')
   -- still in 'name' mode
-  check_eq(Editor_state.current_drawing_mode, 'name', 'F - test_name_point/mode:2')
+  check_eq(Editor_state.current_drawing_mode, 'name', 'mode:2')
   -- exit 'name' mode
   edit.run_after_keychord(Editor_state, 'return')
-  check_eq(Editor_state.current_drawing_mode, 'line', 'F - test_name_point/mode:3')
-  check_eq(p2.name, 'A', 'F - test_name_point')
+  check_eq(Editor_state.current_drawing_mode, 'line', 'mode:3')
+  check_eq(p2.name, 'A', 'check2')
   -- wait until save
   Current_time = Current_time + 3.1
   edit.update(Editor_state, 0)
@@ -436,11 +423,10 @@ function test_name_point()
   load_from_disk(Editor_state)
   Text.redraw_all(Editor_state)
   local p2 = Editor_state.lines[1].points[drawing.shapes[1].p2]
-  check_eq(p2.name, 'A', 'F - test_name_point/save')
+  check_eq(p2.name, 'A', 'save')
 end
 
 function test_move_point()
-  io.write('\ntest_move_point')
   -- create a drawing with a line
   App.screen.init{width=Test_margin_left+256, height=300}  -- drawing coordinates 1:1 with pixels
   Editor_state = edit.initialize_test_state()
@@ -452,15 +438,15 @@ function test_move_point()
   edit.run_after_mouse_press(Editor_state, Editor_state.left+5, Editor_state.top+Drawing_padding_top+6, 1)
   edit.run_after_mouse_release(Editor_state, Editor_state.left+35, Editor_state.top+Drawing_padding_top+36, 1)
   local drawing = Editor_state.lines[1]
-  check_eq(#drawing.shapes, 1, 'F - test_move_point/baseline/#shapes')
-  check_eq(#drawing.points, 2, 'F - test_move_point/baseline/#points')
-  check_eq(drawing.shapes[1].mode, 'line', 'F - test_move_point/baseline/shape:1')
+  check_eq(#drawing.shapes, 1, 'baseline/#shapes')
+  check_eq(#drawing.points, 2, 'baseline/#points')
+  check_eq(drawing.shapes[1].mode, 'line', 'baseline/shape:1')
   local p1 = drawing.points[drawing.shapes[1].p1]
   local p2 = drawing.points[drawing.shapes[1].p2]
-  check_eq(p1.x, 5, 'F - test_move_point/baseline/p1:x')
-  check_eq(p1.y, 6, 'F - test_move_point/baseline/p1:y')
-  check_eq(p2.x, 35, 'F - test_move_point/baseline/p2:x')
-  check_eq(p2.y, 36, 'F - test_move_point/baseline/p2:y')
+  check_eq(p1.x, 5, 'baseline/p1:x')
+  check_eq(p1.y, 6, 'baseline/p1:y')
+  check_eq(p2.x, 35, 'baseline/p2:x')
+  check_eq(p2.y, 36, 'baseline/p2:y')
   -- wait until save
   Current_time = Current_time + 3.1
   edit.update(Editor_state, 0)
@@ -469,25 +455,25 @@ function test_move_point()
   Text.redraw_all(Editor_state)
   local drawing = Editor_state.lines[1]
   local p2 = Editor_state.lines[1].points[drawing.shapes[1].p2]
-  check_eq(p2.x, 35, 'F - test_move_point/save/x')
-  check_eq(p2.y, 36, 'F - test_move_point/save/y')
+  check_eq(p2.x, 35, 'save/x')
+  check_eq(p2.y, 36, 'save/y')
   edit.draw(Editor_state)
   -- enter 'move' mode without moving the mouse
   edit.run_after_keychord(Editor_state, 'C-u')
-  check_eq(Editor_state.current_drawing_mode, 'move', 'F - test_move_point/mode:1')
+  check_eq(Editor_state.current_drawing_mode, 'move', 'mode:1')
   -- point is lifted
-  check_eq(drawing.pending.mode, 'move', 'F - test_move_point/mode:2')
-  check_eq(drawing.pending.target_point, p2, 'F - test_move_point/target')
+  check_eq(drawing.pending.mode, 'move', 'mode:2')
+  check_eq(drawing.pending.target_point, p2, 'target')
   -- move point
   App.mouse_move(Editor_state.left+26, Editor_state.top+Drawing_padding_top+44)
   edit.update(Editor_state, 0.05)
   local p2 = drawing.points[drawing.shapes[1].p2]
-  check_eq(p2.x, 26, 'F - test_move_point/x')
-  check_eq(p2.y, 44, 'F - test_move_point/y')
+  check_eq(p2.x, 26, 'x')
+  check_eq(p2.y, 44, 'y')
   -- exit 'move' mode
   edit.run_after_mouse_click(Editor_state, Editor_state.left+26, Editor_state.top+Drawing_padding_top+44, 1)
-  check_eq(Editor_state.current_drawing_mode, 'line', 'F - test_move_point/mode:3')
-  check_eq(drawing.pending, {}, 'F - test_move_point/pending')
+  check_eq(Editor_state.current_drawing_mode, 'line', 'mode:3')
+  check_eq(drawing.pending, {}, 'pending')
   -- wait until save
   Current_time = Current_time + 3.1
   edit.update(Editor_state, 0)
@@ -495,12 +481,11 @@ function test_move_point()
   load_from_disk(Editor_state)
   Text.redraw_all(Editor_state)
   local p2 = Editor_state.lines[1].points[drawing.shapes[1].p2]
-  check_eq(p2.x, 26, 'F - test_move_point/save/x')
-  check_eq(p2.y, 44, 'F - test_move_point/save/y')
+  check_eq(p2.x, 26, 'save/x')
+  check_eq(p2.y, 44, 'save/y')
 end
 
 function test_move_point_on_manhattan_line()
-  io.write('\ntest_move_point_on_manhattan_line')
   -- create a drawing with a manhattan line
   App.screen.init{width=Test_margin_left+256, height=300}  -- drawing coordinates 1:1 with pixels
   Editor_state = edit.initialize_test_state()
@@ -512,22 +497,21 @@ function test_move_point_on_manhattan_line()
   edit.run_after_mouse_press(Editor_state, Editor_state.left+5, Editor_state.top+Drawing_padding_top+6, 1)
   edit.run_after_mouse_release(Editor_state, Editor_state.left+35, Editor_state.top+Drawing_padding_top+46, 1)
   local drawing = Editor_state.lines[1]
-  check_eq(#drawing.shapes, 1, 'F - test_move_point_on_manhattan_line/baseline/#shapes')
-  check_eq(#drawing.points, 2, 'F - test_move_point_on_manhattan_line/baseline/#points')
-  check_eq(drawing.shapes[1].mode, 'manhattan', 'F - test_move_point_on_manhattan_line/baseline/shape:1')
+  check_eq(#drawing.shapes, 1, 'baseline/#shapes')
+  check_eq(#drawing.points, 2, 'baseline/#points')
+  check_eq(drawing.shapes[1].mode, 'manhattan', 'baseline/shape:1')
   edit.draw(Editor_state)
   -- enter 'move' mode
   edit.run_after_keychord(Editor_state, 'C-u')
-  check_eq(Editor_state.current_drawing_mode, 'move', 'F - test_move_point_on_manhattan_line/mode:1')
+  check_eq(Editor_state.current_drawing_mode, 'move', 'mode:1')
   -- move point
   App.mouse_move(Editor_state.left+26, Editor_state.top+Drawing_padding_top+44)
   edit.update(Editor_state, 0.05)
   -- line is no longer manhattan
-  check_eq(drawing.shapes[1].mode, 'line', 'F - test_move_point_on_manhattan_line/baseline/shape:1')
+  check_eq(drawing.shapes[1].mode, 'line', 'baseline/shape:1')
 end
 
 function test_delete_lines_at_point()
-  io.write('\ntest_delete_lines_at_point')
   -- create a drawing with two lines connected at a point
   App.screen.init{width=Test_margin_left+256, height=300}  -- drawing coordinates 1:1 with pixels
   Editor_state = edit.initialize_test_state()
@@ -541,25 +525,24 @@ function test_delete_lines_at_point()
   edit.run_after_mouse_press(Editor_state, Editor_state.left+35, Editor_state.top+Drawing_padding_top+36, 1)
   edit.run_after_mouse_release(Editor_state, Editor_state.left+55, Editor_state.top+Drawing_padding_top+26, 1)
   local drawing = Editor_state.lines[1]
-  check_eq(#drawing.shapes, 2, 'F - test_delete_lines_at_point/baseline/#shapes')
-  check_eq(drawing.shapes[1].mode, 'line', 'F - test_delete_lines_at_point/baseline/shape:1')
-  check_eq(drawing.shapes[2].mode, 'line', 'F - test_delete_lines_at_point/baseline/shape:2')
+  check_eq(#drawing.shapes, 2, 'baseline/#shapes')
+  check_eq(drawing.shapes[1].mode, 'line', 'baseline/shape:1')
+  check_eq(drawing.shapes[2].mode, 'line', 'baseline/shape:2')
   -- hover on the common point and delete
   App.mouse_move(Editor_state.left+35, Editor_state.top+Drawing_padding_top+36)
   edit.run_after_keychord(Editor_state, 'C-d')
-  check_eq(drawing.shapes[1].mode, 'deleted', 'F - test_delete_lines_at_point/shape:1')
-  check_eq(drawing.shapes[2].mode, 'deleted', 'F - test_delete_lines_at_point/shape:2')
+  check_eq(drawing.shapes[1].mode, 'deleted', 'shape:1')
+  check_eq(drawing.shapes[2].mode, 'deleted', 'shape:2')
   -- wait for some time
   Current_time = Current_time + 3.1
   edit.update(Editor_state, 0)
   -- deleted points disappear after file is reloaded
   load_from_disk(Editor_state)
   Text.redraw_all(Editor_state)
-  check_eq(#Editor_state.lines[1].shapes, 0, 'F - test_delete_lines_at_point/save')
+  check_eq(#Editor_state.lines[1].shapes, 0, 'save')
 end
 
 function test_delete_line_under_mouse_pointer()
-  io.write('\ntest_delete_line_under_mouse_pointer')
   -- create a drawing with two lines connected at a point
   App.screen.init{width=Test_margin_left+256, height=300}  -- drawing coordinates 1:1 with pixels
   Editor_state = edit.initialize_test_state()
@@ -572,19 +555,18 @@ function test_delete_line_under_mouse_pointer()
   edit.run_after_mouse_press(Editor_state, Editor_state.left+35, Editor_state.top+Drawing_padding_top+36, 1)
   edit.run_after_mouse_release(Editor_state, Editor_state.left+55, Editor_state.top+Drawing_padding_top+26, 1)
   local drawing = Editor_state.lines[1]
-  check_eq(#drawing.shapes, 2, 'F - test_delete_line_under_mouse_pointer/baseline/#shapes')
-  check_eq(drawing.shapes[1].mode, 'line', 'F - test_delete_line_under_mouse_pointer/baseline/shape:1')
-  check_eq(drawing.shapes[2].mode, 'line', 'F - test_delete_line_under_mouse_pointer/baseline/shape:2')
+  check_eq(#drawing.shapes, 2, 'baseline/#shapes')
+  check_eq(drawing.shapes[1].mode, 'line', 'baseline/shape:1')
+  check_eq(drawing.shapes[2].mode, 'line', 'baseline/shape:2')
   -- hover on one of the lines and delete
   App.mouse_move(Editor_state.left+25, Editor_state.top+Drawing_padding_top+26)
   edit.run_after_keychord(Editor_state, 'C-d')
   -- only that line is deleted
-  check_eq(drawing.shapes[1].mode, 'deleted', 'F - test_delete_line_under_mouse_pointer/shape:1')
-  check_eq(drawing.shapes[2].mode, 'line', 'F - test_delete_line_under_mouse_pointer/shape:2')
+  check_eq(drawing.shapes[1].mode, 'deleted', 'shape:1')
+  check_eq(drawing.shapes[2].mode, 'line', 'shape:2')
 end
 
 function test_delete_point_from_polygon()
-  io.write('\ntest_delete_point_from_polygon')
   -- create a drawing with two lines connected at a point
   App.screen.init{width=Test_margin_left+256, height=300}  -- drawing coordinates 1:1 with pixels
   Editor_state = edit.initialize_test_state()
@@ -604,19 +586,18 @@ function test_delete_point_from_polygon()
   -- fourth point
   edit.run_after_mouse_release(Editor_state, Editor_state.left+14, Editor_state.top+Drawing_padding_top+16, 1)
   local drawing = Editor_state.lines[1]
-  check_eq(#drawing.shapes, 1, 'F - test_delete_point_from_polygon/baseline/#shapes')
-  check_eq(drawing.shapes[1].mode, 'polygon', 'F - test_delete_point_from_polygon/baseline/mode')
-  check_eq(#drawing.shapes[1].vertices, 4, 'F - test_delete_point_from_polygon/baseline/vertices')
+  check_eq(#drawing.shapes, 1, 'baseline/#shapes')
+  check_eq(drawing.shapes[1].mode, 'polygon', 'baseline/mode')
+  check_eq(#drawing.shapes[1].vertices, 4, 'baseline/vertices')
   -- hover on a point and delete
   App.mouse_move(Editor_state.left+35, Editor_state.top+Drawing_padding_top+26)
   edit.run_after_keychord(Editor_state, 'C-d')
   -- just the one point is deleted
-  check_eq(drawing.shapes[1].mode, 'polygon', 'F - test_delete_point_from_polygon/shape')
-  check_eq(#drawing.shapes[1].vertices, 3, 'F - test_delete_point_from_polygon/vertices')
+  check_eq(drawing.shapes[1].mode, 'polygon', 'shape')
+  check_eq(#drawing.shapes[1].vertices, 3, 'vertices')
 end
 
 function test_delete_point_from_polygon()
-  io.write('\ntest_delete_point_from_polygon')
   -- create a drawing with two lines connected at a point
   App.screen.init{width=Test_margin_left+256, height=300}  -- drawing coordinates 1:1 with pixels
   Editor_state = edit.initialize_test_state()
@@ -633,18 +614,17 @@ function test_delete_point_from_polygon()
   -- third point
   edit.run_after_mouse_release(Editor_state, Editor_state.left+14, Editor_state.top+Drawing_padding_top+16, 1)
   local drawing = Editor_state.lines[1]
-  check_eq(#drawing.shapes, 1, 'F - test_delete_point_from_polygon/baseline/#shapes')
-  check_eq(drawing.shapes[1].mode, 'polygon', 'F - test_delete_point_from_polygon/baseline/mode')
-  check_eq(#drawing.shapes[1].vertices, 3, 'F - test_delete_point_from_polygon/baseline/vertices')
+  check_eq(#drawing.shapes, 1, 'baseline/#shapes')
+  check_eq(drawing.shapes[1].mode, 'polygon', 'baseline/mode')
+  check_eq(#drawing.shapes[1].vertices, 3, 'baseline/vertices')
   -- hover on a point and delete
   App.mouse_move(Editor_state.left+65, Editor_state.top+Drawing_padding_top+36)
   edit.run_after_keychord(Editor_state, 'C-d')
   -- there's < 3 points left, so the whole polygon is deleted
-  check_eq(drawing.shapes[1].mode, 'deleted', 'F - test_delete_point_from_polygon')
+  check_eq(drawing.shapes[1].mode, 'deleted', 'check')
 end
 
 function test_undo_name_point()
-  io.write('\ntest_undo_name_point')
   -- create a drawing with a line
   App.screen.init{width=Test_margin_left+256, height=300}  -- drawing coordinates 1:1 with pixels
   Editor_state = edit.initialize_test_state()
@@ -657,32 +637,32 @@ function test_undo_name_point()
   edit.run_after_mouse_press(Editor_state, Editor_state.left+5, Editor_state.top+Drawing_padding_top+6, 1)
   edit.run_after_mouse_release(Editor_state, Editor_state.left+35, Editor_state.top+Drawing_padding_top+36, 1)
   local drawing = Editor_state.lines[1]
-  check_eq(#drawing.shapes, 1, 'F - test_undo_name_point/baseline/#shapes')
-  check_eq(#drawing.points, 2, 'F - test_undo_name_point/baseline/#points')
-  check_eq(drawing.shapes[1].mode, 'line', 'F - test_undo_name_point/baseline/shape:1')
+  check_eq(#drawing.shapes, 1, 'baseline/#shapes')
+  check_eq(#drawing.points, 2, 'baseline/#points')
+  check_eq(drawing.shapes[1].mode, 'line', 'baseline/shape:1')
   local p1 = drawing.points[drawing.shapes[1].p1]
   local p2 = drawing.points[drawing.shapes[1].p2]
-  check_eq(p1.x, 5, 'F - test_undo_name_point/baseline/p1:x')
-  check_eq(p1.y, 6, 'F - test_undo_name_point/baseline/p1:y')
-  check_eq(p2.x, 35, 'F - test_undo_name_point/baseline/p2:x')
-  check_eq(p2.y, 36, 'F - test_undo_name_point/baseline/p2:y')
-  check_nil(p2.name, 'F - test_undo_name_point/baseline/p2:name')
-  check_eq(#Editor_state.history, 1, 'F - test_undo_name_point/baseline/history:1')
+  check_eq(p1.x, 5, 'baseline/p1:x')
+  check_eq(p1.y, 6, 'baseline/p1:y')
+  check_eq(p2.x, 35, 'baseline/p2:x')
+  check_eq(p2.y, 36, 'baseline/p2:y')
+  check_nil(p2.name, 'baseline/p2:name')
+  check_eq(#Editor_state.history, 1, 'baseline/history:1')
 --?   print('a', Editor_state.lines.current_drawing)
   -- enter 'name' mode without moving the mouse
   edit.run_after_keychord(Editor_state, 'C-n')
   edit.run_after_text_input(Editor_state, 'A')
   edit.run_after_keychord(Editor_state, 'return')
-  check_eq(p2.name, 'A', 'F - test_undo_name_point/baseline')
-  check_eq(#Editor_state.history, 3, 'F - test_undo_name_point/baseline/history:2')
-  check_eq(Editor_state.next_history, 4, 'F - test_undo_name_point/baseline/next_history')
+  check_eq(p2.name, 'A', 'baseline')
+  check_eq(#Editor_state.history, 3, 'baseline/history:2')
+  check_eq(Editor_state.next_history, 4, 'baseline/next_history')
 --?   print('b', Editor_state.lines.current_drawing)
   -- undo
   edit.run_after_keychord(Editor_state, 'C-z')
   local drawing = Editor_state.lines[1]
   local p2 = drawing.points[drawing.shapes[1].p2]
-  check_eq(Editor_state.next_history, 3, 'F - test_undo_name_point/next_history')
-  check_eq(p2.name, '', 'F - test_undo_name_point')  -- not quite what it was before, but close enough
+  check_eq(Editor_state.next_history, 3, 'next_history')
+  check_eq(p2.name, '', 'undo')  -- not quite what it was before, but close enough
   -- wait until save
   Current_time = Current_time + 3.1
   edit.update(Editor_state, 0)
@@ -690,11 +670,10 @@ function test_undo_name_point()
   load_from_disk(Editor_state)
   Text.redraw_all(Editor_state)
   local p2 = Editor_state.lines[1].points[drawing.shapes[1].p2]
-  check_eq(p2.name, '', 'F - test_undo_name_point/save')
+  check_eq(p2.name, '', 'save')
 end
 
 function test_undo_move_point()
-  io.write('\ntest_undo_move_point')
   -- create a drawing with a line
   App.screen.init{width=Test_margin_left+256, height=300}  -- drawing coordinates 1:1 with pixels
   Editor_state = edit.initialize_test_state()
@@ -706,34 +685,34 @@ function test_undo_move_point()
   edit.run_after_mouse_press(Editor_state, Editor_state.left+5, Editor_state.top+Drawing_padding_top+6, 1)
   edit.run_after_mouse_release(Editor_state, Editor_state.left+35, Editor_state.top+Drawing_padding_top+36, 1)
   local drawing = Editor_state.lines[1]
-  check_eq(#drawing.shapes, 1, 'F - test_undo_move_point/baseline/#shapes')
-  check_eq(#drawing.points, 2, 'F - test_undo_move_point/baseline/#points')
-  check_eq(drawing.shapes[1].mode, 'line', 'F - test_undo_move_point/baseline/shape:1')
+  check_eq(#drawing.shapes, 1, 'baseline/#shapes')
+  check_eq(#drawing.points, 2, 'baseline/#points')
+  check_eq(drawing.shapes[1].mode, 'line', 'baseline/shape:1')
   local p1 = drawing.points[drawing.shapes[1].p1]
   local p2 = drawing.points[drawing.shapes[1].p2]
-  check_eq(p1.x, 5, 'F - test_undo_move_point/baseline/p1:x')
-  check_eq(p1.y, 6, 'F - test_undo_move_point/baseline/p1:y')
-  check_eq(p2.x, 35, 'F - test_undo_move_point/baseline/p2:x')
-  check_eq(p2.y, 36, 'F - test_undo_move_point/baseline/p2:y')
-  check_nil(p2.name, 'F - test_undo_move_point/baseline/p2:name')
+  check_eq(p1.x, 5, 'baseline/p1:x')
+  check_eq(p1.y, 6, 'baseline/p1:y')
+  check_eq(p2.x, 35, 'baseline/p2:x')
+  check_eq(p2.y, 36, 'baseline/p2:y')
+  check_nil(p2.name, 'baseline/p2:name')
   -- move p2
   edit.run_after_keychord(Editor_state, 'C-u')
   App.mouse_move(Editor_state.left+26, Editor_state.top+Drawing_padding_top+44)
   edit.update(Editor_state, 0.05)
   local p2 = drawing.points[drawing.shapes[1].p2]
-  check_eq(p2.x, 26, 'F - test_undo_move_point/x')
-  check_eq(p2.y, 44, 'F - test_undo_move_point/y')
+  check_eq(p2.x, 26, 'x')
+  check_eq(p2.y, 44, 'y')
   -- exit 'move' mode
   edit.run_after_mouse_click(Editor_state, Editor_state.left+26, Editor_state.top+Drawing_padding_top+44, 1)
-  check_eq(Editor_state.next_history, 4, 'F - test_undo_move_point/next_history')
+  check_eq(Editor_state.next_history, 4, 'next_history')
   -- undo
   edit.run_after_keychord(Editor_state, 'C-z')
   edit.run_after_keychord(Editor_state, 'C-z')  -- bug: need to undo twice
   local drawing = Editor_state.lines[1]
   local p2 = drawing.points[drawing.shapes[1].p2]
-  check_eq(Editor_state.next_history, 2, 'F - test_undo_move_point/next_history')
-  check_eq(p2.x, 35, 'F - test_undo_move_point/x')
-  check_eq(p2.y, 36, 'F - test_undo_move_point/y')
+  check_eq(Editor_state.next_history, 2, 'next_history')
+  check_eq(p2.x, 35, 'x')
+  check_eq(p2.y, 36, 'y')
   -- wait until save
   Current_time = Current_time + 3.1
   edit.update(Editor_state, 0)
@@ -741,12 +720,11 @@ function test_undo_move_point()
   load_from_disk(Editor_state)
   Text.redraw_all(Editor_state)
   local p2 = Editor_state.lines[1].points[drawing.shapes[1].p2]
-  check_eq(p2.x, 35, 'F - test_undo_move_point/save/x')
-  check_eq(p2.y, 36, 'F - test_undo_move_point/save/y')
+  check_eq(p2.x, 35, 'save/x')
+  check_eq(p2.y, 36, 'save/y')
 end
 
 function test_undo_delete_point()
-  io.write('\ntest_undo_delete_point')
   -- create a drawing with two lines connected at a point
   App.screen.init{width=Test_margin_left+256, height=300}  -- drawing coordinates 1:1 with pixels
   Editor_state = edit.initialize_test_state()
@@ -760,26 +738,26 @@ function test_undo_delete_point()
   edit.run_after_mouse_press(Editor_state, Editor_state.left+35, Editor_state.top+Drawing_padding_top+36, 1)
   edit.run_after_mouse_release(Editor_state, Editor_state.left+55, Editor_state.top+Drawing_padding_top+26, 1)
   local drawing = Editor_state.lines[1]
-  check_eq(#drawing.shapes, 2, 'F - test_undo_delete_point/baseline/#shapes')
-  check_eq(drawing.shapes[1].mode, 'line', 'F - test_undo_delete_point/baseline/shape:1')
-  check_eq(drawing.shapes[2].mode, 'line', 'F - test_undo_delete_point/baseline/shape:2')
+  check_eq(#drawing.shapes, 2, 'baseline/#shapes')
+  check_eq(drawing.shapes[1].mode, 'line', 'baseline/shape:1')
+  check_eq(drawing.shapes[2].mode, 'line', 'baseline/shape:2')
   -- hover on the common point and delete
   App.mouse_move(Editor_state.left+35, Editor_state.top+Drawing_padding_top+36)
   edit.run_after_keychord(Editor_state, 'C-d')
-  check_eq(drawing.shapes[1].mode, 'deleted', 'F - test_undo_delete_point/shape:1')
-  check_eq(drawing.shapes[2].mode, 'deleted', 'F - test_undo_delete_point/shape:2')
+  check_eq(drawing.shapes[1].mode, 'deleted', 'shape:1')
+  check_eq(drawing.shapes[2].mode, 'deleted', 'shape:2')
   -- undo
   edit.run_after_keychord(Editor_state, 'C-z')
   local drawing = Editor_state.lines[1]
   local p2 = drawing.points[drawing.shapes[1].p2]
-  check_eq(Editor_state.next_history, 3, 'F - test_undo_move_point/next_history')
-  check_eq(drawing.shapes[1].mode, 'line', 'F - test_undo_delete_point/shape:1')
-  check_eq(drawing.shapes[2].mode, 'line', 'F - test_undo_delete_point/shape:2')
+  check_eq(Editor_state.next_history, 3, 'next_history')
+  check_eq(drawing.shapes[1].mode, 'line', 'shape:1')
+  check_eq(drawing.shapes[2].mode, 'line', 'shape:2')
   -- wait until save
   Current_time = Current_time + 3.1
   edit.update(Editor_state, 0)
   -- undo is saved
   load_from_disk(Editor_state)
   Text.redraw_all(Editor_state)
-  check_eq(#Editor_state.lines[1].shapes, 2, 'F - test_undo_delete_point/save')
+  check_eq(#Editor_state.lines[1].shapes, 2, 'save')
 end
diff --git a/run_tests.lua b/run_tests.lua
index eab71ae..c5c4eff 100644
--- a/run_tests.lua
+++ b/run_tests.lua
@@ -1,24 +1,22 @@
 function test_resize_window()
-  io.write('\ntest_resize_window')
   App.screen.init{width=300, height=300}
   Editor_state = edit.initialize_test_state()
   Editor_state.filename = 'foo'
-  check_eq(App.screen.width, 300, 'F - test_resize_window/baseline/width')
-  check_eq(App.screen.height, 300, 'F - test_resize_window/baseline/height')
-  check_eq(Editor_state.left, Test_margin_left, 'F - test_resize_window/baseline/left_margin')
-  check_eq(Editor_state.right, 300 - Test_margin_right, 'F - test_resize_window/baseline/left_margin')
+  check_eq(App.screen.width, 300, 'baseline/width')
+  check_eq(App.screen.height, 300, 'baseline/height')
+  check_eq(Editor_state.left, Test_margin_left, 'baseline/left_margin')
+  check_eq(Editor_state.right, 300 - Test_margin_right, 'baseline/left_margin')
   App.resize(200, 400)
   -- ugly; resize switches to real, non-test margins
-  check_eq(App.screen.width, 200, 'F - test_resize_window/width')
-  check_eq(App.screen.height, 400, 'F - test_resize_window/height')
-  check_eq(Editor_state.left, Margin_left, 'F - test_resize_window/left_margin')
-  check_eq(Editor_state.right, 200-Margin_right, 'F - test_resize_window/right_margin')
-  check_eq(Editor_state.width, 200-Margin_left-Margin_right, 'F - test_resize_window/drawing_width')
+  check_eq(App.screen.width, 200, 'width')
+  check_eq(App.screen.height, 400, 'height')
+  check_eq(Editor_state.left, Margin_left, 'left_margin')
+  check_eq(Editor_state.right, 200-Margin_right, 'right_margin')
+  check_eq(Editor_state.width, 200-Margin_left-Margin_right, 'drawing_width')
   -- TODO: how to make assertions about when App.update got past the early exit?
 end
 
 function test_drop_file()
-  io.write('\ntest_drop_file')
   App.screen.init{width=Editor_state.left+300, height=300}
   Editor_state = edit.initialize_test_state()
   App.filesystem['foo'] = 'abc\ndef\nghi\n'
@@ -39,15 +37,14 @@ function test_drop_file()
             end,
   }
   App.filedropped(fake_dropped_file)
-  check_eq(#Editor_state.lines, 3, 'F - test_drop_file/#lines')
-  check_eq(Editor_state.lines[1].data, 'abc', 'F - test_drop_file/lines:1')
-  check_eq(Editor_state.lines[2].data, 'def', 'F - test_drop_file/lines:2')
-  check_eq(Editor_state.lines[3].data, 'ghi', 'F - test_drop_file/lines:3')
+  check_eq(#Editor_state.lines, 3, '#lines')
+  check_eq(Editor_state.lines[1].data, 'abc', 'lines:1')
+  check_eq(Editor_state.lines[2].data, 'def', 'lines:2')
+  check_eq(Editor_state.lines[3].data, 'ghi', 'lines:3')
   edit.draw(Editor_state)
 end
 
 function test_drop_file_saves_previous()
-  io.write('\ntest_drop_file_saves_previous')
   App.screen.init{width=Editor_state.left+300, height=300}
   -- initially editing a file called foo that hasn't been saved to filesystem yet
   Editor_state.lines = load_array{'abc', 'def'}
@@ -73,5 +70,5 @@ function test_drop_file_saves_previous()
   }
   App.filedropped(fake_dropped_file)
   -- filesystem now contains a file called foo
-  check_eq(App.filesystem['foo'], 'abc\ndef\n', 'F - test_drop_file_saves_previous')
+  check_eq(App.filesystem['foo'], 'abc\ndef\n', 'check')
 end
diff --git a/source_tests.lua b/source_tests.lua
index b6e5861..bf3ae3e 100644
--- a/source_tests.lua
+++ b/source_tests.lua
@@ -1,25 +1,23 @@
 function test_resize_window()
-  io.write('\ntest_resize_window')
   App.screen.init{width=300, height=300}
   Editor_state = edit.initialize_test_state()
   Editor_state.filename = 'foo'
   Log_browser_state = edit.initialize_test_state()
-  check_eq(App.screen.width, 300, 'F - test_resize_window/baseline/width')
-  check_eq(App.screen.height, 300, 'F - test_resize_window/baseline/height')
-  check_eq(Editor_state.left, Test_margin_left, 'F - test_resize_window/baseline/left_margin')
-  check_eq(Editor_state.right, 300 - Test_margin_right, 'F - test_resize_window/baseline/right_margin')
+  check_eq(App.screen.width, 300, 'baseline/width')
+  check_eq(App.screen.height, 300, 'baseline/height')
+  check_eq(Editor_state.left, Test_margin_left, 'baseline/left_margin')
+  check_eq(Editor_state.right, 300 - Test_margin_right, 'baseline/right_margin')
   App.resize(200, 400)
   -- ugly; resize switches to real, non-test margins
-  check_eq(App.screen.width, 200, 'F - test_resize_window/width')
-  check_eq(App.screen.height, 400, 'F - test_resize_window/height')
-  check_eq(Editor_state.left, Margin_left, 'F - test_resize_window/left_margin')
-  check_eq(Editor_state.right, 200-Margin_right, 'F - test_resize_window/right_margin')
-  check_eq(Editor_state.width, 200-Margin_left-Margin_right, 'F - test_resize_window/drawing_width')
+  check_eq(App.screen.width, 200, 'width')
+  check_eq(App.screen.height, 400, 'height')
+  check_eq(Editor_state.left, Margin_left, 'left_margin')
+  check_eq(Editor_state.right, 200-Margin_right, 'right_margin')
+  check_eq(Editor_state.width, 200-Margin_left-Margin_right, 'drawing_width')
   -- TODO: how to make assertions about when App.update got past the early exit?
 end
 
 function test_show_log_browser_side()
-  io.write('\ntest_show_log_browser_side')
   App.screen.init{width=300, height=300}
   Display_width = App.screen.width
   Current_app = 'source'
@@ -29,15 +27,14 @@ function test_show_log_browser_side()
   Log_browser_state = edit.initialize_test_state()
   Text.redraw_all(Log_browser_state)
   log_browser.parse(Log_browser_state)
-  check(not Show_log_browser_side, 'F - test_show_log_browser_side/baseline')
+  check(not Show_log_browser_side, 'baseline')
   -- pressing ctrl+l shows log-browser side
   Current_time = Current_time + 0.1
   App.run_after_keychord('C-l')
-  check(Show_log_browser_side, 'F - test_show_log_browser_side')
+  check(Show_log_browser_side, 'check')
 end
 
 function test_show_log_browser_side_doubles_window_width_if_possible()
-  io.write('\ntest_show_log_browser_side_doubles_window_width_if_possible')
   -- initialize screen dimensions to half width
   App.screen.init{width=300, height=300}
   Display_width = App.screen.width*2
@@ -59,17 +56,16 @@ function test_show_log_browser_side_doubles_window_width_if_possible()
   Current_time = Current_time + 0.1
   App.run_after_keychord('C-l')
   -- window width is doubled
-  check_eq(App.screen.width, 600, 'F - test_show_log_browser_side_doubles_window_width_if_possible/display:width')
+  check_eq(App.screen.width, 600, 'display:width')
   -- left side margins are unchanged
-  check_eq(Editor_state.left, Margin_left, 'F - test_show_log_browser_side_doubles_window_width_if_possible/edit:left')
-  check_eq(Editor_state.right, old_editor_right, 'F - test_show_log_browser_side_doubles_window_width_if_possible/edit:right')
+  check_eq(Editor_state.left, Margin_left, 'edit:left')
+  check_eq(Editor_state.right, old_editor_right, 'edit:right')
   -- log browser margins are adjusted
-  check_eq(Log_browser_state.left, App.screen.width/2 + Margin_left, 'F - test_show_log_browser_side_doubles_window_width_if_possible/log:left')
-  check_eq(Log_browser_state.right, App.screen.width - Margin_right, 'F - test_show_log_browser_side_doubles_window_width_if_possible/log:right')
+  check_eq(Log_browser_state.left, App.screen.width/2 + Margin_left, 'log:left')
+  check_eq(Log_browser_state.right, App.screen.width - Margin_right, 'log:right')
 end
 
 function test_show_log_browser_side_resizes_both_sides_if_cannot_double_window_width()
-  io.write('\ntest_show_log_browser_side_resizes_both_sides_if_cannot_double_window_width')
   -- initialize screen dimensions and indicate that it is maximized
   App.screen.init{width=300, height=300}
   Display_width = 300
@@ -90,14 +86,13 @@ function test_show_log_browser_side_resizes_both_sides_if_cannot_double_window_w
   Current_time = Current_time + 0.1
   App.run_after_keychord('C-l')
   -- margins are now adjusted
-  check_eq(Editor_state.left, Margin_left, 'F - test_show_log_browser_side_resizes_both_sides_if_cannot_double_window_width/edit:left')
-  check_eq(Editor_state.right, App.screen.width/2 - Margin_right, 'F - test_show_log_browser_side_resizes_both_sides_if_cannot_double_window_width/edit:right')
-  check_eq(Log_browser_state.left, App.screen.width/2 + Margin_left, 'F - test_show_log_browser_side_resizes_both_sides_if_cannot_double_window_width/log:left')
-  check_eq(Log_browser_state.right, App.screen.width - Margin_right, 'F - test_show_log_browser_side_resizes_both_sides_if_cannot_double_window_width/log:right')
+  check_eq(Editor_state.left, Margin_left, 'edit:left')
+  check_eq(Editor_state.right, App.screen.width/2 - Margin_right, 'edit:right')
+  check_eq(Log_browser_state.left, App.screen.width/2 + Margin_left, 'log:left')
+  check_eq(Log_browser_state.right, App.screen.width - Margin_right, 'log:right')
 end
 
 function test_drop_file()
-  io.write('\ntest_drop_file')
   App.screen.init{width=Editor_state.left+300, height=300}
   Editor_state = edit.initialize_test_state()
   App.filesystem['foo'] = 'abc\ndef\nghi\n'
@@ -118,15 +113,14 @@ function test_drop_file()
             end,
   }
   App.filedropped(fake_dropped_file)
-  check_eq(#Editor_state.lines, 3, 'F - test_drop_file/#lines')
-  check_eq(Editor_state.lines[1].data, 'abc', 'F - test_drop_file/lines:1')
-  check_eq(Editor_state.lines[2].data, 'def', 'F - test_drop_file/lines:2')
-  check_eq(Editor_state.lines[3].data, 'ghi', 'F - test_drop_file/lines:3')
+  check_eq(#Editor_state.lines, 3, '#lines')
+  check_eq(Editor_state.lines[1].data, 'abc', 'lines:1')
+  check_eq(Editor_state.lines[2].data, 'def', 'lines:2')
+  check_eq(Editor_state.lines[3].data, 'ghi', 'lines:3')
   edit.draw(Editor_state)
 end
 
 function test_drop_file_saves_previous()
-  io.write('\ntest_drop_file_saves_previous')
   App.screen.init{width=Editor_state.left+300, height=300}
   -- initially editing a file called foo that hasn't been saved to filesystem yet
   Editor_state.lines = load_array{'abc', 'def'}
@@ -152,5 +146,5 @@ function test_drop_file_saves_previous()
   }
   App.filedropped(fake_dropped_file)
   -- filesystem now contains a file called foo
-  check_eq(App.filesystem['foo'], 'abc\ndef\n', 'F - test_drop_file_saves_previous')
+  check_eq(App.filesystem['foo'], 'abc\ndef\n', 'check')
 end
diff --git a/source_text_tests.lua b/source_text_tests.lua
index 795fc0c..b2fdcda 100644
--- a/source_text_tests.lua
+++ b/source_text_tests.lua
@@ -1,21 +1,19 @@
 -- major tests for text editing flows
 
 function test_initial_state()
-  io.write('\ntest_initial_state')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{}
   Text.redraw_all(Editor_state)
   edit.draw(Editor_state)
-  check_eq(#Editor_state.lines, 1, 'F - test_initial_state/#lines')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_initial_state/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_initial_state/cursor:pos')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_initial_state/screen_top:line')
-  check_eq(Editor_state.screen_top1.pos, 1, 'F - test_initial_state/screen_top:pos')
+  check_eq(#Editor_state.lines, 1, '#lines')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top:line')
+  check_eq(Editor_state.screen_top1.pos, 1, 'screen_top:pos')
 end
 
 function test_click_to_create_drawing()
-  io.write('\ntest_click_to_create_drawing')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{}
@@ -23,12 +21,11 @@ function test_click_to_create_drawing()
   edit.draw(Editor_state)
   edit.run_after_mouse_click(Editor_state, 8,Editor_state.top+8, 1)
   -- cursor skips drawing to always remain on text
-  check_eq(#Editor_state.lines, 2, 'F - test_click_to_create_drawing/#lines')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_click_to_create_drawing/cursor')
+  check_eq(#Editor_state.lines, 2, '#lines')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor')
 end
 
 function test_backspace_to_delete_drawing()
-  io.write('\ntest_backspace_to_delete_drawing')
   -- display a drawing followed by a line of text (you shouldn't ever have a drawing right at the end)
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
@@ -38,12 +35,11 @@ function test_backspace_to_delete_drawing()
   Editor_state.cursor1.line = 2
   -- backspacing deletes the drawing
   edit.run_after_keychord(Editor_state, 'backspace')
-  check_eq(#Editor_state.lines, 1, 'F - test_backspace_to_delete_drawing/#lines')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_backspace_to_delete_drawing/cursor')
+  check_eq(#Editor_state.lines, 1, '#lines')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor')
 end
 
 function test_backspace_from_start_of_final_line()
-  io.write('\ntest_backspace_from_start_of_final_line')
   -- display final line of text with cursor at start of it
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
@@ -53,13 +49,12 @@ function test_backspace_from_start_of_final_line()
   Text.redraw_all(Editor_state)
   -- backspace scrolls up
   edit.run_after_keychord(Editor_state, 'backspace')
-  check_eq(#Editor_state.lines, 1, 'F - test_backspace_from_start_of_final_line/#lines')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_backspace_from_start_of_final_line/cursor')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_backspace_from_start_of_final_line/screen_top')
+  check_eq(#Editor_state.lines, 1, '#lines')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
 end
 
 function test_insert_first_character()
-  io.write('\ntest_insert_first_character')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{}
@@ -67,11 +62,10 @@ function test_insert_first_character()
   edit.draw(Editor_state)
   edit.run_after_text_input(Editor_state, 'a')
   local y = Editor_state.top
-  App.screen.check(y, 'a', 'F - test_insert_first_character/screen:1')
+  App.screen.check(y, 'a', 'screen:1')
 end
 
 function test_press_ctrl()
-  io.write('\ntest_press_ctrl')
   -- press ctrl while the cursor is on text
   App.screen.init{width=50, height=80}
   Editor_state = edit.initialize_test_state()
@@ -84,7 +78,6 @@ function test_press_ctrl()
 end
 
 function test_move_left()
-  io.write('\ntest_move_left')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'a'}
@@ -92,11 +85,10 @@ function test_move_left()
   Editor_state.cursor1 = {line=1, pos=2}
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'left')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_move_left')
+  check_eq(Editor_state.cursor1.pos, 1, 'check')
 end
 
 function test_move_right()
-  io.write('\ntest_move_right')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'a'}
@@ -104,11 +96,10 @@ function test_move_right()
   Editor_state.cursor1 = {line=1, pos=1}
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'right')
-  check_eq(Editor_state.cursor1.pos, 2, 'F - test_move_right')
+  check_eq(Editor_state.cursor1.pos, 2, 'check')
 end
 
 function test_move_left_to_previous_line()
-  io.write('\ntest_move_left_to_previous_line')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def'}
@@ -116,12 +107,11 @@ function test_move_left_to_previous_line()
   Editor_state.cursor1 = {line=2, pos=1}
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'left')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_move_left_to_previous_line/line')
-  check_eq(Editor_state.cursor1.pos, 4, 'F - test_move_left_to_previous_line/pos')  -- past end of line
+  check_eq(Editor_state.cursor1.line, 1, 'line')
+  check_eq(Editor_state.cursor1.pos, 4, 'pos')  -- past end of line
 end
 
 function test_move_right_to_next_line()
-  io.write('\ntest_move_right_to_next_line')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def'}
@@ -129,12 +119,11 @@ function test_move_right_to_next_line()
   Editor_state.cursor1 = {line=1, pos=4}  -- past end of line
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'right')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_move_right_to_next_line/line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_move_right_to_next_line/pos')
+  check_eq(Editor_state.cursor1.line, 2, 'line')
+  check_eq(Editor_state.cursor1.pos, 1, 'pos')
 end
 
 function test_move_to_start_of_word()
-  io.write('\ntest_move_to_start_of_word')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc'}
@@ -142,11 +131,10 @@ function test_move_to_start_of_word()
   Editor_state.cursor1 = {line=1, pos=3}
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-left')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_move_to_start_of_word')
+  check_eq(Editor_state.cursor1.pos, 1, 'check')
 end
 
 function test_move_to_start_of_previous_word()
-  io.write('\ntest_move_to_start_of_previous_word')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc def'}
@@ -154,11 +142,10 @@ function test_move_to_start_of_previous_word()
   Editor_state.cursor1 = {line=1, pos=4}  -- at the space between words
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-left')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_move_to_start_of_previous_word')
+  check_eq(Editor_state.cursor1.pos, 1, 'check')
 end
 
 function test_skip_to_previous_word()
-  io.write('\ntest_skip_to_previous_word')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc def'}
@@ -166,11 +153,10 @@ function test_skip_to_previous_word()
   Editor_state.cursor1 = {line=1, pos=5}  -- at the start of second word
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-left')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_skip_to_previous_word')
+  check_eq(Editor_state.cursor1.pos, 1, 'check')
 end
 
 function test_skip_past_tab_to_previous_word()
-  io.write('\ntest_skip_past_tab_to_previous_word')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc def\tghi'}
@@ -178,11 +164,10 @@ function test_skip_past_tab_to_previous_word()
   Editor_state.cursor1 = {line=1, pos=10}  -- within third word
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-left')
-  check_eq(Editor_state.cursor1.pos, 9, 'F - test_skip_past_tab_to_previous_word')
+  check_eq(Editor_state.cursor1.pos, 9, 'check')
 end
 
 function test_skip_multiple_spaces_to_previous_word()
-  io.write('\ntest_skip_multiple_spaces_to_previous_word')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc  def'}
@@ -190,11 +175,10 @@ function test_skip_multiple_spaces_to_previous_word()
   Editor_state.cursor1 = {line=1, pos=6}  -- at the start of second word
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-left')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_skip_multiple_spaces_to_previous_word')
+  check_eq(Editor_state.cursor1.pos, 1, 'check')
 end
 
 function test_move_to_start_of_word_on_previous_line()
-  io.write('\ntest_move_to_start_of_word_on_previous_line')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc def', 'ghi'}
@@ -202,12 +186,11 @@ function test_move_to_start_of_word_on_previous_line()
   Editor_state.cursor1 = {line=2, pos=1}
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-left')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_move_to_start_of_word_on_previous_line/line')
-  check_eq(Editor_state.cursor1.pos, 5, 'F - test_move_to_start_of_word_on_previous_line/pos')
+  check_eq(Editor_state.cursor1.line, 1, 'line')
+  check_eq(Editor_state.cursor1.pos, 5, 'pos')
 end
 
 function test_move_past_end_of_word()
-  io.write('\ntest_move_past_end_of_word')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc def'}
@@ -215,11 +198,10 @@ function test_move_past_end_of_word()
   Editor_state.cursor1 = {line=1, pos=1}
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-right')
-  check_eq(Editor_state.cursor1.pos, 4, 'F - test_move_past_end_of_word')
+  check_eq(Editor_state.cursor1.pos, 4, 'check')
 end
 
 function test_skip_to_next_word()
-  io.write('\ntest_skip_to_next_word')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc def'}
@@ -227,11 +209,10 @@ function test_skip_to_next_word()
   Editor_state.cursor1 = {line=1, pos=4}  -- at the space between words
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-right')
-  check_eq(Editor_state.cursor1.pos, 8, 'F - test_skip_to_next_word')
+  check_eq(Editor_state.cursor1.pos, 8, 'check')
 end
 
 function test_skip_past_tab_to_next_word()
-  io.write('\ntest_skip_past_tab_to_next_word')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc\tdef'}
@@ -239,11 +220,10 @@ function test_skip_past_tab_to_next_word()
   Editor_state.cursor1 = {line=1, pos=1}  -- at the space between words
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-right')
-  check_eq(Editor_state.cursor1.pos, 4, 'F - test_skip_past_tab_to_next_word')
+  check_eq(Editor_state.cursor1.pos, 4, 'check')
 end
 
 function test_skip_multiple_spaces_to_next_word()
-  io.write('\ntest_skip_multiple_spaces_to_next_word')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc  def'}
@@ -251,11 +231,10 @@ function test_skip_multiple_spaces_to_next_word()
   Editor_state.cursor1 = {line=1, pos=4}  -- at the start of second word
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-right')
-  check_eq(Editor_state.cursor1.pos, 9, 'F - test_skip_multiple_spaces_to_next_word')
+  check_eq(Editor_state.cursor1.pos, 9, 'check')
 end
 
 function test_move_past_end_of_word_on_next_line()
-  io.write('\ntest_move_past_end_of_word_on_next_line')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc def', 'ghi'}
@@ -263,12 +242,11 @@ function test_move_past_end_of_word_on_next_line()
   Editor_state.cursor1 = {line=1, pos=8}
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-right')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_move_past_end_of_word_on_next_line/line')
-  check_eq(Editor_state.cursor1.pos, 4, 'F - test_move_past_end_of_word_on_next_line/pos')
+  check_eq(Editor_state.cursor1.line, 2, 'line')
+  check_eq(Editor_state.cursor1.pos, 4, 'pos')
 end
 
 function test_click_moves_cursor()
-  io.write('\ntest_click_moves_cursor')
   App.screen.init{width=50, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'xyz'}
@@ -279,15 +257,14 @@ function test_click_moves_cursor()
   Editor_state.selection1 = {}
   edit.draw(Editor_state)  -- populate line_cache.starty for each line Editor_state.line_cache
   edit.run_after_mouse_release(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_click_moves_cursor/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 2, 'F - test_click_moves_cursor/cursor:pos')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
   -- selection is empty to avoid perturbing future edits
-  check_nil(Editor_state.selection1.line, 'F - test_click_moves_cursor/selection:line')
-  check_nil(Editor_state.selection1.pos, 'F - test_click_moves_cursor/selection:pos')
+  check_nil(Editor_state.selection1.line, 'selection:line')
+  check_nil(Editor_state.selection1.pos, 'selection:pos')
 end
 
 function test_click_to_left_of_line()
-  io.write('\ntest_click_to_left_of_line')
   -- display a line with the cursor in the middle
   App.screen.init{width=50, height=80}
   Editor_state = edit.initialize_test_state()
@@ -300,13 +277,12 @@ function test_click_to_left_of_line()
   edit.draw(Editor_state)
   edit.run_after_mouse_click(Editor_state, Editor_state.left-4,Editor_state.top+5, 1)
   -- cursor moves to start of line
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_click_to_left_of_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_click_to_left_of_line/cursor:pos')
-  check_nil(Editor_state.selection1.line, 'F - test_click_to_left_of_line/selection is empty to avoid perturbing future edits')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
+  check_nil(Editor_state.selection1.line, 'selection is empty to avoid perturbing future edits')
 end
 
 function test_click_takes_margins_into_account()
-  io.write('\ntest_click_takes_margins_into_account')
   -- display two lines with cursor on one of them
   App.screen.init{width=100, height=80}
   Editor_state = edit.initialize_test_state()
@@ -320,13 +296,12 @@ function test_click_takes_margins_into_account()
   edit.draw(Editor_state)
   edit.run_after_mouse_click(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
   -- cursor moves
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_click_takes_margins_into_account/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 2, 'F - test_click_takes_margins_into_account/cursor:pos')
-  check_nil(Editor_state.selection1.line, 'F - test_click_takes_margins_into_account/selection is empty to avoid perturbing future edits')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
+  check_nil(Editor_state.selection1.line, 'selection is empty to avoid perturbing future edits')
 end
 
 function test_click_on_empty_line()
-  io.write('\ntest_click_on_empty_line')
   -- display two lines with the first one empty
   App.screen.init{width=50, height=80}
   Editor_state = edit.initialize_test_state()
@@ -339,11 +314,10 @@ function test_click_on_empty_line()
   edit.draw(Editor_state)
   edit.run_after_mouse_click(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
   -- cursor moves
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_click_on_empty_line/cursor')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor')
 end
 
 function test_draw_text()
-  io.write('\ntest_draw_text')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'ghi'}
@@ -353,15 +327,14 @@ function test_draw_text()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_draw_text/screen:1')
+  App.screen.check(y, 'abc', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_draw_text/screen:2')
+  App.screen.check(y, 'def', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_draw_text/screen:3')
+  App.screen.check(y, 'ghi', 'screen:3')
 end
 
 function test_draw_wrapping_text()
-  io.write('\ntest_draw_wrapping_text')
   App.screen.init{width=50, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'defgh', 'xyz'}
@@ -371,15 +344,14 @@ function test_draw_wrapping_text()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_draw_wrapping_text/screen:1')
+  App.screen.check(y, 'abc', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'de', 'F - test_draw_wrapping_text/screen:2')
+  App.screen.check(y, 'de', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'fgh', 'F - test_draw_wrapping_text/screen:3')
+  App.screen.check(y, 'fgh', 'screen:3')
 end
 
 function test_draw_word_wrapping_text()
-  io.write('\ntest_draw_word_wrapping_text')
   App.screen.init{width=60, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc def ghi', 'jkl'}
@@ -389,15 +361,14 @@ function test_draw_word_wrapping_text()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc ', 'F - test_draw_word_wrapping_text/screen:1')
+  App.screen.check(y, 'abc ', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def ', 'F - test_draw_word_wrapping_text/screen:2')
+  App.screen.check(y, 'def ', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_draw_word_wrapping_text/screen:3')
+  App.screen.check(y, 'ghi', 'screen:3')
 end
 
 function test_click_on_wrapping_line()
-  io.write('\ntest_click_on_wrapping_line')
   -- display two lines with cursor on one of them
   App.screen.init{width=50, height=80}
   Editor_state = edit.initialize_test_state()
@@ -410,13 +381,12 @@ function test_click_on_wrapping_line()
   edit.draw(Editor_state)
   edit.run_after_mouse_click(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
   -- cursor moves
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_click_on_wrapping_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 2, 'F - test_click_on_wrapping_line/cursor:pos')
-  check_nil(Editor_state.selection1.line, 'F - test_click_on_wrapping_line/selection is empty to avoid perturbing future edits')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
+  check_nil(Editor_state.selection1.line, 'selection is empty to avoid perturbing future edits')
 end
 
 function test_click_on_wrapping_line_takes_margins_into_account()
-  io.write('\ntest_click_on_wrapping_line_takes_margins_into_account')
   -- display two lines with cursor on one of them
   App.screen.init{width=100, height=80}
   Editor_state = edit.initialize_test_state()
@@ -430,14 +400,13 @@ function test_click_on_wrapping_line_takes_margins_into_account()
   edit.draw(Editor_state)
   edit.run_after_mouse_click(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
   -- cursor moves
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_click_on_wrapping_line_takes_margins_into_account/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 2, 'F - test_click_on_wrapping_line_takes_margins_into_account/cursor:pos')
-  check_nil(Editor_state.selection1.line, 'F - test_click_on_wrapping_line_takes_margins_into_account/selection is empty to avoid perturbing future edits')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
+  check_nil(Editor_state.selection1.line, 'selection is empty to avoid perturbing future edits')
 end
 
 function test_draw_text_wrapping_within_word()
   -- arrange a screen line that needs to be split within a word
-  io.write('\ntest_draw_text_wrapping_within_word')
   App.screen.init{width=60, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abcd e fghijk', 'xyz'}
@@ -447,16 +416,15 @@ function test_draw_text_wrapping_within_word()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abcd ', 'F - test_draw_text_wrapping_within_word/screen:1')
+  App.screen.check(y, 'abcd ', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'e fgh', 'F - test_draw_text_wrapping_within_word/screen:2')
+  App.screen.check(y, 'e fgh', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ijk', 'F - test_draw_text_wrapping_within_word/screen:3')
+  App.screen.check(y, 'ijk', 'screen:3')
 end
 
 function test_draw_wrapping_text_containing_non_ascii()
   -- draw a long line containing non-ASCII
-  io.write('\ntest_draw_wrapping_text_containing_non_ascii')
   App.screen.init{width=60, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'madam I’m adam', 'xyz'}  -- notice the non-ASCII apostrophe
@@ -466,15 +434,14 @@ function test_draw_wrapping_text_containing_non_ascii()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'mad', 'F - test_draw_wrapping_text_containing_non_ascii/screen:1')
+  App.screen.check(y, 'mad', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'am I', 'F - test_draw_wrapping_text_containing_non_ascii/screen:2')
+  App.screen.check(y, 'am I', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, '’m a', 'F - test_draw_wrapping_text_containing_non_ascii/screen:3')
+  App.screen.check(y, '’m a', 'screen:3')
 end
 
 function test_click_on_wrapping_line()
-  io.write('\ntest_click_on_wrapping_line')
   -- display a wrapping line
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -486,19 +453,18 @@ function test_click_on_wrapping_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'madam ', 'F - test_click_on_wrapping_line/baseline/screen:1')
+  App.screen.check(y, 'madam ', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, "I'm ad", 'F - test_click_on_wrapping_line/baseline/screen:2')
+  App.screen.check(y, "I'm ad", 'baseline/screen:2')
   y = y + Editor_state.line_height
   -- click past end of second screen line
   edit.run_after_mouse_click(Editor_state, App.screen.width-2,y-2, 1)
   -- cursor moves to end of screen line
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_click_on_wrapping_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 12, 'F - test_click_on_wrapping_line/cursor:pos')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 12, 'cursor:pos')
 end
 
 function test_click_on_wrapping_line_rendered_from_partway_at_top_of_screen()
-  io.write('\ntest_click_on_wrapping_line_rendered_from_partway_at_top_of_screen')
   -- display a wrapping line from its second screen line
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -510,17 +476,16 @@ function test_click_on_wrapping_line_rendered_from_partway_at_top_of_screen()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, "I'm ad", 'F - test_click_on_wrapping_line_rendered_from_partway_at_top_of_screen/baseline/screen:2')
+  App.screen.check(y, "I'm ad", 'baseline/screen:2')
   y = y + Editor_state.line_height
   -- click past end of second screen line
   edit.run_after_mouse_click(Editor_state, App.screen.width-2,y-2, 1)
   -- cursor moves to end of screen line
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_click_on_wrapping_line_rendered_from_partway_at_top_of_screen/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 12, 'F - test_click_on_wrapping_line_rendered_from_partway_at_top_of_screen/cursor:pos')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 12, 'cursor:pos')
 end
 
 function test_click_past_end_of_wrapping_line()
-  io.write('\ntest_click_past_end_of_wrapping_line')
   -- display a wrapping line
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -532,20 +497,19 @@ function test_click_past_end_of_wrapping_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'madam ', 'F - test_click_past_end_of_wrapping_line/baseline/screen:1')
+  App.screen.check(y, 'madam ', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, "I'm ad", 'F - test_click_past_end_of_wrapping_line/baseline/screen:2')
+  App.screen.check(y, "I'm ad", 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'am', 'F - test_click_past_end_of_wrapping_line/baseline/screen:3')
+  App.screen.check(y, 'am', 'baseline/screen:3')
   y = y + Editor_state.line_height
   -- click past the end of it
   edit.run_after_mouse_click(Editor_state, App.screen.width-2,y-2, 1)
   -- cursor moves to end of line
-  check_eq(Editor_state.cursor1.pos, 15, 'F - test_click_past_end_of_wrapping_line/cursor')  -- one more than the number of UTF-8 code-points
+  check_eq(Editor_state.cursor1.pos, 15, 'cursor')  -- one more than the number of UTF-8 code-points
 end
 
 function test_click_past_end_of_wrapping_line_containing_non_ascii()
-  io.write('\ntest_click_past_end_of_wrapping_line_containing_non_ascii')
   -- display a wrapping line containing non-ASCII
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -557,20 +521,19 @@ function test_click_past_end_of_wrapping_line_containing_non_ascii()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'madam ', 'F - test_click_past_end_of_wrapping_line_containing_non_ascii/baseline/screen:1')
+  App.screen.check(y, 'madam ', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'I’m ad', 'F - test_click_past_end_of_wrapping_line_containing_non_ascii/baseline/screen:2')
+  App.screen.check(y, 'I’m ad', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'am', 'F - test_click_past_end_of_wrapping_line_containing_non_ascii/baseline/screen:3')
+  App.screen.check(y, 'am', 'baseline/screen:3')
   y = y + Editor_state.line_height
   -- click past the end of it
   edit.run_after_mouse_click(Editor_state, App.screen.width-2,y-2, 1)
   -- cursor moves to end of line
-  check_eq(Editor_state.cursor1.pos, 15, 'F - test_click_past_end_of_wrapping_line_containing_non_ascii/cursor')  -- one more than the number of UTF-8 code-points
+  check_eq(Editor_state.cursor1.pos, 15, 'cursor')  -- one more than the number of UTF-8 code-points
 end
 
 function test_click_past_end_of_word_wrapping_line()
-  io.write('\ntest_click_past_end_of_word_wrapping_line')
   -- display a long line wrapping at a word boundary on a screen of more realistic length
   App.screen.init{width=160, height=80}
   Editor_state = edit.initialize_test_state()
@@ -583,16 +546,15 @@ function test_click_past_end_of_word_wrapping_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'the quick brown fox ', 'F - test_click_past_end_of_word_wrapping_line/baseline/screen:1')
+  App.screen.check(y, 'the quick brown fox ', 'baseline/screen:1')
   y = y + Editor_state.line_height
   -- click past the end of the screen line
   edit.run_after_mouse_click(Editor_state, App.screen.width-2,y-2, 1)
   -- cursor moves to end of screen line
-  check_eq(Editor_state.cursor1.pos, 20, 'F - test_click_past_end_of_word_wrapping_line/cursor')
+  check_eq(Editor_state.cursor1.pos, 20, 'cursor')
 end
 
 function test_select_text()
-  io.write('\ntest_select_text')
   -- display a line of text
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -608,14 +570,13 @@ function test_select_text()
   App.fake_key_release('lshift')
   edit.key_release(Editor_state, 'lshift')
   -- selection persists even after shift is released
-  check_eq(Editor_state.selection1.line, 1, 'F - test_select_text/selection:line')
-  check_eq(Editor_state.selection1.pos, 1, 'F - test_select_text/selection:pos')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_select_text/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 2, 'F - test_select_text/cursor:pos')
+  check_eq(Editor_state.selection1.line, 1, 'selection:line')
+  check_eq(Editor_state.selection1.pos, 1, 'selection:pos')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
 end
 
 function test_cursor_movement_without_shift_resets_selection()
-  io.write('\ntest_cursor_movement_without_shift_resets_selection')
   -- display a line of text with some part selected
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -629,12 +590,11 @@ function test_cursor_movement_without_shift_resets_selection()
   -- press an arrow key without shift
   edit.run_after_keychord(Editor_state, 'right')
   -- no change to data, selection is reset
-  check_nil(Editor_state.selection1.line, 'F - test_cursor_movement_without_shift_resets_selection')
-  check_eq(Editor_state.lines[1].data, 'abc', 'F - test_cursor_movement_without_shift_resets_selection/data')
+  check_nil(Editor_state.selection1.line, 'check')
+  check_eq(Editor_state.lines[1].data, 'abc', 'data')
 end
 
 function test_edit_deletes_selection()
-  io.write('\ntest_edit_deletes_selection')
   -- display a line of text with some part selected
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -648,11 +608,10 @@ function test_edit_deletes_selection()
   -- press a key
   edit.run_after_text_input(Editor_state, 'x')
   -- selected text is deleted and replaced with the key
-  check_eq(Editor_state.lines[1].data, 'xbc', 'F - test_edit_deletes_selection')
+  check_eq(Editor_state.lines[1].data, 'xbc', 'check')
 end
 
 function test_edit_with_shift_key_deletes_selection()
-  io.write('\ntest_edit_with_shift_key_deletes_selection')
   -- display a line of text with some part selected
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -670,12 +629,11 @@ function test_edit_with_shift_key_deletes_selection()
   edit.key_release(Editor_state, 'd')
   App.fake_key_release('lshift')
   -- selected text is deleted and replaced with the key
-  check_nil(Editor_state.selection1.line, 'F - test_edit_with_shift_key_deletes_selection')
-  check_eq(Editor_state.lines[1].data, 'Dbc', 'F - test_edit_with_shift_key_deletes_selection/data')
+  check_nil(Editor_state.selection1.line, 'check')
+  check_eq(Editor_state.lines[1].data, 'Dbc', 'data')
 end
 
 function test_copy_does_not_reset_selection()
-  io.write('\ntest_copy_does_not_reset_selection')
   -- display a line of text with a selection
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -688,13 +646,12 @@ function test_copy_does_not_reset_selection()
   edit.draw(Editor_state)
   -- copy selection
   edit.run_after_keychord(Editor_state, 'C-c')
-  check_eq(App.clipboard, 'a', 'F - test_copy_does_not_reset_selection/clipboard')
+  check_eq(App.clipboard, 'a', 'clipboard')
   -- selection is reset since shift key is not pressed
-  check(Editor_state.selection1.line, 'F - test_copy_does_not_reset_selection')
+  check(Editor_state.selection1.line, 'check')
 end
 
 function test_cut()
-  io.write('\ntest_cut')
   -- display a line of text with some part selected
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -707,13 +664,12 @@ function test_cut()
   edit.draw(Editor_state)
   -- press a key
   edit.run_after_keychord(Editor_state, 'C-x')
-  check_eq(App.clipboard, 'a', 'F - test_cut/clipboard')
+  check_eq(App.clipboard, 'a', 'clipboard')
   -- selected text is deleted
-  check_eq(Editor_state.lines[1].data, 'bc', 'F - test_cut/data')
+  check_eq(Editor_state.lines[1].data, 'bc', 'data')
 end
 
 function test_paste_replaces_selection()
-  io.write('\ntest_paste_replaces_selection')
   -- display a line of text with a selection
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -730,11 +686,10 @@ function test_paste_replaces_selection()
   edit.run_after_keychord(Editor_state, 'C-v')
   -- selection is reset since shift key is not pressed
   -- selection includes the newline, so it's also deleted
-  check_eq(Editor_state.lines[1].data, 'xyzdef', 'F - test_paste_replaces_selection')
+  check_eq(Editor_state.lines[1].data, 'xyzdef', 'check')
 end
 
 function test_deleting_selection_may_scroll()
-  io.write('\ntest_deleting_selection_may_scroll')
   -- display lines 2/3/4
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
@@ -745,22 +700,21 @@ function test_deleting_selection_may_scroll()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_deleting_selection_may_scroll/baseline/screen:1')
+  App.screen.check(y, 'def', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_deleting_selection_may_scroll/baseline/screen:2')
+  App.screen.check(y, 'ghi', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_deleting_selection_may_scroll/baseline/screen:3')
+  App.screen.check(y, 'jkl', 'baseline/screen:3')
   -- set up a selection starting above the currently displayed page
   Editor_state.selection1 = {line=1, pos=2}
   -- delete selection
   edit.run_after_keychord(Editor_state, 'backspace')
   -- page scrolls up
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_deleting_selection_may_scroll')
-  check_eq(Editor_state.lines[1].data, 'ahi', 'F - test_deleting_selection_may_scroll/data')
+  check_eq(Editor_state.screen_top1.line, 1, 'check')
+  check_eq(Editor_state.lines[1].data, 'ahi', 'data')
 end
 
 function test_edit_wrapping_text()
-  io.write('\ntest_edit_wrapping_text')
   App.screen.init{width=50, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'xyz'}
@@ -771,15 +725,14 @@ function test_edit_wrapping_text()
   edit.draw(Editor_state)
   edit.run_after_text_input(Editor_state, 'g')
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_edit_wrapping_text/screen:1')
+  App.screen.check(y, 'abc', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'de', 'F - test_edit_wrapping_text/screen:2')
+  App.screen.check(y, 'de', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'fg', 'F - test_edit_wrapping_text/screen:3')
+  App.screen.check(y, 'fg', 'screen:3')
 end
 
 function test_insert_newline()
-  io.write('\ntest_insert_newline')
   -- display a few lines
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -790,26 +743,25 @@ function test_insert_newline()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_insert_newline/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_insert_newline/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_insert_newline/baseline/screen:3')
+  App.screen.check(y, 'ghi', 'baseline/screen:3')
   -- hitting the enter key splits the line
   edit.run_after_keychord(Editor_state, 'return')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_insert_newline/screen_top')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_insert_newline/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_insert_newline/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'a', 'F - test_insert_newline/screen:1')
+  App.screen.check(y, 'a', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'bc', 'F - test_insert_newline/screen:2')
+  App.screen.check(y, 'bc', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_insert_newline/screen:3')
+  App.screen.check(y, 'def', 'screen:3')
 end
 
 function test_insert_newline_at_start_of_line()
-  io.write('\ntest_insert_newline_at_start_of_line')
   -- display a line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -820,14 +772,13 @@ function test_insert_newline_at_start_of_line()
   Editor_state.screen_bottom1 = {}
   -- hitting the enter key splits the line
   edit.run_after_keychord(Editor_state, 'return')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_insert_newline_at_start_of_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_insert_newline_at_start_of_line/cursor:pos')
-  check_eq(Editor_state.lines[1].data, '', 'F - test_insert_newline_at_start_of_line/data:1')
-  check_eq(Editor_state.lines[2].data, 'abc', 'F - test_insert_newline_at_start_of_line/data:2')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
+  check_eq(Editor_state.lines[1].data, '', 'data:1')
+  check_eq(Editor_state.lines[2].data, 'abc', 'data:2')
 end
 
 function test_insert_from_clipboard()
-  io.write('\ntest_insert_from_clipboard')
   -- display a few lines
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -838,27 +789,26 @@ function test_insert_from_clipboard()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_insert_from_clipboard/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_insert_from_clipboard/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_insert_from_clipboard/baseline/screen:3')
+  App.screen.check(y, 'ghi', 'baseline/screen:3')
   -- paste some text including a newline, check that new line is created
   App.clipboard = 'xy\nz'
   edit.run_after_keychord(Editor_state, 'C-v')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_insert_from_clipboard/screen_top')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_insert_from_clipboard/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 2, 'F - test_insert_from_clipboard/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'axy', 'F - test_insert_from_clipboard/screen:1')
+  App.screen.check(y, 'axy', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'zbc', 'F - test_insert_from_clipboard/screen:2')
+  App.screen.check(y, 'zbc', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_insert_from_clipboard/screen:3')
+  App.screen.check(y, 'def', 'screen:3')
 end
 
 function test_select_text_using_mouse()
-  io.write('\ntest_select_text_using_mouse')
   App.screen.init{width=50, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'xyz'}
@@ -872,14 +822,13 @@ function test_select_text_using_mouse()
   edit.run_after_mouse_press(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
   -- drag and release somewhere else
   edit.run_after_mouse_release(Editor_state, Editor_state.left+20,Editor_state.top+Editor_state.line_height+5, 1)
-  check_eq(Editor_state.selection1.line, 1, 'F - test_select_text_using_mouse/selection:line')
-  check_eq(Editor_state.selection1.pos, 2, 'F - test_select_text_using_mouse/selection:pos')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_select_text_using_mouse/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 4, 'F - test_select_text_using_mouse/cursor:pos')
+  check_eq(Editor_state.selection1.line, 1, 'selection:line')
+  check_eq(Editor_state.selection1.pos, 2, 'selection:pos')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 4, 'cursor:pos')
 end
 
 function test_select_text_using_mouse_and_shift()
-  io.write('\ntest_select_text_using_mouse_and_shift')
   App.screen.init{width=50, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'xyz'}
@@ -897,14 +846,13 @@ function test_select_text_using_mouse_and_shift()
   edit.run_after_mouse_press(Editor_state, Editor_state.left+20,Editor_state.top+5, 1)
   edit.run_after_mouse_release(Editor_state, Editor_state.left+20,Editor_state.top+Editor_state.line_height+5, 1)
   App.fake_key_release('lshift')
-  check_eq(Editor_state.selection1.line, 1, 'F - test_select_text_using_mouse_and_shift/selection:line')
-  check_eq(Editor_state.selection1.pos, 2, 'F - test_select_text_using_mouse_and_shift/selection:pos')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_select_text_using_mouse_and_shift/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 4, 'F - test_select_text_using_mouse_and_shift/cursor:pos')
+  check_eq(Editor_state.selection1.line, 1, 'selection:line')
+  check_eq(Editor_state.selection1.pos, 2, 'selection:pos')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 4, 'cursor:pos')
 end
 
 function test_select_text_repeatedly_using_mouse_and_shift()
-  io.write('\ntest_select_text_repeatedly_using_mouse_and_shift')
   App.screen.init{width=50, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'xyz'}
@@ -928,14 +876,13 @@ function test_select_text_repeatedly_using_mouse_and_shift()
   edit.run_after_mouse_release(Editor_state, Editor_state.left+8,Editor_state.top+Editor_state.line_height+5, 1)
   App.fake_key_release('lshift')
   -- selection is between first and third location. forget the second location, not the first.
-  check_eq(Editor_state.selection1.line, 1, 'F - test_select_text_repeatedly_using_mouse_and_shift/selection:line')
-  check_eq(Editor_state.selection1.pos, 2, 'F - test_select_text_repeatedly_using_mouse_and_shift/selection:pos')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_select_text_repeatedly_using_mouse_and_shift/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 2, 'F - test_select_text_repeatedly_using_mouse_and_shift/cursor:pos')
+  check_eq(Editor_state.selection1.line, 1, 'selection:line')
+  check_eq(Editor_state.selection1.pos, 2, 'selection:pos')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
 end
 
 function test_cut_without_selection()
-  io.write('\ntest_cut_without_selection')
   -- display a few lines
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -949,11 +896,10 @@ function test_cut_without_selection()
   -- try to cut without selecting text
   edit.run_after_keychord(Editor_state, 'C-x')
   -- no crash
-  check_nil(Editor_state.selection1.line, 'F - test_cut_without_selection')
+  check_nil(Editor_state.selection1.line, 'check')
 end
 
 function test_pagedown()
-  io.write('\ntest_pagedown')
   App.screen.init{width=120, height=45}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'ghi'}
@@ -964,21 +910,20 @@ function test_pagedown()
   -- initially the first two lines are displayed
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_pagedown/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_pagedown/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   -- after pagedown the bottom line becomes the top
   edit.run_after_keychord(Editor_state, 'pagedown')
-  check_eq(Editor_state.screen_top1.line, 2, 'F - test_pagedown/screen_top')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_pagedown/cursor')
+  check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor')
   y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_pagedown/screen:1')
+  App.screen.check(y, 'def', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_pagedown/screen:2')
+  App.screen.check(y, 'ghi', 'screen:2')
 end
 
 function test_pagedown_skips_drawings()
-  io.write('\ntest_pagedown_skips_drawings')
   -- some lines of text with a drawing intermixed
   local drawing_width = 50
   App.screen.init{width=Editor_state.left+drawing_width, height=80}
@@ -988,7 +933,7 @@ function test_pagedown_skips_drawings()
                                   'def',               -- height 15
                                   'ghi'}               -- height 15
   Text.redraw_all(Editor_state)
-  check_eq(Editor_state.lines[2].mode, 'drawing', 'F - test_pagedown_skips_drawings/baseline/lines')
+  check_eq(Editor_state.lines[2].mode, 'drawing', 'baseline/lines')
   Editor_state.cursor1 = {line=1, pos=1}
   Editor_state.screen_top1 = {line=1, pos=1}
   Editor_state.screen_bottom1 = {}
@@ -997,18 +942,17 @@ function test_pagedown_skips_drawings()
   -- 15px margin + 15px line1 + 10px margin + 25px drawing + 10px margin = 75px < screen height 80px
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_pagedown_skips_drawings/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   -- after pagedown the screen draws the drawing up top
   -- 15px margin + 10px margin + 25px drawing + 10px margin + 15px line3 = 75px < screen height 80px
   edit.run_after_keychord(Editor_state, 'pagedown')
-  check_eq(Editor_state.screen_top1.line, 2, 'F - test_pagedown_skips_drawings/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_pagedown_skips_drawings/cursor')
+  check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 3, 'cursor')
   y = Editor_state.top + drawing_height
-  App.screen.check(y, 'def', 'F - test_pagedown_skips_drawings/screen:1')
+  App.screen.check(y, 'def', 'screen:1')
 end
 
 function test_pagedown_can_start_from_middle_of_long_wrapping_line()
-  io.write('\ntest_pagedown_can_start_from_middle_of_long_wrapping_line')
   -- draw a few lines starting from a very long wrapping line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1019,25 +963,24 @@ function test_pagedown_can_start_from_middle_of_long_wrapping_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc ', 'F - test_pagedown_can_start_from_middle_of_long_wrapping_line/baseline/screen:1')
+  App.screen.check(y, 'abc ', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def ', 'F - test_pagedown_can_start_from_middle_of_long_wrapping_line/baseline/screen:2')
+  App.screen.check(y, 'def ', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi ', 'F - test_pagedown_can_start_from_middle_of_long_wrapping_line/baseline/screen:3')
+  App.screen.check(y, 'ghi ', 'baseline/screen:3')
   -- after pagedown we scroll down the very long wrapping line
   edit.run_after_keychord(Editor_state, 'pagedown')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_pagedown_can_start_from_middle_of_long_wrapping_line/screen_top:line')
-  check_eq(Editor_state.screen_top1.pos, 9, 'F - test_pagedown_can_start_from_middle_of_long_wrapping_line/screen_top:pos')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top:line')
+  check_eq(Editor_state.screen_top1.pos, 9, 'screen_top:pos')
   y = Editor_state.top
-  App.screen.check(y, 'ghi ', 'F - test_pagedown_can_start_from_middle_of_long_wrapping_line/screen:1')
+  App.screen.check(y, 'ghi ', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl ', 'F - test_pagedown_can_start_from_middle_of_long_wrapping_line/screen:2')
+  App.screen.check(y, 'jkl ', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno ', 'F - test_pagedown_can_start_from_middle_of_long_wrapping_line/screen:3')
+  App.screen.check(y, 'mno ', 'screen:3')
 end
 
 function test_pagedown_never_moves_up()
-  io.write('\ntest_pagedown_never_moves_up')
   -- draw the final screen line of a wrapping line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1049,12 +992,11 @@ function test_pagedown_never_moves_up()
   edit.draw(Editor_state)
   -- pagedown makes no change
   edit.run_after_keychord(Editor_state, 'pagedown')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_pagedown_never_moves_up/screen_top:line')
-  check_eq(Editor_state.screen_top1.pos, 9, 'F - test_pagedown_never_moves_up/screen_top:pos')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top:line')
+  check_eq(Editor_state.screen_top1.pos, 9, 'screen_top:pos')
 end
 
 function test_down_arrow_moves_cursor()
-  io.write('\ntest_down_arrow_moves_cursor')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'ghi', 'jkl'}
@@ -1065,26 +1007,25 @@ function test_down_arrow_moves_cursor()
   -- initially the first three lines are displayed
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_down_arrow_moves_cursor/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_down_arrow_moves_cursor/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_down_arrow_moves_cursor/baseline/screen:3')
+  App.screen.check(y, 'ghi', 'baseline/screen:3')
   -- after hitting the down arrow, the cursor moves down by 1 line
   edit.run_after_keychord(Editor_state, 'down')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_down_arrow_moves_cursor/screen_top')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_down_arrow_moves_cursor/cursor')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor')
   -- the screen is unchanged
   y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_down_arrow_moves_cursor/screen:1')
+  App.screen.check(y, 'abc', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_down_arrow_moves_cursor/screen:2')
+  App.screen.check(y, 'def', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_down_arrow_moves_cursor/screen:3')
+  App.screen.check(y, 'ghi', 'screen:3')
 end
 
 function test_down_arrow_scrolls_down_by_one_line()
-  io.write('\ntest_down_arrow_scrolls_down_by_one_line')
   -- display the first three lines with the cursor on the bottom line
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1095,25 +1036,24 @@ function test_down_arrow_scrolls_down_by_one_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_down_arrow_scrolls_down_by_one_line/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_down_arrow_scrolls_down_by_one_line/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_down_arrow_scrolls_down_by_one_line/baseline/screen:3')
+  App.screen.check(y, 'ghi', 'baseline/screen:3')
   -- after hitting the down arrow the screen scrolls down by one line
   edit.run_after_keychord(Editor_state, 'down')
-  check_eq(Editor_state.screen_top1.line, 2, 'F - test_down_arrow_scrolls_down_by_one_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 4, 'F - test_down_arrow_scrolls_down_by_one_line/cursor')
+  check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 4, 'cursor')
   y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_down_arrow_scrolls_down_by_one_line/screen:1')
+  App.screen.check(y, 'def', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_down_arrow_scrolls_down_by_one_line/screen:2')
+  App.screen.check(y, 'ghi', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_down_arrow_scrolls_down_by_one_line/screen:3')
+  App.screen.check(y, 'jkl', 'screen:3')
 end
 
 function test_down_arrow_scrolls_down_by_one_screen_line()
-  io.write('\ntest_down_arrow_scrolls_down_by_one_screen_line')
   -- display the first three lines with the cursor on the bottom line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1124,26 +1064,25 @@ function test_down_arrow_scrolls_down_by_one_screen_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_down_arrow_scrolls_down_by_one_screen_line/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_down_arrow_scrolls_down_by_one_screen_line/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi ', 'F - test_down_arrow_scrolls_down_by_one_screen_line/baseline/screen:3')  -- line wrapping includes trailing whitespace
+  App.screen.check(y, 'ghi ', 'baseline/screen:3')  -- line wrapping includes trailing whitespace
   -- after hitting the down arrow the screen scrolls down by one line
   edit.run_after_keychord(Editor_state, 'down')
-  check_eq(Editor_state.screen_top1.line, 2, 'F - test_down_arrow_scrolls_down_by_one_screen_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_down_arrow_scrolls_down_by_one_screen_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 5, 'F - test_down_arrow_scrolls_down_by_one_screen_line/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 5, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_down_arrow_scrolls_down_by_one_screen_line/screen:1')
+  App.screen.check(y, 'def', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi ', 'F - test_down_arrow_scrolls_down_by_one_screen_line/screen:2')
+  App.screen.check(y, 'ghi ', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_down_arrow_scrolls_down_by_one_screen_line/screen:3')
+  App.screen.check(y, 'jkl', 'screen:3')
 end
 
 function test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word()
-  io.write('\ntest_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word')
   -- display the first three lines with the cursor on the bottom line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1154,26 +1093,25 @@ function test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghij', 'F - test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word/baseline/screen:3')
+  App.screen.check(y, 'ghij', 'baseline/screen:3')
   -- after hitting the down arrow the screen scrolls down by one line
   edit.run_after_keychord(Editor_state, 'down')
-  check_eq(Editor_state.screen_top1.line, 2, 'F - test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 5, 'F - test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 5, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word/screen:1')
+  App.screen.check(y, 'def', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghij', 'F - test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word/screen:2')
+  App.screen.check(y, 'ghij', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'kl', 'F - test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word/screen:3')
+  App.screen.check(y, 'kl', 'screen:3')
 end
 
 function test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up()
-  io.write('\ntest_pagedown_followed_by_down_arrow_does_not_scroll_screen_up')
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'ghijkl', 'mno'}
@@ -1183,31 +1121,30 @@ function test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghij', 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/baseline/screen:3')
+  App.screen.check(y, 'ghij', 'baseline/screen:3')
   -- after hitting pagedown the screen scrolls down to start of a long line
   edit.run_after_keychord(Editor_state, 'pagedown')
-  check_eq(Editor_state.screen_top1.line, 3, 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/baseline2/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/baseline2/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/baseline2/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 3, 'baseline2/screen_top')
+  check_eq(Editor_state.cursor1.line, 3, 'baseline2/cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'baseline2/cursor:pos')
   -- after hitting down arrow the screen doesn't scroll down further, and certainly doesn't scroll up
   edit.run_after_keychord(Editor_state, 'down')
-  check_eq(Editor_state.screen_top1.line, 3, 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 5, 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 3, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 5, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'ghij', 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/screen:1')
+  App.screen.check(y, 'ghij', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'kl', 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/screen:2')
+  App.screen.check(y, 'kl', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/screen:3')
+  App.screen.check(y, 'mno', 'screen:3')
 end
 
 function test_up_arrow_moves_cursor()
-  io.write('\ntest_up_arrow_moves_cursor')
   -- display the first 3 lines with the cursor on the bottom line
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1218,26 +1155,25 @@ function test_up_arrow_moves_cursor()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_up_arrow_moves_cursor/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_up_arrow_moves_cursor/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_up_arrow_moves_cursor/baseline/screen:3')
+  App.screen.check(y, 'ghi', 'baseline/screen:3')
   -- after hitting the up arrow the cursor moves up by 1 line
   edit.run_after_keychord(Editor_state, 'up')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_up_arrow_moves_cursor/screen_top')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_up_arrow_moves_cursor/cursor')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor')
   -- the screen is unchanged
   y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_up_arrow_moves_cursor/screen:1')
+  App.screen.check(y, 'abc', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_up_arrow_moves_cursor/screen:2')
+  App.screen.check(y, 'def', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_up_arrow_moves_cursor/screen:3')
+  App.screen.check(y, 'ghi', 'screen:3')
 end
 
 function test_up_arrow_scrolls_up_by_one_line()
-  io.write('\ntest_up_arrow_scrolls_up_by_one_line')
   -- display the lines 2/3/4 with the cursor on line 2
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1248,25 +1184,24 @@ function test_up_arrow_scrolls_up_by_one_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_up_arrow_scrolls_up_by_one_line/baseline/screen:1')
+  App.screen.check(y, 'def', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_up_arrow_scrolls_up_by_one_line/baseline/screen:2')
+  App.screen.check(y, 'ghi', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_up_arrow_scrolls_up_by_one_line/baseline/screen:3')
+  App.screen.check(y, 'jkl', 'baseline/screen:3')
   -- after hitting the up arrow the screen scrolls up by one line
   edit.run_after_keychord(Editor_state, 'up')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_up_arrow_scrolls_up_by_one_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_up_arrow_scrolls_up_by_one_line/cursor')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor')
   y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_up_arrow_scrolls_up_by_one_line/screen:1')
+  App.screen.check(y, 'abc', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_up_arrow_scrolls_up_by_one_line/screen:2')
+  App.screen.check(y, 'def', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_up_arrow_scrolls_up_by_one_line/screen:3')
+  App.screen.check(y, 'ghi', 'screen:3')
 end
 
 function test_up_arrow_scrolls_up_by_one_screen_line()
-  io.write('\ntest_up_arrow_scrolls_up_by_one_screen_line')
   -- display lines starting from second screen line of a line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1277,25 +1212,24 @@ function test_up_arrow_scrolls_up_by_one_screen_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'jkl', 'F - test_up_arrow_scrolls_up_by_one_screen_line/baseline/screen:1')
+  App.screen.check(y, 'jkl', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_up_arrow_scrolls_up_by_one_screen_line/baseline/screen:2')
+  App.screen.check(y, 'mno', 'baseline/screen:2')
   -- after hitting the up arrow the screen scrolls up to first screen line
   edit.run_after_keychord(Editor_state, 'up')
   y = Editor_state.top
-  App.screen.check(y, 'ghi ', 'F - test_up_arrow_scrolls_up_by_one_screen_line/screen:1')
+  App.screen.check(y, 'ghi ', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_up_arrow_scrolls_up_by_one_screen_line/screen:2')
+  App.screen.check(y, 'jkl', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_up_arrow_scrolls_up_by_one_screen_line/screen:3')
-  check_eq(Editor_state.screen_top1.line, 3, 'F - test_up_arrow_scrolls_up_by_one_screen_line/screen_top')
-  check_eq(Editor_state.screen_top1.pos, 1, 'F - test_up_arrow_scrolls_up_by_one_screen_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_up_arrow_scrolls_up_by_one_screen_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_up_arrow_scrolls_up_by_one_screen_line/cursor:pos')
+  App.screen.check(y, 'mno', 'screen:3')
+  check_eq(Editor_state.screen_top1.line, 3, 'screen_top:line')
+  check_eq(Editor_state.screen_top1.pos, 1, 'screen_top:pos')
+  check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
 end
 
 function test_up_arrow_scrolls_up_to_final_screen_line()
-  io.write('\ntest_up_arrow_scrolls_up_to_final_screen_line')
   -- display lines starting just after a long line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1306,27 +1240,26 @@ function test_up_arrow_scrolls_up_to_final_screen_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'ghi', 'F - test_up_arrow_scrolls_up_to_final_screen_line/baseline/screen:1')
+  App.screen.check(y, 'ghi', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_up_arrow_scrolls_up_to_final_screen_line/baseline/screen:2')
+  App.screen.check(y, 'jkl', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_up_arrow_scrolls_up_to_final_screen_line/baseline/screen:3')
+  App.screen.check(y, 'mno', 'baseline/screen:3')
   -- after hitting the up arrow the screen scrolls up to final screen line of previous line
   edit.run_after_keychord(Editor_state, 'up')
   y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_up_arrow_scrolls_up_to_final_screen_line/screen:1')
+  App.screen.check(y, 'def', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_up_arrow_scrolls_up_to_final_screen_line/screen:2')
+  App.screen.check(y, 'ghi', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_up_arrow_scrolls_up_to_final_screen_line/screen:3')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_up_arrow_scrolls_up_to_final_screen_line/screen_top')
-  check_eq(Editor_state.screen_top1.pos, 5, 'F - test_up_arrow_scrolls_up_to_final_screen_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_up_arrow_scrolls_up_to_final_screen_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 5, 'F - test_up_arrow_scrolls_up_to_final_screen_line/cursor:pos')
+  App.screen.check(y, 'jkl', 'screen:3')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top:line')
+  check_eq(Editor_state.screen_top1.pos, 5, 'screen_top:pos')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 5, 'cursor:pos')
 end
 
 function test_up_arrow_scrolls_up_to_empty_line()
-  io.write('\ntest_up_arrow_scrolls_up_to_empty_line')
   -- display a screenful of text with an empty line just above it outside the screen
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1337,25 +1270,24 @@ function test_up_arrow_scrolls_up_to_empty_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_up_arrow_scrolls_up_to_empty_line/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_up_arrow_scrolls_up_to_empty_line/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_up_arrow_scrolls_up_to_empty_line/baseline/screen:3')
+  App.screen.check(y, 'ghi', 'baseline/screen:3')
   -- after hitting the up arrow the screen scrolls up by one line
   edit.run_after_keychord(Editor_state, 'up')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_up_arrow_scrolls_up_to_empty_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_up_arrow_scrolls_up_to_empty_line/cursor')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor')
   y = Editor_state.top
   -- empty first line
   y = y + Editor_state.line_height
-  App.screen.check(y, 'abc', 'F - test_up_arrow_scrolls_up_to_empty_line/screen:2')
+  App.screen.check(y, 'abc', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_up_arrow_scrolls_up_to_empty_line/screen:3')
+  App.screen.check(y, 'def', 'screen:3')
 end
 
 function test_pageup()
-  io.write('\ntest_pageup')
   App.screen.init{width=120, height=45}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'ghi'}
@@ -1366,21 +1298,20 @@ function test_pageup()
   -- initially the last two lines are displayed
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_pageup/baseline/screen:1')
+  App.screen.check(y, 'def', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_pageup/baseline/screen:2')
+  App.screen.check(y, 'ghi', 'baseline/screen:2')
   -- after pageup the cursor goes to first line
   edit.run_after_keychord(Editor_state, 'pageup')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_pageup/screen_top')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_pageup/cursor')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor')
   y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_pageup/screen:1')
+  App.screen.check(y, 'abc', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_pageup/screen:2')
+  App.screen.check(y, 'def', 'screen:2')
 end
 
 function test_pageup_scrolls_up_by_screen_line()
-  io.write('\ntest_pageup_scrolls_up_by_screen_line')
   -- display the first three lines with the cursor on the bottom line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1391,26 +1322,25 @@ function test_pageup_scrolls_up_by_screen_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'ghi', 'F - test_pageup_scrolls_up_by_screen_line/baseline/screen:1')
+  App.screen.check(y, 'ghi', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_pageup_scrolls_up_by_screen_line/baseline/screen:2')
+  App.screen.check(y, 'jkl', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_pageup_scrolls_up_by_screen_line/baseline/screen:3')  -- line wrapping includes trailing whitespace
+  App.screen.check(y, 'mno', 'baseline/screen:3')  -- line wrapping includes trailing whitespace
   -- after hitting the page-up key the screen scrolls up to top
   edit.run_after_keychord(Editor_state, 'pageup')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_pageup_scrolls_up_by_screen_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_pageup_scrolls_up_by_screen_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_pageup_scrolls_up_by_screen_line/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'abc ', 'F - test_pageup_scrolls_up_by_screen_line/screen:1')
+  App.screen.check(y, 'abc ', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_pageup_scrolls_up_by_screen_line/screen:2')
+  App.screen.check(y, 'def', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_pageup_scrolls_up_by_screen_line/screen:3')
+  App.screen.check(y, 'ghi', 'screen:3')
 end
 
 function test_pageup_scrolls_up_from_middle_screen_line()
-  io.write('\ntest_pageup_scrolls_up_from_middle_screen_line')
   -- display a few lines starting from the middle of a line (Editor_state.cursor1.pos > 1)
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1421,24 +1351,23 @@ function test_pageup_scrolls_up_from_middle_screen_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'jkl', 'F - test_pageup_scrolls_up_from_middle_screen_line/baseline/screen:2')
+  App.screen.check(y, 'jkl', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_pageup_scrolls_up_from_middle_screen_line/baseline/screen:3')  -- line wrapping includes trailing whitespace
+  App.screen.check(y, 'mno', 'baseline/screen:3')  -- line wrapping includes trailing whitespace
   -- after hitting the page-up key the screen scrolls up to top
   edit.run_after_keychord(Editor_state, 'pageup')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_pageup_scrolls_up_from_middle_screen_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_pageup_scrolls_up_from_middle_screen_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_pageup_scrolls_up_from_middle_screen_line/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'abc ', 'F - test_pageup_scrolls_up_from_middle_screen_line/screen:1')
+  App.screen.check(y, 'abc ', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_pageup_scrolls_up_from_middle_screen_line/screen:2')
+  App.screen.check(y, 'def', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi ', 'F - test_pageup_scrolls_up_from_middle_screen_line/screen:3')
+  App.screen.check(y, 'ghi ', 'screen:3')
 end
 
 function test_enter_on_bottom_line_scrolls_down()
-  io.write('\ntest_enter_on_bottom_line_scrolls_down')
   -- display a few lines with cursor on bottom line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1449,26 +1378,25 @@ function test_enter_on_bottom_line_scrolls_down()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_enter_on_bottom_line_scrolls_down/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_enter_on_bottom_line_scrolls_down/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_enter_on_bottom_line_scrolls_down/baseline/screen:3')
+  App.screen.check(y, 'ghi', 'baseline/screen:3')
   -- after hitting the enter key the screen scrolls down
   edit.run_after_keychord(Editor_state, 'return')
-  check_eq(Editor_state.screen_top1.line, 2, 'F - test_enter_on_bottom_line_scrolls_down/screen_top')
-  check_eq(Editor_state.cursor1.line, 4, 'F - test_enter_on_bottom_line_scrolls_down/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_enter_on_bottom_line_scrolls_down/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 4, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_enter_on_bottom_line_scrolls_down/screen:1')
+  App.screen.check(y, 'def', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'g', 'F - test_enter_on_bottom_line_scrolls_down/screen:2')
+  App.screen.check(y, 'g', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'hi', 'F - test_enter_on_bottom_line_scrolls_down/screen:3')
+  App.screen.check(y, 'hi', 'screen:3')
 end
 
 function test_enter_on_final_line_avoids_scrolling_down_when_not_at_bottom()
-  io.write('\ntest_enter_on_final_line_avoids_scrolling_down_when_not_at_bottom')
   -- display just the bottom line on screen
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1479,20 +1407,19 @@ function test_enter_on_final_line_avoids_scrolling_down_when_not_at_bottom()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'jkl', 'F - test_enter_on_final_line_avoids_scrolling_down_when_not_at_bottom/baseline/screen:1')
+  App.screen.check(y, 'jkl', 'baseline/screen:1')
   -- after hitting the enter key the screen does not scroll down
   edit.run_after_keychord(Editor_state, 'return')
-  check_eq(Editor_state.screen_top1.line, 4, 'F - test_enter_on_final_line_avoids_scrolling_down_when_not_at_bottom/screen_top')
-  check_eq(Editor_state.cursor1.line, 5, 'F - test_enter_on_final_line_avoids_scrolling_down_when_not_at_bottom/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_enter_on_final_line_avoids_scrolling_down_when_not_at_bottom/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 4, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 5, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'j', 'F - test_enter_on_final_line_avoids_scrolling_down_when_not_at_bottom/screen:1')
+  App.screen.check(y, 'j', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'kl', 'F - test_enter_on_final_line_avoids_scrolling_down_when_not_at_bottom/screen:2')
+  App.screen.check(y, 'kl', 'screen:2')
 end
 
 function test_inserting_text_on_final_line_avoids_scrolling_down_when_not_at_bottom()
-  io.write('\ntest_inserting_text_on_final_line_avoids_scrolling_down_when_not_at_bottom')
   -- display just an empty bottom line on screen
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1504,15 +1431,14 @@ function test_inserting_text_on_final_line_avoids_scrolling_down_when_not_at_bot
   edit.draw(Editor_state)
   -- after hitting the inserting_text key the screen does not scroll down
   edit.run_after_text_input(Editor_state, 'a')
-  check_eq(Editor_state.screen_top1.line, 2, 'F - test_inserting_text_on_final_line_avoids_scrolling_down_when_not_at_bottom/screen_top')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_inserting_text_on_final_line_avoids_scrolling_down_when_not_at_bottom/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 2, 'F - test_inserting_text_on_final_line_avoids_scrolling_down_when_not_at_bottom/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
   local y = Editor_state.top
-  App.screen.check(y, 'a', 'F - test_inserting_text_on_final_line_avoids_scrolling_down_when_not_at_bottom/screen:1')
+  App.screen.check(y, 'a', 'screen:1')
 end
 
 function test_typing_on_bottom_line_scrolls_down()
-  io.write('\ntest_typing_on_bottom_line_scrolls_down')
   -- display a few lines with cursor on bottom line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1523,28 +1449,27 @@ function test_typing_on_bottom_line_scrolls_down()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_typing_on_bottom_line_scrolls_down/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_typing_on_bottom_line_scrolls_down/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_typing_on_bottom_line_scrolls_down/baseline/screen:3')
+  App.screen.check(y, 'ghi', 'baseline/screen:3')
   -- after typing something the line wraps and the screen scrolls down
   edit.run_after_text_input(Editor_state, 'j')
   edit.run_after_text_input(Editor_state, 'k')
   edit.run_after_text_input(Editor_state, 'l')
-  check_eq(Editor_state.screen_top1.line, 2, 'F - test_typing_on_bottom_line_scrolls_down/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_typing_on_bottom_line_scrolls_down/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 7, 'F - test_typing_on_bottom_line_scrolls_down/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 7, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_typing_on_bottom_line_scrolls_down/screen:1')
+  App.screen.check(y, 'def', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghij', 'F - test_typing_on_bottom_line_scrolls_down/screen:2')
+  App.screen.check(y, 'ghij', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'kl', 'F - test_typing_on_bottom_line_scrolls_down/screen:3')
+  App.screen.check(y, 'kl', 'screen:3')
 end
 
 function test_left_arrow_scrolls_up_in_wrapped_line()
-  io.write('\ntest_left_arrow_scrolls_up_in_wrapped_line')
   -- display lines starting from second screen line of a line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1556,25 +1481,24 @@ function test_left_arrow_scrolls_up_in_wrapped_line()
   Editor_state.cursor1 = {line=3, pos=5}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'jkl', 'F - test_left_arrow_scrolls_up_in_wrapped_line/baseline/screen:1')
+  App.screen.check(y, 'jkl', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_left_arrow_scrolls_up_in_wrapped_line/baseline/screen:2')
+  App.screen.check(y, 'mno', 'baseline/screen:2')
   -- after hitting the left arrow the screen scrolls up to first screen line
   edit.run_after_keychord(Editor_state, 'left')
   y = Editor_state.top
-  App.screen.check(y, 'ghi ', 'F - test_left_arrow_scrolls_up_in_wrapped_line/screen:1')
+  App.screen.check(y, 'ghi ', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_left_arrow_scrolls_up_in_wrapped_line/screen:2')
+  App.screen.check(y, 'jkl', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_left_arrow_scrolls_up_in_wrapped_line/screen:3')
-  check_eq(Editor_state.screen_top1.line, 3, 'F - test_left_arrow_scrolls_up_in_wrapped_line/screen_top')
-  check_eq(Editor_state.screen_top1.pos, 1, 'F - test_left_arrow_scrolls_up_in_wrapped_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_left_arrow_scrolls_up_in_wrapped_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 4, 'F - test_left_arrow_scrolls_up_in_wrapped_line/cursor:pos')
+  App.screen.check(y, 'mno', 'screen:3')
+  check_eq(Editor_state.screen_top1.line, 3, 'screen_top:line')
+  check_eq(Editor_state.screen_top1.pos, 1, 'screen_top:pos')
+  check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 4, 'cursor:pos')
 end
 
 function test_right_arrow_scrolls_down_in_wrapped_line()
-  io.write('\ntest_right_arrow_scrolls_down_in_wrapped_line')
   -- display the first three lines with the cursor on the bottom line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1586,26 +1510,25 @@ function test_right_arrow_scrolls_down_in_wrapped_line()
   Editor_state.cursor1 = {line=3, pos=5}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_right_arrow_scrolls_down_in_wrapped_line/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_right_arrow_scrolls_down_in_wrapped_line/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi ', 'F - test_right_arrow_scrolls_down_in_wrapped_line/baseline/screen:3')  -- line wrapping includes trailing whitespace
+  App.screen.check(y, 'ghi ', 'baseline/screen:3')  -- line wrapping includes trailing whitespace
   -- after hitting the right arrow the screen scrolls down by one line
   edit.run_after_keychord(Editor_state, 'right')
-  check_eq(Editor_state.screen_top1.line, 2, 'F - test_right_arrow_scrolls_down_in_wrapped_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_right_arrow_scrolls_down_in_wrapped_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 6, 'F - test_right_arrow_scrolls_down_in_wrapped_line/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 6, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_right_arrow_scrolls_down_in_wrapped_line/screen:1')
+  App.screen.check(y, 'def', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi ', 'F - test_right_arrow_scrolls_down_in_wrapped_line/screen:2')
+  App.screen.check(y, 'ghi ', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_right_arrow_scrolls_down_in_wrapped_line/screen:3')
+  App.screen.check(y, 'jkl', 'screen:3')
 end
 
 function test_home_scrolls_up_in_wrapped_line()
-  io.write('\ntest_home_scrolls_up_in_wrapped_line')
   -- display lines starting from second screen line of a line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1617,25 +1540,24 @@ function test_home_scrolls_up_in_wrapped_line()
   Editor_state.cursor1 = {line=3, pos=5}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'jkl', 'F - test_home_scrolls_up_in_wrapped_line/baseline/screen:1')
+  App.screen.check(y, 'jkl', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_home_scrolls_up_in_wrapped_line/baseline/screen:2')
+  App.screen.check(y, 'mno', 'baseline/screen:2')
   -- after hitting home the screen scrolls up to first screen line
   edit.run_after_keychord(Editor_state, 'home')
   y = Editor_state.top
-  App.screen.check(y, 'ghi ', 'F - test_home_scrolls_up_in_wrapped_line/screen:1')
+  App.screen.check(y, 'ghi ', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_home_scrolls_up_in_wrapped_line/screen:2')
+  App.screen.check(y, 'jkl', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_home_scrolls_up_in_wrapped_line/screen:3')
-  check_eq(Editor_state.screen_top1.line, 3, 'F - test_home_scrolls_up_in_wrapped_line/screen_top')
-  check_eq(Editor_state.screen_top1.pos, 1, 'F - test_home_scrolls_up_in_wrapped_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_home_scrolls_up_in_wrapped_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_home_scrolls_up_in_wrapped_line/cursor:pos')
+  App.screen.check(y, 'mno', 'screen:3')
+  check_eq(Editor_state.screen_top1.line, 3, 'screen_top:line')
+  check_eq(Editor_state.screen_top1.pos, 1, 'screen_top:pos')
+  check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
 end
 
 function test_end_scrolls_down_in_wrapped_line()
-  io.write('\ntest_end_scrolls_down_in_wrapped_line')
   -- display the first three lines with the cursor on the bottom line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1647,27 +1569,26 @@ function test_end_scrolls_down_in_wrapped_line()
   Editor_state.cursor1 = {line=3, pos=5}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_end_scrolls_down_in_wrapped_line/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_end_scrolls_down_in_wrapped_line/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi ', 'F - test_end_scrolls_down_in_wrapped_line/baseline/screen:3')  -- line wrapping includes trailing whitespace
+  App.screen.check(y, 'ghi ', 'baseline/screen:3')  -- line wrapping includes trailing whitespace
   -- after hitting end the screen scrolls down by one line
   edit.run_after_keychord(Editor_state, 'end')
-  check_eq(Editor_state.screen_top1.line, 2, 'F - test_end_scrolls_down_in_wrapped_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_end_scrolls_down_in_wrapped_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 8, 'F - test_end_scrolls_down_in_wrapped_line/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 8, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_end_scrolls_down_in_wrapped_line/screen:1')
+  App.screen.check(y, 'def', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi ', 'F - test_end_scrolls_down_in_wrapped_line/screen:2')
+  App.screen.check(y, 'ghi ', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_end_scrolls_down_in_wrapped_line/screen:3')
+  App.screen.check(y, 'jkl', 'screen:3')
 end
 
 function test_position_cursor_on_recently_edited_wrapping_line()
   -- draw a line wrapping over 2 screen lines
-  io.write('\ntest_position_cursor_on_recently_edited_wrapping_line')
   App.screen.init{width=100, height=200}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc def ghi jkl mno pqr ', 'xyz'}
@@ -1677,31 +1598,30 @@ function test_position_cursor_on_recently_edited_wrapping_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc def ghi ', 'F - test_position_cursor_on_recently_edited_wrapping_line/baseline1/screen:1')
+  App.screen.check(y, 'abc def ghi ', 'baseline1/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl mno pqr ', 'F - test_position_cursor_on_recently_edited_wrapping_line/baseline1/screen:2')
+  App.screen.check(y, 'jkl mno pqr ', 'baseline1/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'xyz', 'F - test_position_cursor_on_recently_edited_wrapping_line/baseline1/screen:3')
+  App.screen.check(y, 'xyz', 'baseline1/screen:3')
   -- add to the line until it's wrapping over 3 screen lines
   edit.run_after_text_input(Editor_state, 's')
   edit.run_after_text_input(Editor_state, 't')
   edit.run_after_text_input(Editor_state, 'u')
-  check_eq(Editor_state.cursor1.pos, 28, 'F - test_position_cursor_on_recently_edited_wrapping_line/cursor:pos')
+  check_eq(Editor_state.cursor1.pos, 28, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'abc def ghi ', 'F - test_position_cursor_on_recently_edited_wrapping_line/baseline2/screen:1')
+  App.screen.check(y, 'abc def ghi ', 'baseline2/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl mno pqr ', 'F - test_position_cursor_on_recently_edited_wrapping_line/baseline2/screen:2')
+  App.screen.check(y, 'jkl mno pqr ', 'baseline2/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'stu', 'F - test_position_cursor_on_recently_edited_wrapping_line/baseline2/screen:3')
+  App.screen.check(y, 'stu', 'baseline2/screen:3')
   -- try to move the cursor earlier in the third screen line by clicking the mouse
   edit.run_after_mouse_release(Editor_state, Editor_state.left+8,Editor_state.top+Editor_state.line_height*2+5, 1)
   -- cursor should move
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_position_cursor_on_recently_edited_wrapping_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 26, 'F - test_position_cursor_on_recently_edited_wrapping_line/cursor:pos')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 26, 'cursor:pos')
 end
 
 function test_backspace_can_scroll_up()
-  io.write('\ntest_backspace_can_scroll_up')
   -- display the lines 2/3/4 with the cursor on line 2
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1712,25 +1632,24 @@ function test_backspace_can_scroll_up()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_backspace_can_scroll_up/baseline/screen:1')
+  App.screen.check(y, 'def', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_backspace_can_scroll_up/baseline/screen:2')
+  App.screen.check(y, 'ghi', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_backspace_can_scroll_up/baseline/screen:3')
+  App.screen.check(y, 'jkl', 'baseline/screen:3')
   -- after hitting backspace the screen scrolls up by one line
   edit.run_after_keychord(Editor_state, 'backspace')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_backspace_can_scroll_up/screen_top')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_backspace_can_scroll_up/cursor')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor')
   y = Editor_state.top
-  App.screen.check(y, 'abcdef', 'F - test_backspace_can_scroll_up/screen:1')
+  App.screen.check(y, 'abcdef', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_backspace_can_scroll_up/screen:2')
+  App.screen.check(y, 'ghi', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_backspace_can_scroll_up/screen:3')
+  App.screen.check(y, 'jkl', 'screen:3')
 end
 
 function test_backspace_can_scroll_up_screen_line()
-  io.write('\ntest_backspace_can_scroll_up_screen_line')
   -- display lines starting from second screen line of a line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1741,25 +1660,24 @@ function test_backspace_can_scroll_up_screen_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'jkl', 'F - test_backspace_can_scroll_up_screen_line/baseline/screen:1')
+  App.screen.check(y, 'jkl', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_backspace_can_scroll_up_screen_line/baseline/screen:2')
+  App.screen.check(y, 'mno', 'baseline/screen:2')
   -- after hitting backspace the screen scrolls up by one screen line
   edit.run_after_keychord(Editor_state, 'backspace')
   y = Editor_state.top
-  App.screen.check(y, 'ghij', 'F - test_backspace_can_scroll_up_screen_line/screen:1')
+  App.screen.check(y, 'ghij', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'kl', 'F - test_backspace_can_scroll_up_screen_line/screen:2')
+  App.screen.check(y, 'kl', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_backspace_can_scroll_up_screen_line/screen:3')
-  check_eq(Editor_state.screen_top1.line, 3, 'F - test_backspace_can_scroll_up_screen_line/screen_top')
-  check_eq(Editor_state.screen_top1.pos, 1, 'F - test_backspace_can_scroll_up_screen_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_backspace_can_scroll_up_screen_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 4, 'F - test_backspace_can_scroll_up_screen_line/cursor:pos')
+  App.screen.check(y, 'mno', 'screen:3')
+  check_eq(Editor_state.screen_top1.line, 3, 'screen_top:line')
+  check_eq(Editor_state.screen_top1.pos, 1, 'screen_top:pos')
+  check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 4, 'cursor:pos')
 end
 
 function test_backspace_past_line_boundary()
-  io.write('\ntest_backspace_past_line_boundary')
   -- position cursor at start of a (non-first) line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1768,14 +1686,13 @@ function test_backspace_past_line_boundary()
   Editor_state.cursor1 = {line=2, pos=1}
   -- backspace joins with previous line
   edit.run_after_keychord(Editor_state, 'backspace')
-  check_eq(Editor_state.lines[1].data, 'abcdef', "F - test_backspace_past_line_boundary")
+  check_eq(Editor_state.lines[1].data, 'abcdef', 'check')
 end
 
 -- some tests for operating over selections created using Shift- chords
 -- we're just testing delete_selection, and it works the same for all keys
 
 function test_backspace_over_selection()
-  io.write('\ntest_backspace_over_selection')
   -- select just one character within a line with cursor before selection
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1785,16 +1702,15 @@ function test_backspace_over_selection()
   Editor_state.selection1 = {line=1, pos=2}
   -- backspace deletes the selected character, even though it's after the cursor
   edit.run_after_keychord(Editor_state, 'backspace')
-  check_eq(Editor_state.lines[1].data, 'bc', "F - test_backspace_over_selection/data")
+  check_eq(Editor_state.lines[1].data, 'bc', 'data')
   -- cursor (remains) at start of selection
-  check_eq(Editor_state.cursor1.line, 1, "F - test_backspace_over_selection/cursor:line")
-  check_eq(Editor_state.cursor1.pos, 1, "F - test_backspace_over_selection/cursor:pos")
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
   -- selection is cleared
-  check_nil(Editor_state.selection1.line, "F - test_backspace_over_selection/selection")
+  check_nil(Editor_state.selection1.line, 'selection')
 end
 
 function test_backspace_over_selection_reverse()
-  io.write('\ntest_backspace_over_selection_reverse')
   -- select just one character within a line with cursor after selection
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1804,16 +1720,15 @@ function test_backspace_over_selection_reverse()
   Editor_state.selection1 = {line=1, pos=1}
   -- backspace deletes the selected character
   edit.run_after_keychord(Editor_state, 'backspace')
-  check_eq(Editor_state.lines[1].data, 'bc', "F - test_backspace_over_selection_reverse/data")
+  check_eq(Editor_state.lines[1].data, 'bc', 'data')
   -- cursor moves to start of selection
-  check_eq(Editor_state.cursor1.line, 1, "F - test_backspace_over_selection_reverse/cursor:line")
-  check_eq(Editor_state.cursor1.pos, 1, "F - test_backspace_over_selection_reverse/cursor:pos")
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
   -- selection is cleared
-  check_nil(Editor_state.selection1.line, "F - test_backspace_over_selection_reverse/selection")
+  check_nil(Editor_state.selection1.line, 'selection')
 end
 
 function test_backspace_over_multiple_lines()
-  io.write('\ntest_backspace_over_multiple_lines')
   -- select just one character within a line with cursor after selection
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1823,17 +1738,16 @@ function test_backspace_over_multiple_lines()
   Editor_state.selection1 = {line=4, pos=2}
   -- backspace deletes the region and joins the remaining portions of lines on either side
   edit.run_after_keychord(Editor_state, 'backspace')
-  check_eq(Editor_state.lines[1].data, 'akl', "F - test_backspace_over_multiple_lines/data:1")
-  check_eq(Editor_state.lines[2].data, 'mno', "F - test_backspace_over_multiple_lines/data:2")
+  check_eq(Editor_state.lines[1].data, 'akl', 'data:1')
+  check_eq(Editor_state.lines[2].data, 'mno', 'data:2')
   -- cursor remains at start of selection
-  check_eq(Editor_state.cursor1.line, 1, "F - test_backspace_over_multiple_lines/cursor:line")
-  check_eq(Editor_state.cursor1.pos, 2, "F - test_backspace_over_multiple_lines/cursor:pos")
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
   -- selection is cleared
-  check_nil(Editor_state.selection1.line, "F - test_backspace_over_multiple_lines/selection")
+  check_nil(Editor_state.selection1.line, 'selection')
 end
 
 function test_backspace_to_end_of_line()
-  io.write('\ntest_backspace_to_end_of_line')
   -- select region from cursor to end of line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1843,17 +1757,16 @@ function test_backspace_to_end_of_line()
   Editor_state.selection1 = {line=1, pos=4}
   -- backspace deletes rest of line without joining to any other line
   edit.run_after_keychord(Editor_state, 'backspace')
-  check_eq(Editor_state.lines[1].data, 'a', "F - test_backspace_to_start_of_line/data:1")
-  check_eq(Editor_state.lines[2].data, 'def', "F - test_backspace_to_start_of_line/data:2")
+  check_eq(Editor_state.lines[1].data, 'a', 'data:1')
+  check_eq(Editor_state.lines[2].data, 'def', 'data:2')
   -- cursor remains at start of selection
-  check_eq(Editor_state.cursor1.line, 1, "F - test_backspace_to_start_of_line/cursor:line")
-  check_eq(Editor_state.cursor1.pos, 2, "F - test_backspace_to_start_of_line/cursor:pos")
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
   -- selection is cleared
-  check_nil(Editor_state.selection1.line, "F - test_backspace_to_start_of_line/selection")
+  check_nil(Editor_state.selection1.line, 'selection')
 end
 
 function test_backspace_to_start_of_line()
-  io.write('\ntest_backspace_to_start_of_line')
   -- select region from cursor to start of line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1863,17 +1776,16 @@ function test_backspace_to_start_of_line()
   Editor_state.selection1 = {line=2, pos=3}
   -- backspace deletes beginning of line without joining to any other line
   edit.run_after_keychord(Editor_state, 'backspace')
-  check_eq(Editor_state.lines[1].data, 'abc', "F - test_backspace_to_start_of_line/data:1")
-  check_eq(Editor_state.lines[2].data, 'f', "F - test_backspace_to_start_of_line/data:2")
+  check_eq(Editor_state.lines[1].data, 'abc', 'data:1')
+  check_eq(Editor_state.lines[2].data, 'f', 'data:2')
   -- cursor remains at start of selection
-  check_eq(Editor_state.cursor1.line, 2, "F - test_backspace_to_start_of_line/cursor:line")
-  check_eq(Editor_state.cursor1.pos, 1, "F - test_backspace_to_start_of_line/cursor:pos")
+  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
   -- selection is cleared
-  check_nil(Editor_state.selection1.line, "F - test_backspace_to_start_of_line/selection")
+  check_nil(Editor_state.selection1.line, 'selection')
 end
 
 function test_undo_insert_text()
-  io.write('\ntest_undo_insert_text')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'xyz'}
@@ -1884,32 +1796,31 @@ function test_undo_insert_text()
   -- insert a character
   edit.draw(Editor_state)
   edit.run_after_text_input(Editor_state, 'g')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_undo_insert_text/baseline/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 5, 'F - test_undo_insert_text/baseline/cursor:pos')
-  check_nil(Editor_state.selection1.line, 'F - test_undo_insert_text/baseline/selection:line')
-  check_nil(Editor_state.selection1.pos, 'F - test_undo_insert_text/baseline/selection:pos')
+  check_eq(Editor_state.cursor1.line, 2, 'baseline/cursor:line')
+  check_eq(Editor_state.cursor1.pos, 5, 'baseline/cursor:pos')
+  check_nil(Editor_state.selection1.line, 'baseline/selection:line')
+  check_nil(Editor_state.selection1.pos, 'baseline/selection:pos')
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_undo_insert_text/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'defg', 'F - test_undo_insert_text/baseline/screen:2')
+  App.screen.check(y, 'defg', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'xyz', 'F - test_undo_insert_text/baseline/screen:3')
+  App.screen.check(y, 'xyz', 'baseline/screen:3')
   -- undo
   edit.run_after_keychord(Editor_state, 'C-z')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_undo_insert_text/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 4, 'F - test_undo_insert_text/cursor:pos')
-  check_nil(Editor_state.selection1.line, 'F - test_undo_insert_text/selection:line')
-  check_nil(Editor_state.selection1.pos, 'F - test_undo_insert_text/selection:pos')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 4, 'cursor:pos')
+  check_nil(Editor_state.selection1.line, 'selection:line')
+  check_nil(Editor_state.selection1.pos, 'selection:pos')
   y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_undo_insert_text/screen:1')
+  App.screen.check(y, 'abc', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_undo_insert_text/screen:2')
+  App.screen.check(y, 'def', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'xyz', 'F - test_undo_insert_text/screen:3')
+  App.screen.check(y, 'xyz', 'screen:3')
 end
 
 function test_undo_delete_text()
-  io.write('\ntest_undo_delete_text')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'defg', 'xyz'}
@@ -1919,35 +1830,34 @@ function test_undo_delete_text()
   Editor_state.screen_bottom1 = {}
   -- delete a character
   edit.run_after_keychord(Editor_state, 'backspace')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_undo_delete_text/baseline/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 4, 'F - test_undo_delete_text/baseline/cursor:pos')
-  check_nil(Editor_state.selection1.line, 'F - test_undo_delete_text/baseline/selection:line')
-  check_nil(Editor_state.selection1.pos, 'F - test_undo_delete_text/baseline/selection:pos')
+  check_eq(Editor_state.cursor1.line, 2, 'baseline/cursor:line')
+  check_eq(Editor_state.cursor1.pos, 4, 'baseline/cursor:pos')
+  check_nil(Editor_state.selection1.line, 'baseline/selection:line')
+  check_nil(Editor_state.selection1.pos, 'baseline/selection:pos')
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_undo_delete_text/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_undo_delete_text/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'xyz', 'F - test_undo_delete_text/baseline/screen:3')
+  App.screen.check(y, 'xyz', 'baseline/screen:3')
   -- undo
 --?   -- after undo, the backspaced key is selected
   edit.run_after_keychord(Editor_state, 'C-z')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_undo_delete_text/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 5, 'F - test_undo_delete_text/cursor:pos')
-  check_nil(Editor_state.selection1.line, 'F - test_undo_delete_text/selection:line')
-  check_nil(Editor_state.selection1.pos, 'F - test_undo_delete_text/selection:pos')
---?   check_eq(Editor_state.selection1.line, 2, 'F - test_undo_delete_text/selection:line')
---?   check_eq(Editor_state.selection1.pos, 4, 'F - test_undo_delete_text/selection:pos')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 5, 'cursor:pos')
+  check_nil(Editor_state.selection1.line, 'selection:line')
+  check_nil(Editor_state.selection1.pos, 'selection:pos')
+--?   check_eq(Editor_state.selection1.line, 2, 'selection:line')
+--?   check_eq(Editor_state.selection1.pos, 4, 'selection:pos')
   y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_undo_delete_text/screen:1')
+  App.screen.check(y, 'abc', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'defg', 'F - test_undo_delete_text/screen:2')
+  App.screen.check(y, 'defg', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'xyz', 'F - test_undo_delete_text/screen:3')
+  App.screen.check(y, 'xyz', 'screen:3')
 end
 
 function test_undo_restores_selection()
-  io.write('\ntest_undo_restores_selection')
   -- display a line of text with some part selected
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -1960,18 +1870,17 @@ function test_undo_restores_selection()
   edit.draw(Editor_state)
   -- delete selected text
   edit.run_after_text_input(Editor_state, 'x')
-  check_eq(Editor_state.lines[1].data, 'xbc', 'F - test_undo_restores_selection/baseline')
-  check_nil(Editor_state.selection1.line, 'F - test_undo_restores_selection/baseline:selection')
+  check_eq(Editor_state.lines[1].data, 'xbc', 'baseline')
+  check_nil(Editor_state.selection1.line, 'baseline:selection')
   -- undo
   edit.run_after_keychord(Editor_state, 'C-z')
   edit.run_after_keychord(Editor_state, 'C-z')
   -- selection is restored
-  check_eq(Editor_state.selection1.line, 1, 'F - test_undo_restores_selection/line')
-  check_eq(Editor_state.selection1.pos, 2, 'F - test_undo_restores_selection/pos')
+  check_eq(Editor_state.selection1.line, 1, 'line')
+  check_eq(Editor_state.selection1.pos, 2, 'pos')
 end
 
 function test_search()
-  io.write('\ntest_search')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'```lines', '```', 'def', 'ghi', 'deg'}
@@ -1984,8 +1893,8 @@ function test_search()
   edit.run_after_keychord(Editor_state, 'C-f')
   edit.run_after_text_input(Editor_state, 'd')
   edit.run_after_keychord(Editor_state, 'return')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_search/1/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_search/1/cursor:pos')
+  check_eq(Editor_state.cursor1.line, 2, '1/cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, '1/cursor:pos')
   -- reset cursor
   Editor_state.cursor1 = {line=1, pos=1}
   Editor_state.screen_top1 = {line=1, pos=1}
@@ -1994,12 +1903,11 @@ function test_search()
   edit.run_after_text_input(Editor_state, 'de')
   edit.run_after_keychord(Editor_state, 'down')
   edit.run_after_keychord(Editor_state, 'return')
-  check_eq(Editor_state.cursor1.line, 4, 'F - test_search/2/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_search/2/cursor:pos')
+  check_eq(Editor_state.cursor1.line, 4, '2/cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, '2/cursor:pos')
 end
 
 function test_search_upwards()
-  io.write('\ntest_search_upwards')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc abd'}
@@ -2013,12 +1921,11 @@ function test_search_upwards()
   edit.run_after_text_input(Editor_state, 'a')
   -- search for previous occurrence
   edit.run_after_keychord(Editor_state, 'up')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_search_upwards/2/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_search_upwards/2/cursor:pos')
+  check_eq(Editor_state.cursor1.line, 1, '2/cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, '2/cursor:pos')
 end
 
 function test_search_wrap()
-  io.write('\ntest_search_wrap')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc'}
@@ -2032,12 +1939,11 @@ function test_search_wrap()
   edit.run_after_text_input(Editor_state, 'a')
   edit.run_after_keychord(Editor_state, 'return')
   -- cursor wraps
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_search_wrap/1/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_search_wrap/1/cursor:pos')
+  check_eq(Editor_state.cursor1.line, 1, '1/cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, '1/cursor:pos')
 end
 
 function test_search_wrap_upwards()
-  io.write('\ntest_search_wrap_upwards')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc abd'}
@@ -2051,6 +1957,6 @@ function test_search_wrap_upwards()
   edit.run_after_text_input(Editor_state, 'a')
   edit.run_after_keychord(Editor_state, 'up')
   -- cursor wraps
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_search_wrap_upwards/1/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 5, 'F - test_search_wrap_upwards/1/cursor:pos')
+  check_eq(Editor_state.cursor1.line, 1, '1/cursor:line')
+  check_eq(Editor_state.cursor1.pos, 5, '1/cursor:pos')
 end
diff --git a/test.lua b/test.lua
index ab890b8..cc94d94 100644
--- a/test.lua
+++ b/test.lua
@@ -1,29 +1,20 @@
 -- Some primitives for tests.
---
--- Success indicators go to the terminal; failures go to the window.
--- I don't know what I am doing.
 
 function check(x, msg)
-  if x then
-    io.write('.')
-  else
+  if not x then
     error(msg)
   end
 end
 
 function check_nil(x, msg)
-  if x == nil then
-    io.write('.')
-  else
+  if x ~= nil then
     error(msg..'; should be nil but got "'..x..'"')
   end
 end
 
 function check_eq(x, expected, msg)
-  if eq(x, expected) then
-    io.write('.')
-  else
-    error(msg..'; got "'..x..'"')
+  if not eq(x, expected) then
+    error(msg..'; should be "'..expected..'" but got "'..x..'"')
   end
 end
 
diff --git a/text_tests.lua b/text_tests.lua
index d94b1ec..6e6318d 100644
--- a/text_tests.lua
+++ b/text_tests.lua
@@ -1,21 +1,19 @@
 -- major tests for text editing flows
 
 function test_initial_state()
-  io.write('\ntest_initial_state')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{}
   Text.redraw_all(Editor_state)
   edit.draw(Editor_state)
-  check_eq(#Editor_state.lines, 1, 'F - test_initial_state/#lines')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_initial_state/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_initial_state/cursor:pos')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_initial_state/screen_top:line')
-  check_eq(Editor_state.screen_top1.pos, 1, 'F - test_initial_state/screen_top:pos')
+  check_eq(#Editor_state.lines, 1, '#lines')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top:line')
+  check_eq(Editor_state.screen_top1.pos, 1, 'screen_top:pos')
 end
 
 function test_backspace_from_start_of_final_line()
-  io.write('\ntest_backspace_from_start_of_final_line')
   -- display final line of text with cursor at start of it
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
@@ -25,13 +23,12 @@ function test_backspace_from_start_of_final_line()
   Text.redraw_all(Editor_state)
   -- backspace scrolls up
   edit.run_after_keychord(Editor_state, 'backspace')
-  check_eq(#Editor_state.lines, 1, 'F - test_backspace_from_start_of_final_line/#lines')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_backspace_from_start_of_final_line/cursor')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_backspace_from_start_of_final_line/screen_top')
+  check_eq(#Editor_state.lines, 1, '#lines')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
 end
 
 function test_insert_first_character()
-  io.write('\ntest_insert_first_character')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{}
@@ -39,11 +36,10 @@ function test_insert_first_character()
   edit.draw(Editor_state)
   edit.run_after_text_input(Editor_state, 'a')
   local y = Editor_state.top
-  App.screen.check(y, 'a', 'F - test_insert_first_character/screen:1')
+  App.screen.check(y, 'a', 'screen:1')
 end
 
 function test_press_ctrl()
-  io.write('\ntest_press_ctrl')
   -- press ctrl while the cursor is on text
   App.screen.init{width=50, height=80}
   Editor_state = edit.initialize_test_state()
@@ -56,7 +52,6 @@ function test_press_ctrl()
 end
 
 function test_move_left()
-  io.write('\ntest_move_left')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'a'}
@@ -64,11 +59,10 @@ function test_move_left()
   Editor_state.cursor1 = {line=1, pos=2}
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'left')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_move_left')
+  check_eq(Editor_state.cursor1.pos, 1, 'check')
 end
 
 function test_move_right()
-  io.write('\ntest_move_right')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'a'}
@@ -76,11 +70,10 @@ function test_move_right()
   Editor_state.cursor1 = {line=1, pos=1}
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'right')
-  check_eq(Editor_state.cursor1.pos, 2, 'F - test_move_right')
+  check_eq(Editor_state.cursor1.pos, 2, 'check')
 end
 
 function test_move_left_to_previous_line()
-  io.write('\ntest_move_left_to_previous_line')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def'}
@@ -88,12 +81,11 @@ function test_move_left_to_previous_line()
   Editor_state.cursor1 = {line=2, pos=1}
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'left')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_move_left_to_previous_line/line')
-  check_eq(Editor_state.cursor1.pos, 4, 'F - test_move_left_to_previous_line/pos')  -- past end of line
+  check_eq(Editor_state.cursor1.line, 1, 'line')
+  check_eq(Editor_state.cursor1.pos, 4, 'pos')  -- past end of line
 end
 
 function test_move_right_to_next_line()
-  io.write('\ntest_move_right_to_next_line')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def'}
@@ -101,12 +93,11 @@ function test_move_right_to_next_line()
   Editor_state.cursor1 = {line=1, pos=4}  -- past end of line
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'right')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_move_right_to_next_line/line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_move_right_to_next_line/pos')
+  check_eq(Editor_state.cursor1.line, 2, 'line')
+  check_eq(Editor_state.cursor1.pos, 1, 'pos')
 end
 
 function test_move_to_start_of_word()
-  io.write('\ntest_move_to_start_of_word')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc'}
@@ -114,11 +105,10 @@ function test_move_to_start_of_word()
   Editor_state.cursor1 = {line=1, pos=3}
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-left')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_move_to_start_of_word')
+  check_eq(Editor_state.cursor1.pos, 1, 'check')
 end
 
 function test_move_to_start_of_previous_word()
-  io.write('\ntest_move_to_start_of_previous_word')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc def'}
@@ -126,11 +116,10 @@ function test_move_to_start_of_previous_word()
   Editor_state.cursor1 = {line=1, pos=4}  -- at the space between words
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-left')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_move_to_start_of_previous_word')
+  check_eq(Editor_state.cursor1.pos, 1, 'check')
 end
 
 function test_skip_to_previous_word()
-  io.write('\ntest_skip_to_previous_word')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc def'}
@@ -138,11 +127,10 @@ function test_skip_to_previous_word()
   Editor_state.cursor1 = {line=1, pos=5}  -- at the start of second word
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-left')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_skip_to_previous_word')
+  check_eq(Editor_state.cursor1.pos, 1, 'check')
 end
 
 function test_skip_past_tab_to_previous_word()
-  io.write('\ntest_skip_past_tab_to_previous_word')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc def\tghi'}
@@ -150,11 +138,10 @@ function test_skip_past_tab_to_previous_word()
   Editor_state.cursor1 = {line=1, pos=10}  -- within third word
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-left')
-  check_eq(Editor_state.cursor1.pos, 9, 'F - test_skip_past_tab_to_previous_word')
+  check_eq(Editor_state.cursor1.pos, 9, 'check')
 end
 
 function test_skip_multiple_spaces_to_previous_word()
-  io.write('\ntest_skip_multiple_spaces_to_previous_word')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc  def'}
@@ -162,11 +149,10 @@ function test_skip_multiple_spaces_to_previous_word()
   Editor_state.cursor1 = {line=1, pos=6}  -- at the start of second word
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-left')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_skip_multiple_spaces_to_previous_word')
+  check_eq(Editor_state.cursor1.pos, 1, 'check')
 end
 
 function test_move_to_start_of_word_on_previous_line()
-  io.write('\ntest_move_to_start_of_word_on_previous_line')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc def', 'ghi'}
@@ -174,12 +160,11 @@ function test_move_to_start_of_word_on_previous_line()
   Editor_state.cursor1 = {line=2, pos=1}
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-left')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_move_to_start_of_word_on_previous_line/line')
-  check_eq(Editor_state.cursor1.pos, 5, 'F - test_move_to_start_of_word_on_previous_line/pos')
+  check_eq(Editor_state.cursor1.line, 1, 'line')
+  check_eq(Editor_state.cursor1.pos, 5, 'pos')
 end
 
 function test_move_past_end_of_word()
-  io.write('\ntest_move_past_end_of_word')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc def'}
@@ -187,11 +172,10 @@ function test_move_past_end_of_word()
   Editor_state.cursor1 = {line=1, pos=1}
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-right')
-  check_eq(Editor_state.cursor1.pos, 4, 'F - test_move_past_end_of_word')
+  check_eq(Editor_state.cursor1.pos, 4, 'check')
 end
 
 function test_skip_to_next_word()
-  io.write('\ntest_skip_to_next_word')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc def'}
@@ -199,11 +183,10 @@ function test_skip_to_next_word()
   Editor_state.cursor1 = {line=1, pos=4}  -- at the space between words
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-right')
-  check_eq(Editor_state.cursor1.pos, 8, 'F - test_skip_to_next_word')
+  check_eq(Editor_state.cursor1.pos, 8, 'check')
 end
 
 function test_skip_past_tab_to_next_word()
-  io.write('\ntest_skip_past_tab_to_next_word')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc\tdef'}
@@ -211,11 +194,10 @@ function test_skip_past_tab_to_next_word()
   Editor_state.cursor1 = {line=1, pos=1}  -- at the space between words
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-right')
-  check_eq(Editor_state.cursor1.pos, 4, 'F - test_skip_past_tab_to_next_word')
+  check_eq(Editor_state.cursor1.pos, 4, 'check')
 end
 
 function test_skip_multiple_spaces_to_next_word()
-  io.write('\ntest_skip_multiple_spaces_to_next_word')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc  def'}
@@ -223,11 +205,10 @@ function test_skip_multiple_spaces_to_next_word()
   Editor_state.cursor1 = {line=1, pos=4}  -- at the start of second word
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-right')
-  check_eq(Editor_state.cursor1.pos, 9, 'F - test_skip_multiple_spaces_to_next_word')
+  check_eq(Editor_state.cursor1.pos, 9, 'check')
 end
 
 function test_move_past_end_of_word_on_next_line()
-  io.write('\ntest_move_past_end_of_word_on_next_line')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc def', 'ghi'}
@@ -235,12 +216,11 @@ function test_move_past_end_of_word_on_next_line()
   Editor_state.cursor1 = {line=1, pos=8}
   edit.draw(Editor_state)
   edit.run_after_keychord(Editor_state, 'M-right')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_move_past_end_of_word_on_next_line/line')
-  check_eq(Editor_state.cursor1.pos, 4, 'F - test_move_past_end_of_word_on_next_line/pos')
+  check_eq(Editor_state.cursor1.line, 2, 'line')
+  check_eq(Editor_state.cursor1.pos, 4, 'pos')
 end
 
 function test_click_moves_cursor()
-  io.write('\ntest_click_moves_cursor')
   App.screen.init{width=50, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'xyz'}
@@ -251,15 +231,14 @@ function test_click_moves_cursor()
   Editor_state.selection1 = {}
   edit.draw(Editor_state)  -- populate line_cache.starty for each line Editor_state.line_cache
   edit.run_after_mouse_release(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_click_moves_cursor/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 2, 'F - test_click_moves_cursor/cursor:pos')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
   -- selection is empty to avoid perturbing future edits
-  check_nil(Editor_state.selection1.line, 'F - test_click_moves_cursor/selection:line')
-  check_nil(Editor_state.selection1.pos, 'F - test_click_moves_cursor/selection:pos')
+  check_nil(Editor_state.selection1.line, 'selection:line')
+  check_nil(Editor_state.selection1.pos, 'selection:pos')
 end
 
 function test_click_to_left_of_line()
-  io.write('\ntest_click_to_left_of_line')
   -- display a line with the cursor in the middle
   App.screen.init{width=50, height=80}
   Editor_state = edit.initialize_test_state()
@@ -272,13 +251,12 @@ function test_click_to_left_of_line()
   edit.draw(Editor_state)
   edit.run_after_mouse_click(Editor_state, Editor_state.left-4,Editor_state.top+5, 1)
   -- cursor moves to start of line
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_click_to_left_of_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_click_to_left_of_line/cursor:pos')
-  check_nil(Editor_state.selection1.line, 'F - test_click_to_left_of_line/selection is empty to avoid perturbing future edits')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
+  check_nil(Editor_state.selection1.line, 'selection is empty to avoid perturbing future edits')
 end
 
 function test_click_takes_margins_into_account()
-  io.write('\ntest_click_takes_margins_into_account')
   -- display two lines with cursor on one of them
   App.screen.init{width=100, height=80}
   Editor_state = edit.initialize_test_state()
@@ -292,13 +270,12 @@ function test_click_takes_margins_into_account()
   edit.draw(Editor_state)
   edit.run_after_mouse_click(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
   -- cursor moves
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_click_takes_margins_into_account/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 2, 'F - test_click_takes_margins_into_account/cursor:pos')
-  check_nil(Editor_state.selection1.line, 'F - test_click_takes_margins_into_account/selection is empty to avoid perturbing future edits')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
+  check_nil(Editor_state.selection1.line, 'selection is empty to avoid perturbing future edits')
 end
 
 function test_click_on_empty_line()
-  io.write('\ntest_click_on_empty_line')
   -- display two lines with the first one empty
   App.screen.init{width=50, height=80}
   Editor_state = edit.initialize_test_state()
@@ -311,11 +288,10 @@ function test_click_on_empty_line()
   edit.draw(Editor_state)
   edit.run_after_mouse_click(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
   -- cursor moves
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_click_on_empty_line/cursor')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor')
 end
 
 function test_draw_text()
-  io.write('\ntest_draw_text')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'ghi'}
@@ -325,15 +301,14 @@ function test_draw_text()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_draw_text/screen:1')
+  App.screen.check(y, 'abc', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_draw_text/screen:2')
+  App.screen.check(y, 'def', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_draw_text/screen:3')
+  App.screen.check(y, 'ghi', 'screen:3')
 end
 
 function test_draw_wrapping_text()
-  io.write('\ntest_draw_wrapping_text')
   App.screen.init{width=50, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'defgh', 'xyz'}
@@ -343,15 +318,14 @@ function test_draw_wrapping_text()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_draw_wrapping_text/screen:1')
+  App.screen.check(y, 'abc', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'de', 'F - test_draw_wrapping_text/screen:2')
+  App.screen.check(y, 'de', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'fgh', 'F - test_draw_wrapping_text/screen:3')
+  App.screen.check(y, 'fgh', 'screen:3')
 end
 
 function test_draw_word_wrapping_text()
-  io.write('\ntest_draw_word_wrapping_text')
   App.screen.init{width=60, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc def ghi', 'jkl'}
@@ -361,15 +335,14 @@ function test_draw_word_wrapping_text()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc ', 'F - test_draw_word_wrapping_text/screen:1')
+  App.screen.check(y, 'abc ', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def ', 'F - test_draw_word_wrapping_text/screen:2')
+  App.screen.check(y, 'def ', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_draw_word_wrapping_text/screen:3')
+  App.screen.check(y, 'ghi', 'screen:3')
 end
 
 function test_click_on_wrapping_line()
-  io.write('\ntest_click_on_wrapping_line')
   -- display two lines with cursor on one of them
   App.screen.init{width=50, height=80}
   Editor_state = edit.initialize_test_state()
@@ -382,13 +355,12 @@ function test_click_on_wrapping_line()
   edit.draw(Editor_state)
   edit.run_after_mouse_click(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
   -- cursor moves
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_click_on_wrapping_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 2, 'F - test_click_on_wrapping_line/cursor:pos')
-  check_nil(Editor_state.selection1.line, 'F - test_click_on_wrapping_line/selection is empty to avoid perturbing future edits')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
+  check_nil(Editor_state.selection1.line, 'selection is empty to avoid perturbing future edits')
 end
 
 function test_click_on_wrapping_line_takes_margins_into_account()
-  io.write('\ntest_click_on_wrapping_line_takes_margins_into_account')
   -- display two lines with cursor on one of them
   App.screen.init{width=100, height=80}
   Editor_state = edit.initialize_test_state()
@@ -402,14 +374,13 @@ function test_click_on_wrapping_line_takes_margins_into_account()
   edit.draw(Editor_state)
   edit.run_after_mouse_click(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
   -- cursor moves
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_click_on_wrapping_line_takes_margins_into_account/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 2, 'F - test_click_on_wrapping_line_takes_margins_into_account/cursor:pos')
-  check_nil(Editor_state.selection1.line, 'F - test_click_on_wrapping_line_takes_margins_into_account/selection is empty to avoid perturbing future edits')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
+  check_nil(Editor_state.selection1.line, 'selection is empty to avoid perturbing future edits')
 end
 
 function test_draw_text_wrapping_within_word()
   -- arrange a screen line that needs to be split within a word
-  io.write('\ntest_draw_text_wrapping_within_word')
   App.screen.init{width=60, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abcd e fghijk', 'xyz'}
@@ -419,16 +390,15 @@ function test_draw_text_wrapping_within_word()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abcd ', 'F - test_draw_text_wrapping_within_word/screen:1')
+  App.screen.check(y, 'abcd ', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'e fgh', 'F - test_draw_text_wrapping_within_word/screen:2')
+  App.screen.check(y, 'e fgh', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ijk', 'F - test_draw_text_wrapping_within_word/screen:3')
+  App.screen.check(y, 'ijk', 'screen:3')
 end
 
 function test_draw_wrapping_text_containing_non_ascii()
   -- draw a long line containing non-ASCII
-  io.write('\ntest_draw_wrapping_text_containing_non_ascii')
   App.screen.init{width=60, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'madam I’m adam', 'xyz'}  -- notice the non-ASCII apostrophe
@@ -438,15 +408,14 @@ function test_draw_wrapping_text_containing_non_ascii()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'mad', 'F - test_draw_wrapping_text_containing_non_ascii/screen:1')
+  App.screen.check(y, 'mad', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'am I', 'F - test_draw_wrapping_text_containing_non_ascii/screen:2')
+  App.screen.check(y, 'am I', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, '’m a', 'F - test_draw_wrapping_text_containing_non_ascii/screen:3')
+  App.screen.check(y, '’m a', 'screen:3')
 end
 
 function test_click_on_wrapping_line()
-  io.write('\ntest_click_on_wrapping_line')
   -- display a wrapping line
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -458,19 +427,18 @@ function test_click_on_wrapping_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'madam ', 'F - test_click_on_wrapping_line/baseline/screen:1')
+  App.screen.check(y, 'madam ', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, "I'm ad", 'F - test_click_on_wrapping_line/baseline/screen:2')
+  App.screen.check(y, "I'm ad", 'baseline/screen:2')
   y = y + Editor_state.line_height
   -- click past end of second screen line
   edit.run_after_mouse_click(Editor_state, App.screen.width-2,y-2, 1)
   -- cursor moves to end of screen line
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_click_on_wrapping_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 12, 'F - test_click_on_wrapping_line/cursor:pos')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 12, 'cursor:pos')
 end
 
 function test_click_on_wrapping_line_rendered_from_partway_at_top_of_screen()
-  io.write('\ntest_click_on_wrapping_line_rendered_from_partway_at_top_of_screen')
   -- display a wrapping line from its second screen line
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -482,17 +450,16 @@ function test_click_on_wrapping_line_rendered_from_partway_at_top_of_screen()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, "I'm ad", 'F - test_click_on_wrapping_line_rendered_from_partway_at_top_of_screen/baseline/screen:2')
+  App.screen.check(y, "I'm ad", 'baseline/screen:2')
   y = y + Editor_state.line_height
   -- click past end of second screen line
   edit.run_after_mouse_click(Editor_state, App.screen.width-2,y-2, 1)
   -- cursor moves to end of screen line
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_click_on_wrapping_line_rendered_from_partway_at_top_of_screen/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 12, 'F - test_click_on_wrapping_line_rendered_from_partway_at_top_of_screen/cursor:pos')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 12, 'cursor:pos')
 end
 
 function test_click_past_end_of_wrapping_line()
-  io.write('\ntest_click_past_end_of_wrapping_line')
   -- display a wrapping line
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -504,20 +471,19 @@ function test_click_past_end_of_wrapping_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'madam ', 'F - test_click_past_end_of_wrapping_line/baseline/screen:1')
+  App.screen.check(y, 'madam ', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, "I'm ad", 'F - test_click_past_end_of_wrapping_line/baseline/screen:2')
+  App.screen.check(y, "I'm ad", 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'am', 'F - test_click_past_end_of_wrapping_line/baseline/screen:3')
+  App.screen.check(y, 'am', 'baseline/screen:3')
   y = y + Editor_state.line_height
   -- click past the end of it
   edit.run_after_mouse_click(Editor_state, App.screen.width-2,y-2, 1)
   -- cursor moves to end of line
-  check_eq(Editor_state.cursor1.pos, 15, 'F - test_click_past_end_of_wrapping_line/cursor')  -- one more than the number of UTF-8 code-points
+  check_eq(Editor_state.cursor1.pos, 15, 'cursor')  -- one more than the number of UTF-8 code-points
 end
 
 function test_click_past_end_of_wrapping_line_containing_non_ascii()
-  io.write('\ntest_click_past_end_of_wrapping_line_containing_non_ascii')
   -- display a wrapping line containing non-ASCII
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -529,20 +495,19 @@ function test_click_past_end_of_wrapping_line_containing_non_ascii()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'madam ', 'F - test_click_past_end_of_wrapping_line_containing_non_ascii/baseline/screen:1')
+  App.screen.check(y, 'madam ', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'I’m ad', 'F - test_click_past_end_of_wrapping_line_containing_non_ascii/baseline/screen:2')
+  App.screen.check(y, 'I’m ad', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'am', 'F - test_click_past_end_of_wrapping_line_containing_non_ascii/baseline/screen:3')
+  App.screen.check(y, 'am', 'baseline/screen:3')
   y = y + Editor_state.line_height
   -- click past the end of it
   edit.run_after_mouse_click(Editor_state, App.screen.width-2,y-2, 1)
   -- cursor moves to end of line
-  check_eq(Editor_state.cursor1.pos, 15, 'F - test_click_past_end_of_wrapping_line_containing_non_ascii/cursor')  -- one more than the number of UTF-8 code-points
+  check_eq(Editor_state.cursor1.pos, 15, 'cursor')  -- one more than the number of UTF-8 code-points
 end
 
 function test_click_past_end_of_word_wrapping_line()
-  io.write('\ntest_click_past_end_of_word_wrapping_line')
   -- display a long line wrapping at a word boundary on a screen of more realistic length
   App.screen.init{width=160, height=80}
   Editor_state = edit.initialize_test_state()
@@ -555,16 +520,15 @@ function test_click_past_end_of_word_wrapping_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'the quick brown fox ', 'F - test_click_past_end_of_word_wrapping_line/baseline/screen:1')
+  App.screen.check(y, 'the quick brown fox ', 'baseline/screen:1')
   y = y + Editor_state.line_height
   -- click past the end of the screen line
   edit.run_after_mouse_click(Editor_state, App.screen.width-2,y-2, 1)
   -- cursor moves to end of screen line
-  check_eq(Editor_state.cursor1.pos, 20, 'F - test_click_past_end_of_word_wrapping_line/cursor')
+  check_eq(Editor_state.cursor1.pos, 20, 'cursor')
 end
 
 function test_select_text()
-  io.write('\ntest_select_text')
   -- display a line of text
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -580,14 +544,13 @@ function test_select_text()
   App.fake_key_release('lshift')
   edit.key_release(Editor_state, 'lshift')
   -- selection persists even after shift is released
-  check_eq(Editor_state.selection1.line, 1, 'F - test_select_text/selection:line')
-  check_eq(Editor_state.selection1.pos, 1, 'F - test_select_text/selection:pos')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_select_text/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 2, 'F - test_select_text/cursor:pos')
+  check_eq(Editor_state.selection1.line, 1, 'selection:line')
+  check_eq(Editor_state.selection1.pos, 1, 'selection:pos')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
 end
 
 function test_cursor_movement_without_shift_resets_selection()
-  io.write('\ntest_cursor_movement_without_shift_resets_selection')
   -- display a line of text with some part selected
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -601,12 +564,11 @@ function test_cursor_movement_without_shift_resets_selection()
   -- press an arrow key without shift
   edit.run_after_keychord(Editor_state, 'right')
   -- no change to data, selection is reset
-  check_nil(Editor_state.selection1.line, 'F - test_cursor_movement_without_shift_resets_selection')
-  check_eq(Editor_state.lines[1].data, 'abc', 'F - test_cursor_movement_without_shift_resets_selection/data')
+  check_nil(Editor_state.selection1.line, 'check')
+  check_eq(Editor_state.lines[1].data, 'abc', 'data')
 end
 
 function test_edit_deletes_selection()
-  io.write('\ntest_edit_deletes_selection')
   -- display a line of text with some part selected
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -620,11 +582,10 @@ function test_edit_deletes_selection()
   -- press a key
   edit.run_after_text_input(Editor_state, 'x')
   -- selected text is deleted and replaced with the key
-  check_eq(Editor_state.lines[1].data, 'xbc', 'F - test_edit_deletes_selection')
+  check_eq(Editor_state.lines[1].data, 'xbc', 'check')
 end
 
 function test_edit_with_shift_key_deletes_selection()
-  io.write('\ntest_edit_with_shift_key_deletes_selection')
   -- display a line of text with some part selected
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -642,12 +603,11 @@ function test_edit_with_shift_key_deletes_selection()
   edit.key_release(Editor_state, 'd')
   App.fake_key_release('lshift')
   -- selected text is deleted and replaced with the key
-  check_nil(Editor_state.selection1.line, 'F - test_edit_with_shift_key_deletes_selection')
-  check_eq(Editor_state.lines[1].data, 'Dbc', 'F - test_edit_with_shift_key_deletes_selection/data')
+  check_nil(Editor_state.selection1.line, 'check')
+  check_eq(Editor_state.lines[1].data, 'Dbc', 'data')
 end
 
 function test_copy_does_not_reset_selection()
-  io.write('\ntest_copy_does_not_reset_selection')
   -- display a line of text with a selection
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -660,13 +620,12 @@ function test_copy_does_not_reset_selection()
   edit.draw(Editor_state)
   -- copy selection
   edit.run_after_keychord(Editor_state, 'C-c')
-  check_eq(App.clipboard, 'a', 'F - test_copy_does_not_reset_selection/clipboard')
+  check_eq(App.clipboard, 'a', 'clipboard')
   -- selection is reset since shift key is not pressed
-  check(Editor_state.selection1.line, 'F - test_copy_does_not_reset_selection')
+  check(Editor_state.selection1.line, 'check')
 end
 
 function test_cut()
-  io.write('\ntest_cut')
   -- display a line of text with some part selected
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -679,13 +638,12 @@ function test_cut()
   edit.draw(Editor_state)
   -- press a key
   edit.run_after_keychord(Editor_state, 'C-x')
-  check_eq(App.clipboard, 'a', 'F - test_cut/clipboard')
+  check_eq(App.clipboard, 'a', 'clipboard')
   -- selected text is deleted
-  check_eq(Editor_state.lines[1].data, 'bc', 'F - test_cut/data')
+  check_eq(Editor_state.lines[1].data, 'bc', 'data')
 end
 
 function test_paste_replaces_selection()
-  io.write('\ntest_paste_replaces_selection')
   -- display a line of text with a selection
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -702,11 +660,10 @@ function test_paste_replaces_selection()
   edit.run_after_keychord(Editor_state, 'C-v')
   -- selection is reset since shift key is not pressed
   -- selection includes the newline, so it's also deleted
-  check_eq(Editor_state.lines[1].data, 'xyzdef', 'F - test_paste_replaces_selection')
+  check_eq(Editor_state.lines[1].data, 'xyzdef', 'check')
 end
 
 function test_deleting_selection_may_scroll()
-  io.write('\ntest_deleting_selection_may_scroll')
   -- display lines 2/3/4
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
@@ -717,22 +674,21 @@ function test_deleting_selection_may_scroll()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_deleting_selection_may_scroll/baseline/screen:1')
+  App.screen.check(y, 'def', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_deleting_selection_may_scroll/baseline/screen:2')
+  App.screen.check(y, 'ghi', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_deleting_selection_may_scroll/baseline/screen:3')
+  App.screen.check(y, 'jkl', 'baseline/screen:3')
   -- set up a selection starting above the currently displayed page
   Editor_state.selection1 = {line=1, pos=2}
   -- delete selection
   edit.run_after_keychord(Editor_state, 'backspace')
   -- page scrolls up
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_deleting_selection_may_scroll')
-  check_eq(Editor_state.lines[1].data, 'ahi', 'F - test_deleting_selection_may_scroll/data')
+  check_eq(Editor_state.screen_top1.line, 1, 'check')
+  check_eq(Editor_state.lines[1].data, 'ahi', 'data')
 end
 
 function test_edit_wrapping_text()
-  io.write('\ntest_edit_wrapping_text')
   App.screen.init{width=50, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'xyz'}
@@ -743,15 +699,14 @@ function test_edit_wrapping_text()
   edit.draw(Editor_state)
   edit.run_after_text_input(Editor_state, 'g')
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_edit_wrapping_text/screen:1')
+  App.screen.check(y, 'abc', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'de', 'F - test_edit_wrapping_text/screen:2')
+  App.screen.check(y, 'de', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'fg', 'F - test_edit_wrapping_text/screen:3')
+  App.screen.check(y, 'fg', 'screen:3')
 end
 
 function test_insert_newline()
-  io.write('\ntest_insert_newline')
   -- display a few lines
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -762,26 +717,25 @@ function test_insert_newline()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_insert_newline/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_insert_newline/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_insert_newline/baseline/screen:3')
+  App.screen.check(y, 'ghi', 'baseline/screen:3')
   -- hitting the enter key splits the line
   edit.run_after_keychord(Editor_state, 'return')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_insert_newline/screen_top')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_insert_newline/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_insert_newline/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'a', 'F - test_insert_newline/screen:1')
+  App.screen.check(y, 'a', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'bc', 'F - test_insert_newline/screen:2')
+  App.screen.check(y, 'bc', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_insert_newline/screen:3')
+  App.screen.check(y, 'def', 'screen:3')
 end
 
 function test_insert_newline_at_start_of_line()
-  io.write('\ntest_insert_newline_at_start_of_line')
   -- display a line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -792,14 +746,13 @@ function test_insert_newline_at_start_of_line()
   Editor_state.screen_bottom1 = {}
   -- hitting the enter key splits the line
   edit.run_after_keychord(Editor_state, 'return')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_insert_newline_at_start_of_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_insert_newline_at_start_of_line/cursor:pos')
-  check_eq(Editor_state.lines[1].data, '', 'F - test_insert_newline_at_start_of_line/data:1')
-  check_eq(Editor_state.lines[2].data, 'abc', 'F - test_insert_newline_at_start_of_line/data:2')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
+  check_eq(Editor_state.lines[1].data, '', 'data:1')
+  check_eq(Editor_state.lines[2].data, 'abc', 'data:2')
 end
 
 function test_insert_from_clipboard()
-  io.write('\ntest_insert_from_clipboard')
   -- display a few lines
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -810,27 +763,26 @@ function test_insert_from_clipboard()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_insert_from_clipboard/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_insert_from_clipboard/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_insert_from_clipboard/baseline/screen:3')
+  App.screen.check(y, 'ghi', 'baseline/screen:3')
   -- paste some text including a newline, check that new line is created
   App.clipboard = 'xy\nz'
   edit.run_after_keychord(Editor_state, 'C-v')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_insert_from_clipboard/screen_top')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_insert_from_clipboard/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 2, 'F - test_insert_from_clipboard/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'axy', 'F - test_insert_from_clipboard/screen:1')
+  App.screen.check(y, 'axy', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'zbc', 'F - test_insert_from_clipboard/screen:2')
+  App.screen.check(y, 'zbc', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_insert_from_clipboard/screen:3')
+  App.screen.check(y, 'def', 'screen:3')
 end
 
 function test_select_text_using_mouse()
-  io.write('\ntest_select_text_using_mouse')
   App.screen.init{width=50, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'xyz'}
@@ -844,14 +796,13 @@ function test_select_text_using_mouse()
   edit.run_after_mouse_press(Editor_state, Editor_state.left+8,Editor_state.top+5, 1)
   -- drag and release somewhere else
   edit.run_after_mouse_release(Editor_state, Editor_state.left+20,Editor_state.top+Editor_state.line_height+5, 1)
-  check_eq(Editor_state.selection1.line, 1, 'F - test_select_text_using_mouse/selection:line')
-  check_eq(Editor_state.selection1.pos, 2, 'F - test_select_text_using_mouse/selection:pos')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_select_text_using_mouse/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 4, 'F - test_select_text_using_mouse/cursor:pos')
+  check_eq(Editor_state.selection1.line, 1, 'selection:line')
+  check_eq(Editor_state.selection1.pos, 2, 'selection:pos')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 4, 'cursor:pos')
 end
 
 function test_select_text_using_mouse_and_shift()
-  io.write('\ntest_select_text_using_mouse_and_shift')
   App.screen.init{width=50, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'xyz'}
@@ -869,14 +820,13 @@ function test_select_text_using_mouse_and_shift()
   edit.run_after_mouse_press(Editor_state, Editor_state.left+20,Editor_state.top+5, 1)
   edit.run_after_mouse_release(Editor_state, Editor_state.left+20,Editor_state.top+Editor_state.line_height+5, 1)
   App.fake_key_release('lshift')
-  check_eq(Editor_state.selection1.line, 1, 'F - test_select_text_using_mouse_and_shift/selection:line')
-  check_eq(Editor_state.selection1.pos, 2, 'F - test_select_text_using_mouse_and_shift/selection:pos')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_select_text_using_mouse_and_shift/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 4, 'F - test_select_text_using_mouse_and_shift/cursor:pos')
+  check_eq(Editor_state.selection1.line, 1, 'selection:line')
+  check_eq(Editor_state.selection1.pos, 2, 'selection:pos')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 4, 'cursor:pos')
 end
 
 function test_select_text_repeatedly_using_mouse_and_shift()
-  io.write('\ntest_select_text_repeatedly_using_mouse_and_shift')
   App.screen.init{width=50, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'xyz'}
@@ -900,14 +850,13 @@ function test_select_text_repeatedly_using_mouse_and_shift()
   edit.run_after_mouse_release(Editor_state, Editor_state.left+8,Editor_state.top+Editor_state.line_height+5, 1)
   App.fake_key_release('lshift')
   -- selection is between first and third location. forget the second location, not the first.
-  check_eq(Editor_state.selection1.line, 1, 'F - test_select_text_repeatedly_using_mouse_and_shift/selection:line')
-  check_eq(Editor_state.selection1.pos, 2, 'F - test_select_text_repeatedly_using_mouse_and_shift/selection:pos')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_select_text_repeatedly_using_mouse_and_shift/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 2, 'F - test_select_text_repeatedly_using_mouse_and_shift/cursor:pos')
+  check_eq(Editor_state.selection1.line, 1, 'selection:line')
+  check_eq(Editor_state.selection1.pos, 2, 'selection:pos')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
 end
 
 function test_cut_without_selection()
-  io.write('\ntest_cut_without_selection')
   -- display a few lines
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -921,11 +870,10 @@ function test_cut_without_selection()
   -- try to cut without selecting text
   edit.run_after_keychord(Editor_state, 'C-x')
   -- no crash
-  check_nil(Editor_state.selection1.line, 'F - test_cut_without_selection')
+  check_nil(Editor_state.selection1.line, 'check')
 end
 
 function test_pagedown()
-  io.write('\ntest_pagedown')
   App.screen.init{width=120, height=45}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'ghi'}
@@ -936,21 +884,20 @@ function test_pagedown()
   -- initially the first two lines are displayed
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_pagedown/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_pagedown/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   -- after pagedown the bottom line becomes the top
   edit.run_after_keychord(Editor_state, 'pagedown')
-  check_eq(Editor_state.screen_top1.line, 2, 'F - test_pagedown/screen_top')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_pagedown/cursor')
+  check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor')
   y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_pagedown/screen:1')
+  App.screen.check(y, 'def', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_pagedown/screen:2')
+  App.screen.check(y, 'ghi', 'screen:2')
 end
 
 function test_pagedown_often_shows_start_of_wrapping_line()
-  io.write('\ntest_pagedown_often_shows_start_of_wrapping_line')
   -- draw a few lines ending in part of a wrapping line
   App.screen.init{width=50, height=60}
   Editor_state = edit.initialize_test_state()
@@ -961,27 +908,26 @@ function test_pagedown_often_shows_start_of_wrapping_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_pagedown_often_shows_start_of_wrapping_line/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def ', 'F - test_pagedown_often_shows_start_of_wrapping_line/baseline/screen:2')
+  App.screen.check(y, 'def ', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi ', 'F - test_pagedown_often_shows_start_of_wrapping_line/baseline/screen:3')
+  App.screen.check(y, 'ghi ', 'baseline/screen:3')
   -- after pagedown we start drawing from the bottom _line_ (multiple screen lines)
   edit.run_after_keychord(Editor_state, 'pagedown')
-  check_eq(Editor_state.screen_top1.line, 2, 'F - test_pagedown_often_shows_start_of_wrapping_line/screen_top:line')
-  check_eq(Editor_state.screen_top1.pos, 1, 'F - test_pagedown_often_shows_start_of_wrapping_line/screen_top:pos')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_pagedown_often_shows_start_of_wrapping_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_pagedown_often_shows_start_of_wrapping_line/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 2, 'screen_top:line')
+  check_eq(Editor_state.screen_top1.pos, 1, 'screen_top:pos')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'def ', 'F - test_pagedown_often_shows_start_of_wrapping_line/screen:1')
+  App.screen.check(y, 'def ', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi ', 'F - test_pagedown_often_shows_start_of_wrapping_line/screen:2')
+  App.screen.check(y, 'ghi ', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_pagedown_often_shows_start_of_wrapping_line/screen:3')
+  App.screen.check(y, 'jkl', 'screen:3')
 end
 
 function test_pagedown_can_start_from_middle_of_long_wrapping_line()
-  io.write('\ntest_pagedown_can_start_from_middle_of_long_wrapping_line')
   -- draw a few lines starting from a very long wrapping line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -992,25 +938,24 @@ function test_pagedown_can_start_from_middle_of_long_wrapping_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc ', 'F - test_pagedown_can_start_from_middle_of_long_wrapping_line/baseline/screen:1')
+  App.screen.check(y, 'abc ', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def ', 'F - test_pagedown_can_start_from_middle_of_long_wrapping_line/baseline/screen:2')
+  App.screen.check(y, 'def ', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi ', 'F - test_pagedown_can_start_from_middle_of_long_wrapping_line/baseline/screen:3')
+  App.screen.check(y, 'ghi ', 'baseline/screen:3')
   -- after pagedown we scroll down the very long wrapping line
   edit.run_after_keychord(Editor_state, 'pagedown')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_pagedown_can_start_from_middle_of_long_wrapping_line/screen_top:line')
-  check_eq(Editor_state.screen_top1.pos, 9, 'F - test_pagedown_can_start_from_middle_of_long_wrapping_line/screen_top:pos')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top:line')
+  check_eq(Editor_state.screen_top1.pos, 9, 'screen_top:pos')
   y = Editor_state.top
-  App.screen.check(y, 'ghi ', 'F - test_pagedown_can_start_from_middle_of_long_wrapping_line/screen:1')
+  App.screen.check(y, 'ghi ', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl ', 'F - test_pagedown_can_start_from_middle_of_long_wrapping_line/screen:2')
+  App.screen.check(y, 'jkl ', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno ', 'F - test_pagedown_can_start_from_middle_of_long_wrapping_line/screen:3')
+  App.screen.check(y, 'mno ', 'screen:3')
 end
 
 function test_pagedown_never_moves_up()
-  io.write('\ntest_pagedown_never_moves_up')
   -- draw the final screen line of a wrapping line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1022,12 +967,11 @@ function test_pagedown_never_moves_up()
   edit.draw(Editor_state)
   -- pagedown makes no change
   edit.run_after_keychord(Editor_state, 'pagedown')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_pagedown_never_moves_up/screen_top:line')
-  check_eq(Editor_state.screen_top1.pos, 9, 'F - test_pagedown_never_moves_up/screen_top:pos')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top:line')
+  check_eq(Editor_state.screen_top1.pos, 9, 'screen_top:pos')
 end
 
 function test_down_arrow_moves_cursor()
-  io.write('\ntest_down_arrow_moves_cursor')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'ghi', 'jkl'}
@@ -1038,26 +982,25 @@ function test_down_arrow_moves_cursor()
   -- initially the first three lines are displayed
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_down_arrow_moves_cursor/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_down_arrow_moves_cursor/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_down_arrow_moves_cursor/baseline/screen:3')
+  App.screen.check(y, 'ghi', 'baseline/screen:3')
   -- after hitting the down arrow, the cursor moves down by 1 line
   edit.run_after_keychord(Editor_state, 'down')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_down_arrow_moves_cursor/screen_top')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_down_arrow_moves_cursor/cursor')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor')
   -- the screen is unchanged
   y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_down_arrow_moves_cursor/screen:1')
+  App.screen.check(y, 'abc', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_down_arrow_moves_cursor/screen:2')
+  App.screen.check(y, 'def', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_down_arrow_moves_cursor/screen:3')
+  App.screen.check(y, 'ghi', 'screen:3')
 end
 
 function test_down_arrow_scrolls_down_by_one_line()
-  io.write('\ntest_down_arrow_scrolls_down_by_one_line')
   -- display the first three lines with the cursor on the bottom line
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1068,25 +1011,24 @@ function test_down_arrow_scrolls_down_by_one_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_down_arrow_scrolls_down_by_one_line/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_down_arrow_scrolls_down_by_one_line/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_down_arrow_scrolls_down_by_one_line/baseline/screen:3')
+  App.screen.check(y, 'ghi', 'baseline/screen:3')
   -- after hitting the down arrow the screen scrolls down by one line
   edit.run_after_keychord(Editor_state, 'down')
-  check_eq(Editor_state.screen_top1.line, 2, 'F - test_down_arrow_scrolls_down_by_one_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 4, 'F - test_down_arrow_scrolls_down_by_one_line/cursor')
+  check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 4, 'cursor')
   y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_down_arrow_scrolls_down_by_one_line/screen:1')
+  App.screen.check(y, 'def', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_down_arrow_scrolls_down_by_one_line/screen:2')
+  App.screen.check(y, 'ghi', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_down_arrow_scrolls_down_by_one_line/screen:3')
+  App.screen.check(y, 'jkl', 'screen:3')
 end
 
 function test_down_arrow_scrolls_down_by_one_screen_line()
-  io.write('\ntest_down_arrow_scrolls_down_by_one_screen_line')
   -- display the first three lines with the cursor on the bottom line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1097,26 +1039,25 @@ function test_down_arrow_scrolls_down_by_one_screen_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_down_arrow_scrolls_down_by_one_screen_line/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_down_arrow_scrolls_down_by_one_screen_line/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi ', 'F - test_down_arrow_scrolls_down_by_one_screen_line/baseline/screen:3')  -- line wrapping includes trailing whitespace
+  App.screen.check(y, 'ghi ', 'baseline/screen:3')  -- line wrapping includes trailing whitespace
   -- after hitting the down arrow the screen scrolls down by one line
   edit.run_after_keychord(Editor_state, 'down')
-  check_eq(Editor_state.screen_top1.line, 2, 'F - test_down_arrow_scrolls_down_by_one_screen_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_down_arrow_scrolls_down_by_one_screen_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 5, 'F - test_down_arrow_scrolls_down_by_one_screen_line/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 5, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_down_arrow_scrolls_down_by_one_screen_line/screen:1')
+  App.screen.check(y, 'def', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi ', 'F - test_down_arrow_scrolls_down_by_one_screen_line/screen:2')
+  App.screen.check(y, 'ghi ', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_down_arrow_scrolls_down_by_one_screen_line/screen:3')
+  App.screen.check(y, 'jkl', 'screen:3')
 end
 
 function test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word()
-  io.write('\ntest_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word')
   -- display the first three lines with the cursor on the bottom line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1127,26 +1068,25 @@ function test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghij', 'F - test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word/baseline/screen:3')
+  App.screen.check(y, 'ghij', 'baseline/screen:3')
   -- after hitting the down arrow the screen scrolls down by one line
   edit.run_after_keychord(Editor_state, 'down')
-  check_eq(Editor_state.screen_top1.line, 2, 'F - test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 5, 'F - test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 5, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word/screen:1')
+  App.screen.check(y, 'def', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghij', 'F - test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word/screen:2')
+  App.screen.check(y, 'ghij', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'kl', 'F - test_down_arrow_scrolls_down_by_one_screen_line_after_splitting_within_word/screen:3')
+  App.screen.check(y, 'kl', 'screen:3')
 end
 
 function test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up()
-  io.write('\ntest_pagedown_followed_by_down_arrow_does_not_scroll_screen_up')
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'ghijkl', 'mno'}
@@ -1156,31 +1096,30 @@ function test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghij', 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/baseline/screen:3')
+  App.screen.check(y, 'ghij', 'baseline/screen:3')
   -- after hitting pagedown the screen scrolls down to start of a long line
   edit.run_after_keychord(Editor_state, 'pagedown')
-  check_eq(Editor_state.screen_top1.line, 3, 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/baseline2/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/baseline2/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/baseline2/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 3, 'baseline2/screen_top')
+  check_eq(Editor_state.cursor1.line, 3, 'baseline2/cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'baseline2/cursor:pos')
   -- after hitting down arrow the screen doesn't scroll down further, and certainly doesn't scroll up
   edit.run_after_keychord(Editor_state, 'down')
-  check_eq(Editor_state.screen_top1.line, 3, 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 5, 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 3, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 5, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'ghij', 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/screen:1')
+  App.screen.check(y, 'ghij', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'kl', 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/screen:2')
+  App.screen.check(y, 'kl', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_pagedown_followed_by_down_arrow_does_not_scroll_screen_up/screen:3')
+  App.screen.check(y, 'mno', 'screen:3')
 end
 
 function test_up_arrow_moves_cursor()
-  io.write('\ntest_up_arrow_moves_cursor')
   -- display the first 3 lines with the cursor on the bottom line
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1191,26 +1130,25 @@ function test_up_arrow_moves_cursor()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_up_arrow_moves_cursor/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_up_arrow_moves_cursor/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_up_arrow_moves_cursor/baseline/screen:3')
+  App.screen.check(y, 'ghi', 'baseline/screen:3')
   -- after hitting the up arrow the cursor moves up by 1 line
   edit.run_after_keychord(Editor_state, 'up')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_up_arrow_moves_cursor/screen_top')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_up_arrow_moves_cursor/cursor')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor')
   -- the screen is unchanged
   y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_up_arrow_moves_cursor/screen:1')
+  App.screen.check(y, 'abc', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_up_arrow_moves_cursor/screen:2')
+  App.screen.check(y, 'def', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_up_arrow_moves_cursor/screen:3')
+  App.screen.check(y, 'ghi', 'screen:3')
 end
 
 function test_up_arrow_scrolls_up_by_one_line()
-  io.write('\ntest_up_arrow_scrolls_up_by_one_line')
   -- display the lines 2/3/4 with the cursor on line 2
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1221,25 +1159,24 @@ function test_up_arrow_scrolls_up_by_one_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_up_arrow_scrolls_up_by_one_line/baseline/screen:1')
+  App.screen.check(y, 'def', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_up_arrow_scrolls_up_by_one_line/baseline/screen:2')
+  App.screen.check(y, 'ghi', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_up_arrow_scrolls_up_by_one_line/baseline/screen:3')
+  App.screen.check(y, 'jkl', 'baseline/screen:3')
   -- after hitting the up arrow the screen scrolls up by one line
   edit.run_after_keychord(Editor_state, 'up')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_up_arrow_scrolls_up_by_one_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_up_arrow_scrolls_up_by_one_line/cursor')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor')
   y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_up_arrow_scrolls_up_by_one_line/screen:1')
+  App.screen.check(y, 'abc', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_up_arrow_scrolls_up_by_one_line/screen:2')
+  App.screen.check(y, 'def', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_up_arrow_scrolls_up_by_one_line/screen:3')
+  App.screen.check(y, 'ghi', 'screen:3')
 end
 
 function test_up_arrow_scrolls_up_by_one_screen_line()
-  io.write('\ntest_up_arrow_scrolls_up_by_one_screen_line')
   -- display lines starting from second screen line of a line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1250,25 +1187,24 @@ function test_up_arrow_scrolls_up_by_one_screen_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'jkl', 'F - test_up_arrow_scrolls_up_by_one_screen_line/baseline/screen:1')
+  App.screen.check(y, 'jkl', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_up_arrow_scrolls_up_by_one_screen_line/baseline/screen:2')
+  App.screen.check(y, 'mno', 'baseline/screen:2')
   -- after hitting the up arrow the screen scrolls up to first screen line
   edit.run_after_keychord(Editor_state, 'up')
   y = Editor_state.top
-  App.screen.check(y, 'ghi ', 'F - test_up_arrow_scrolls_up_by_one_screen_line/screen:1')
+  App.screen.check(y, 'ghi ', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_up_arrow_scrolls_up_by_one_screen_line/screen:2')
+  App.screen.check(y, 'jkl', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_up_arrow_scrolls_up_by_one_screen_line/screen:3')
-  check_eq(Editor_state.screen_top1.line, 3, 'F - test_up_arrow_scrolls_up_by_one_screen_line/screen_top')
-  check_eq(Editor_state.screen_top1.pos, 1, 'F - test_up_arrow_scrolls_up_by_one_screen_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_up_arrow_scrolls_up_by_one_screen_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_up_arrow_scrolls_up_by_one_screen_line/cursor:pos')
+  App.screen.check(y, 'mno', 'screen:3')
+  check_eq(Editor_state.screen_top1.line, 3, 'screen_top:line')
+  check_eq(Editor_state.screen_top1.pos, 1, 'screen_top:pos')
+  check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
 end
 
 function test_up_arrow_scrolls_up_to_final_screen_line()
-  io.write('\ntest_up_arrow_scrolls_up_to_final_screen_line')
   -- display lines starting just after a long line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1279,27 +1215,26 @@ function test_up_arrow_scrolls_up_to_final_screen_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'ghi', 'F - test_up_arrow_scrolls_up_to_final_screen_line/baseline/screen:1')
+  App.screen.check(y, 'ghi', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_up_arrow_scrolls_up_to_final_screen_line/baseline/screen:2')
+  App.screen.check(y, 'jkl', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_up_arrow_scrolls_up_to_final_screen_line/baseline/screen:3')
+  App.screen.check(y, 'mno', 'baseline/screen:3')
   -- after hitting the up arrow the screen scrolls up to final screen line of previous line
   edit.run_after_keychord(Editor_state, 'up')
   y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_up_arrow_scrolls_up_to_final_screen_line/screen:1')
+  App.screen.check(y, 'def', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_up_arrow_scrolls_up_to_final_screen_line/screen:2')
+  App.screen.check(y, 'ghi', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_up_arrow_scrolls_up_to_final_screen_line/screen:3')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_up_arrow_scrolls_up_to_final_screen_line/screen_top')
-  check_eq(Editor_state.screen_top1.pos, 5, 'F - test_up_arrow_scrolls_up_to_final_screen_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_up_arrow_scrolls_up_to_final_screen_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 5, 'F - test_up_arrow_scrolls_up_to_final_screen_line/cursor:pos')
+  App.screen.check(y, 'jkl', 'screen:3')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top:line')
+  check_eq(Editor_state.screen_top1.pos, 5, 'screen_top:pos')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 5, 'cursor:pos')
 end
 
 function test_up_arrow_scrolls_up_to_empty_line()
-  io.write('\ntest_up_arrow_scrolls_up_to_empty_line')
   -- display a screenful of text with an empty line just above it outside the screen
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1310,25 +1245,24 @@ function test_up_arrow_scrolls_up_to_empty_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_up_arrow_scrolls_up_to_empty_line/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_up_arrow_scrolls_up_to_empty_line/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_up_arrow_scrolls_up_to_empty_line/baseline/screen:3')
+  App.screen.check(y, 'ghi', 'baseline/screen:3')
   -- after hitting the up arrow the screen scrolls up by one line
   edit.run_after_keychord(Editor_state, 'up')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_up_arrow_scrolls_up_to_empty_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_up_arrow_scrolls_up_to_empty_line/cursor')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor')
   y = Editor_state.top
   -- empty first line
   y = y + Editor_state.line_height
-  App.screen.check(y, 'abc', 'F - test_up_arrow_scrolls_up_to_empty_line/screen:2')
+  App.screen.check(y, 'abc', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_up_arrow_scrolls_up_to_empty_line/screen:3')
+  App.screen.check(y, 'def', 'screen:3')
 end
 
 function test_pageup()
-  io.write('\ntest_pageup')
   App.screen.init{width=120, height=45}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'ghi'}
@@ -1339,21 +1273,20 @@ function test_pageup()
   -- initially the last two lines are displayed
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_pageup/baseline/screen:1')
+  App.screen.check(y, 'def', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_pageup/baseline/screen:2')
+  App.screen.check(y, 'ghi', 'baseline/screen:2')
   -- after pageup the cursor goes to first line
   edit.run_after_keychord(Editor_state, 'pageup')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_pageup/screen_top')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_pageup/cursor')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor')
   y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_pageup/screen:1')
+  App.screen.check(y, 'abc', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_pageup/screen:2')
+  App.screen.check(y, 'def', 'screen:2')
 end
 
 function test_pageup_scrolls_up_by_screen_line()
-  io.write('\ntest_pageup_scrolls_up_by_screen_line')
   -- display the first three lines with the cursor on the bottom line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1364,26 +1297,25 @@ function test_pageup_scrolls_up_by_screen_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'ghi', 'F - test_pageup_scrolls_up_by_screen_line/baseline/screen:1')
+  App.screen.check(y, 'ghi', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_pageup_scrolls_up_by_screen_line/baseline/screen:2')
+  App.screen.check(y, 'jkl', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_pageup_scrolls_up_by_screen_line/baseline/screen:3')  -- line wrapping includes trailing whitespace
+  App.screen.check(y, 'mno', 'baseline/screen:3')  -- line wrapping includes trailing whitespace
   -- after hitting the page-up key the screen scrolls up to top
   edit.run_after_keychord(Editor_state, 'pageup')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_pageup_scrolls_up_by_screen_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_pageup_scrolls_up_by_screen_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_pageup_scrolls_up_by_screen_line/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'abc ', 'F - test_pageup_scrolls_up_by_screen_line/screen:1')
+  App.screen.check(y, 'abc ', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_pageup_scrolls_up_by_screen_line/screen:2')
+  App.screen.check(y, 'def', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_pageup_scrolls_up_by_screen_line/screen:3')
+  App.screen.check(y, 'ghi', 'screen:3')
 end
 
 function test_pageup_scrolls_up_from_middle_screen_line()
-  io.write('\ntest_pageup_scrolls_up_from_middle_screen_line')
   -- display a few lines starting from the middle of a line (Editor_state.cursor1.pos > 1)
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1394,24 +1326,23 @@ function test_pageup_scrolls_up_from_middle_screen_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'jkl', 'F - test_pageup_scrolls_up_from_middle_screen_line/baseline/screen:2')
+  App.screen.check(y, 'jkl', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_pageup_scrolls_up_from_middle_screen_line/baseline/screen:3')  -- line wrapping includes trailing whitespace
+  App.screen.check(y, 'mno', 'baseline/screen:3')  -- line wrapping includes trailing whitespace
   -- after hitting the page-up key the screen scrolls up to top
   edit.run_after_keychord(Editor_state, 'pageup')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_pageup_scrolls_up_from_middle_screen_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_pageup_scrolls_up_from_middle_screen_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_pageup_scrolls_up_from_middle_screen_line/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'abc ', 'F - test_pageup_scrolls_up_from_middle_screen_line/screen:1')
+  App.screen.check(y, 'abc ', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_pageup_scrolls_up_from_middle_screen_line/screen:2')
+  App.screen.check(y, 'def', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi ', 'F - test_pageup_scrolls_up_from_middle_screen_line/screen:3')
+  App.screen.check(y, 'ghi ', 'screen:3')
 end
 
 function test_enter_on_bottom_line_scrolls_down()
-  io.write('\ntest_enter_on_bottom_line_scrolls_down')
   -- display a few lines with cursor on bottom line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1422,26 +1353,25 @@ function test_enter_on_bottom_line_scrolls_down()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_enter_on_bottom_line_scrolls_down/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_enter_on_bottom_line_scrolls_down/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_enter_on_bottom_line_scrolls_down/baseline/screen:3')
+  App.screen.check(y, 'ghi', 'baseline/screen:3')
   -- after hitting the enter key the screen scrolls down
   edit.run_after_keychord(Editor_state, 'return')
-  check_eq(Editor_state.screen_top1.line, 2, 'F - test_enter_on_bottom_line_scrolls_down/screen_top')
-  check_eq(Editor_state.cursor1.line, 4, 'F - test_enter_on_bottom_line_scrolls_down/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_enter_on_bottom_line_scrolls_down/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 4, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_enter_on_bottom_line_scrolls_down/screen:1')
+  App.screen.check(y, 'def', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'g', 'F - test_enter_on_bottom_line_scrolls_down/screen:2')
+  App.screen.check(y, 'g', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'hi', 'F - test_enter_on_bottom_line_scrolls_down/screen:3')
+  App.screen.check(y, 'hi', 'screen:3')
 end
 
 function test_enter_on_final_line_avoids_scrolling_down_when_not_at_bottom()
-  io.write('\ntest_enter_on_final_line_avoids_scrolling_down_when_not_at_bottom')
   -- display just the bottom line on screen
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1452,20 +1382,19 @@ function test_enter_on_final_line_avoids_scrolling_down_when_not_at_bottom()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'jkl', 'F - test_enter_on_final_line_avoids_scrolling_down_when_not_at_bottom/baseline/screen:1')
+  App.screen.check(y, 'jkl', 'baseline/screen:1')
   -- after hitting the enter key the screen does not scroll down
   edit.run_after_keychord(Editor_state, 'return')
-  check_eq(Editor_state.screen_top1.line, 4, 'F - test_enter_on_final_line_avoids_scrolling_down_when_not_at_bottom/screen_top')
-  check_eq(Editor_state.cursor1.line, 5, 'F - test_enter_on_final_line_avoids_scrolling_down_when_not_at_bottom/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_enter_on_final_line_avoids_scrolling_down_when_not_at_bottom/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 4, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 5, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'j', 'F - test_enter_on_final_line_avoids_scrolling_down_when_not_at_bottom/screen:1')
+  App.screen.check(y, 'j', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'kl', 'F - test_enter_on_final_line_avoids_scrolling_down_when_not_at_bottom/screen:2')
+  App.screen.check(y, 'kl', 'screen:2')
 end
 
 function test_inserting_text_on_final_line_avoids_scrolling_down_when_not_at_bottom()
-  io.write('\ntest_inserting_text_on_final_line_avoids_scrolling_down_when_not_at_bottom')
   -- display just an empty bottom line on screen
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1477,15 +1406,14 @@ function test_inserting_text_on_final_line_avoids_scrolling_down_when_not_at_bot
   edit.draw(Editor_state)
   -- after hitting the inserting_text key the screen does not scroll down
   edit.run_after_text_input(Editor_state, 'a')
-  check_eq(Editor_state.screen_top1.line, 2, 'F - test_inserting_text_on_final_line_avoids_scrolling_down_when_not_at_bottom/screen_top')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_inserting_text_on_final_line_avoids_scrolling_down_when_not_at_bottom/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 2, 'F - test_inserting_text_on_final_line_avoids_scrolling_down_when_not_at_bottom/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
   local y = Editor_state.top
-  App.screen.check(y, 'a', 'F - test_inserting_text_on_final_line_avoids_scrolling_down_when_not_at_bottom/screen:1')
+  App.screen.check(y, 'a', 'screen:1')
 end
 
 function test_typing_on_bottom_line_scrolls_down()
-  io.write('\ntest_typing_on_bottom_line_scrolls_down')
   -- display a few lines with cursor on bottom line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1496,28 +1424,27 @@ function test_typing_on_bottom_line_scrolls_down()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_typing_on_bottom_line_scrolls_down/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_typing_on_bottom_line_scrolls_down/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_typing_on_bottom_line_scrolls_down/baseline/screen:3')
+  App.screen.check(y, 'ghi', 'baseline/screen:3')
   -- after typing something the line wraps and the screen scrolls down
   edit.run_after_text_input(Editor_state, 'j')
   edit.run_after_text_input(Editor_state, 'k')
   edit.run_after_text_input(Editor_state, 'l')
-  check_eq(Editor_state.screen_top1.line, 2, 'F - test_typing_on_bottom_line_scrolls_down/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_typing_on_bottom_line_scrolls_down/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 7, 'F - test_typing_on_bottom_line_scrolls_down/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 7, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_typing_on_bottom_line_scrolls_down/screen:1')
+  App.screen.check(y, 'def', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghij', 'F - test_typing_on_bottom_line_scrolls_down/screen:2')
+  App.screen.check(y, 'ghij', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'kl', 'F - test_typing_on_bottom_line_scrolls_down/screen:3')
+  App.screen.check(y, 'kl', 'screen:3')
 end
 
 function test_left_arrow_scrolls_up_in_wrapped_line()
-  io.write('\ntest_left_arrow_scrolls_up_in_wrapped_line')
   -- display lines starting from second screen line of a line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1529,25 +1456,24 @@ function test_left_arrow_scrolls_up_in_wrapped_line()
   Editor_state.cursor1 = {line=3, pos=5}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'jkl', 'F - test_left_arrow_scrolls_up_in_wrapped_line/baseline/screen:1')
+  App.screen.check(y, 'jkl', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_left_arrow_scrolls_up_in_wrapped_line/baseline/screen:2')
+  App.screen.check(y, 'mno', 'baseline/screen:2')
   -- after hitting the left arrow the screen scrolls up to first screen line
   edit.run_after_keychord(Editor_state, 'left')
   y = Editor_state.top
-  App.screen.check(y, 'ghi ', 'F - test_left_arrow_scrolls_up_in_wrapped_line/screen:1')
+  App.screen.check(y, 'ghi ', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_left_arrow_scrolls_up_in_wrapped_line/screen:2')
+  App.screen.check(y, 'jkl', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_left_arrow_scrolls_up_in_wrapped_line/screen:3')
-  check_eq(Editor_state.screen_top1.line, 3, 'F - test_left_arrow_scrolls_up_in_wrapped_line/screen_top')
-  check_eq(Editor_state.screen_top1.pos, 1, 'F - test_left_arrow_scrolls_up_in_wrapped_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_left_arrow_scrolls_up_in_wrapped_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 4, 'F - test_left_arrow_scrolls_up_in_wrapped_line/cursor:pos')
+  App.screen.check(y, 'mno', 'screen:3')
+  check_eq(Editor_state.screen_top1.line, 3, 'screen_top:line')
+  check_eq(Editor_state.screen_top1.pos, 1, 'screen_top:pos')
+  check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 4, 'cursor:pos')
 end
 
 function test_right_arrow_scrolls_down_in_wrapped_line()
-  io.write('\ntest_right_arrow_scrolls_down_in_wrapped_line')
   -- display the first three lines with the cursor on the bottom line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1559,26 +1485,25 @@ function test_right_arrow_scrolls_down_in_wrapped_line()
   Editor_state.cursor1 = {line=3, pos=5}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_right_arrow_scrolls_down_in_wrapped_line/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_right_arrow_scrolls_down_in_wrapped_line/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi ', 'F - test_right_arrow_scrolls_down_in_wrapped_line/baseline/screen:3')  -- line wrapping includes trailing whitespace
+  App.screen.check(y, 'ghi ', 'baseline/screen:3')  -- line wrapping includes trailing whitespace
   -- after hitting the right arrow the screen scrolls down by one line
   edit.run_after_keychord(Editor_state, 'right')
-  check_eq(Editor_state.screen_top1.line, 2, 'F - test_right_arrow_scrolls_down_in_wrapped_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_right_arrow_scrolls_down_in_wrapped_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 6, 'F - test_right_arrow_scrolls_down_in_wrapped_line/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 6, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_right_arrow_scrolls_down_in_wrapped_line/screen:1')
+  App.screen.check(y, 'def', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi ', 'F - test_right_arrow_scrolls_down_in_wrapped_line/screen:2')
+  App.screen.check(y, 'ghi ', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_right_arrow_scrolls_down_in_wrapped_line/screen:3')
+  App.screen.check(y, 'jkl', 'screen:3')
 end
 
 function test_home_scrolls_up_in_wrapped_line()
-  io.write('\ntest_home_scrolls_up_in_wrapped_line')
   -- display lines starting from second screen line of a line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1590,25 +1515,24 @@ function test_home_scrolls_up_in_wrapped_line()
   Editor_state.cursor1 = {line=3, pos=5}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'jkl', 'F - test_home_scrolls_up_in_wrapped_line/baseline/screen:1')
+  App.screen.check(y, 'jkl', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_home_scrolls_up_in_wrapped_line/baseline/screen:2')
+  App.screen.check(y, 'mno', 'baseline/screen:2')
   -- after hitting home the screen scrolls up to first screen line
   edit.run_after_keychord(Editor_state, 'home')
   y = Editor_state.top
-  App.screen.check(y, 'ghi ', 'F - test_home_scrolls_up_in_wrapped_line/screen:1')
+  App.screen.check(y, 'ghi ', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_home_scrolls_up_in_wrapped_line/screen:2')
+  App.screen.check(y, 'jkl', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_home_scrolls_up_in_wrapped_line/screen:3')
-  check_eq(Editor_state.screen_top1.line, 3, 'F - test_home_scrolls_up_in_wrapped_line/screen_top')
-  check_eq(Editor_state.screen_top1.pos, 1, 'F - test_home_scrolls_up_in_wrapped_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_home_scrolls_up_in_wrapped_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_home_scrolls_up_in_wrapped_line/cursor:pos')
+  App.screen.check(y, 'mno', 'screen:3')
+  check_eq(Editor_state.screen_top1.line, 3, 'screen_top:line')
+  check_eq(Editor_state.screen_top1.pos, 1, 'screen_top:pos')
+  check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
 end
 
 function test_end_scrolls_down_in_wrapped_line()
-  io.write('\ntest_end_scrolls_down_in_wrapped_line')
   -- display the first three lines with the cursor on the bottom line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1620,27 +1544,26 @@ function test_end_scrolls_down_in_wrapped_line()
   Editor_state.cursor1 = {line=3, pos=5}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_end_scrolls_down_in_wrapped_line/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_end_scrolls_down_in_wrapped_line/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi ', 'F - test_end_scrolls_down_in_wrapped_line/baseline/screen:3')  -- line wrapping includes trailing whitespace
+  App.screen.check(y, 'ghi ', 'baseline/screen:3')  -- line wrapping includes trailing whitespace
   -- after hitting end the screen scrolls down by one line
   edit.run_after_keychord(Editor_state, 'end')
-  check_eq(Editor_state.screen_top1.line, 2, 'F - test_end_scrolls_down_in_wrapped_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_end_scrolls_down_in_wrapped_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 8, 'F - test_end_scrolls_down_in_wrapped_line/cursor:pos')
+  check_eq(Editor_state.screen_top1.line, 2, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 8, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_end_scrolls_down_in_wrapped_line/screen:1')
+  App.screen.check(y, 'def', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi ', 'F - test_end_scrolls_down_in_wrapped_line/screen:2')
+  App.screen.check(y, 'ghi ', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_end_scrolls_down_in_wrapped_line/screen:3')
+  App.screen.check(y, 'jkl', 'screen:3')
 end
 
 function test_position_cursor_on_recently_edited_wrapping_line()
   -- draw a line wrapping over 2 screen lines
-  io.write('\ntest_position_cursor_on_recently_edited_wrapping_line')
   App.screen.init{width=100, height=200}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc def ghi jkl mno pqr ', 'xyz'}
@@ -1650,31 +1573,30 @@ function test_position_cursor_on_recently_edited_wrapping_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'abc def ghi ', 'F - test_position_cursor_on_recently_edited_wrapping_line/baseline1/screen:1')
+  App.screen.check(y, 'abc def ghi ', 'baseline1/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl mno pqr ', 'F - test_position_cursor_on_recently_edited_wrapping_line/baseline1/screen:2')
+  App.screen.check(y, 'jkl mno pqr ', 'baseline1/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'xyz', 'F - test_position_cursor_on_recently_edited_wrapping_line/baseline1/screen:3')
+  App.screen.check(y, 'xyz', 'baseline1/screen:3')
   -- add to the line until it's wrapping over 3 screen lines
   edit.run_after_text_input(Editor_state, 's')
   edit.run_after_text_input(Editor_state, 't')
   edit.run_after_text_input(Editor_state, 'u')
-  check_eq(Editor_state.cursor1.pos, 28, 'F - test_position_cursor_on_recently_edited_wrapping_line/cursor:pos')
+  check_eq(Editor_state.cursor1.pos, 28, 'cursor:pos')
   y = Editor_state.top
-  App.screen.check(y, 'abc def ghi ', 'F - test_position_cursor_on_recently_edited_wrapping_line/baseline2/screen:1')
+  App.screen.check(y, 'abc def ghi ', 'baseline2/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl mno pqr ', 'F - test_position_cursor_on_recently_edited_wrapping_line/baseline2/screen:2')
+  App.screen.check(y, 'jkl mno pqr ', 'baseline2/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'stu', 'F - test_position_cursor_on_recently_edited_wrapping_line/baseline2/screen:3')
+  App.screen.check(y, 'stu', 'baseline2/screen:3')
   -- try to move the cursor earlier in the third screen line by clicking the mouse
   edit.run_after_mouse_release(Editor_state, Editor_state.left+8,Editor_state.top+Editor_state.line_height*2+5, 1)
   -- cursor should move
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_position_cursor_on_recently_edited_wrapping_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 26, 'F - test_position_cursor_on_recently_edited_wrapping_line/cursor:pos')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 26, 'cursor:pos')
 end
 
 function test_backspace_can_scroll_up()
-  io.write('\ntest_backspace_can_scroll_up')
   -- display the lines 2/3/4 with the cursor on line 2
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1685,25 +1607,24 @@ function test_backspace_can_scroll_up()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'def', 'F - test_backspace_can_scroll_up/baseline/screen:1')
+  App.screen.check(y, 'def', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_backspace_can_scroll_up/baseline/screen:2')
+  App.screen.check(y, 'ghi', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_backspace_can_scroll_up/baseline/screen:3')
+  App.screen.check(y, 'jkl', 'baseline/screen:3')
   -- after hitting backspace the screen scrolls up by one line
   edit.run_after_keychord(Editor_state, 'backspace')
-  check_eq(Editor_state.screen_top1.line, 1, 'F - test_backspace_can_scroll_up/screen_top')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_backspace_can_scroll_up/cursor')
+  check_eq(Editor_state.screen_top1.line, 1, 'screen_top')
+  check_eq(Editor_state.cursor1.line, 1, 'cursor')
   y = Editor_state.top
-  App.screen.check(y, 'abcdef', 'F - test_backspace_can_scroll_up/screen:1')
+  App.screen.check(y, 'abcdef', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'ghi', 'F - test_backspace_can_scroll_up/screen:2')
+  App.screen.check(y, 'ghi', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'jkl', 'F - test_backspace_can_scroll_up/screen:3')
+  App.screen.check(y, 'jkl', 'screen:3')
 end
 
 function test_backspace_can_scroll_up_screen_line()
-  io.write('\ntest_backspace_can_scroll_up_screen_line')
   -- display lines starting from second screen line of a line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1714,25 +1635,24 @@ function test_backspace_can_scroll_up_screen_line()
   Editor_state.screen_bottom1 = {}
   edit.draw(Editor_state)
   local y = Editor_state.top
-  App.screen.check(y, 'jkl', 'F - test_backspace_can_scroll_up_screen_line/baseline/screen:1')
+  App.screen.check(y, 'jkl', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_backspace_can_scroll_up_screen_line/baseline/screen:2')
+  App.screen.check(y, 'mno', 'baseline/screen:2')
   -- after hitting backspace the screen scrolls up by one screen line
   edit.run_after_keychord(Editor_state, 'backspace')
   y = Editor_state.top
-  App.screen.check(y, 'ghij', 'F - test_backspace_can_scroll_up_screen_line/screen:1')
+  App.screen.check(y, 'ghij', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'kl', 'F - test_backspace_can_scroll_up_screen_line/screen:2')
+  App.screen.check(y, 'kl', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'mno', 'F - test_backspace_can_scroll_up_screen_line/screen:3')
-  check_eq(Editor_state.screen_top1.line, 3, 'F - test_backspace_can_scroll_up_screen_line/screen_top')
-  check_eq(Editor_state.screen_top1.pos, 1, 'F - test_backspace_can_scroll_up_screen_line/screen_top')
-  check_eq(Editor_state.cursor1.line, 3, 'F - test_backspace_can_scroll_up_screen_line/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 4, 'F - test_backspace_can_scroll_up_screen_line/cursor:pos')
+  App.screen.check(y, 'mno', 'screen:3')
+  check_eq(Editor_state.screen_top1.line, 3, 'screen_top:line')
+  check_eq(Editor_state.screen_top1.pos, 1, 'screen_top:pos')
+  check_eq(Editor_state.cursor1.line, 3, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 4, 'cursor:pos')
 end
 
 function test_backspace_past_line_boundary()
-  io.write('\ntest_backspace_past_line_boundary')
   -- position cursor at start of a (non-first) line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1741,14 +1661,13 @@ function test_backspace_past_line_boundary()
   Editor_state.cursor1 = {line=2, pos=1}
   -- backspace joins with previous line
   edit.run_after_keychord(Editor_state, 'backspace')
-  check_eq(Editor_state.lines[1].data, 'abcdef', "F - test_backspace_past_line_boundary")
+  check_eq(Editor_state.lines[1].data, 'abcdef', 'check')
 end
 
 -- some tests for operating over selections created using Shift- chords
 -- we're just testing delete_selection, and it works the same for all keys
 
 function test_backspace_over_selection()
-  io.write('\ntest_backspace_over_selection')
   -- select just one character within a line with cursor before selection
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1758,16 +1677,15 @@ function test_backspace_over_selection()
   Editor_state.selection1 = {line=1, pos=2}
   -- backspace deletes the selected character, even though it's after the cursor
   edit.run_after_keychord(Editor_state, 'backspace')
-  check_eq(Editor_state.lines[1].data, 'bc', "F - test_backspace_over_selection/data")
+  check_eq(Editor_state.lines[1].data, 'bc', 'data')
   -- cursor (remains) at start of selection
-  check_eq(Editor_state.cursor1.line, 1, "F - test_backspace_over_selection/cursor:line")
-  check_eq(Editor_state.cursor1.pos, 1, "F - test_backspace_over_selection/cursor:pos")
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
   -- selection is cleared
-  check_nil(Editor_state.selection1.line, "F - test_backspace_over_selection/selection")
+  check_nil(Editor_state.selection1.line, 'selection')
 end
 
 function test_backspace_over_selection_reverse()
-  io.write('\ntest_backspace_over_selection_reverse')
   -- select just one character within a line with cursor after selection
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1777,16 +1695,15 @@ function test_backspace_over_selection_reverse()
   Editor_state.selection1 = {line=1, pos=1}
   -- backspace deletes the selected character
   edit.run_after_keychord(Editor_state, 'backspace')
-  check_eq(Editor_state.lines[1].data, 'bc', "F - test_backspace_over_selection_reverse/data")
+  check_eq(Editor_state.lines[1].data, 'bc', 'data')
   -- cursor moves to start of selection
-  check_eq(Editor_state.cursor1.line, 1, "F - test_backspace_over_selection_reverse/cursor:line")
-  check_eq(Editor_state.cursor1.pos, 1, "F - test_backspace_over_selection_reverse/cursor:pos")
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
   -- selection is cleared
-  check_nil(Editor_state.selection1.line, "F - test_backspace_over_selection_reverse/selection")
+  check_nil(Editor_state.selection1.line, 'selection')
 end
 
 function test_backspace_over_multiple_lines()
-  io.write('\ntest_backspace_over_multiple_lines')
   -- select just one character within a line with cursor after selection
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1796,17 +1713,16 @@ function test_backspace_over_multiple_lines()
   Editor_state.selection1 = {line=4, pos=2}
   -- backspace deletes the region and joins the remaining portions of lines on either side
   edit.run_after_keychord(Editor_state, 'backspace')
-  check_eq(Editor_state.lines[1].data, 'akl', "F - test_backspace_over_multiple_lines/data:1")
-  check_eq(Editor_state.lines[2].data, 'mno', "F - test_backspace_over_multiple_lines/data:2")
+  check_eq(Editor_state.lines[1].data, 'akl', 'data:1')
+  check_eq(Editor_state.lines[2].data, 'mno', 'data:2')
   -- cursor remains at start of selection
-  check_eq(Editor_state.cursor1.line, 1, "F - test_backspace_over_multiple_lines/cursor:line")
-  check_eq(Editor_state.cursor1.pos, 2, "F - test_backspace_over_multiple_lines/cursor:pos")
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
   -- selection is cleared
-  check_nil(Editor_state.selection1.line, "F - test_backspace_over_multiple_lines/selection")
+  check_nil(Editor_state.selection1.line, 'selection')
 end
 
 function test_backspace_to_end_of_line()
-  io.write('\ntest_backspace_to_end_of_line')
   -- select region from cursor to end of line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1816,17 +1732,16 @@ function test_backspace_to_end_of_line()
   Editor_state.selection1 = {line=1, pos=4}
   -- backspace deletes rest of line without joining to any other line
   edit.run_after_keychord(Editor_state, 'backspace')
-  check_eq(Editor_state.lines[1].data, 'a', "F - test_backspace_to_start_of_line/data:1")
-  check_eq(Editor_state.lines[2].data, 'def', "F - test_backspace_to_start_of_line/data:2")
+  check_eq(Editor_state.lines[1].data, 'a', 'data:1')
+  check_eq(Editor_state.lines[2].data, 'def', 'data:2')
   -- cursor remains at start of selection
-  check_eq(Editor_state.cursor1.line, 1, "F - test_backspace_to_start_of_line/cursor:line")
-  check_eq(Editor_state.cursor1.pos, 2, "F - test_backspace_to_start_of_line/cursor:pos")
+  check_eq(Editor_state.cursor1.line, 1, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 2, 'cursor:pos')
   -- selection is cleared
-  check_nil(Editor_state.selection1.line, "F - test_backspace_to_start_of_line/selection")
+  check_nil(Editor_state.selection1.line, 'selection')
 end
 
 function test_backspace_to_start_of_line()
-  io.write('\ntest_backspace_to_start_of_line')
   -- select region from cursor to start of line
   App.screen.init{width=Editor_state.left+30, height=60}
   Editor_state = edit.initialize_test_state()
@@ -1836,17 +1751,16 @@ function test_backspace_to_start_of_line()
   Editor_state.selection1 = {line=2, pos=3}
   -- backspace deletes beginning of line without joining to any other line
   edit.run_after_keychord(Editor_state, 'backspace')
-  check_eq(Editor_state.lines[1].data, 'abc', "F - test_backspace_to_start_of_line/data:1")
-  check_eq(Editor_state.lines[2].data, 'f', "F - test_backspace_to_start_of_line/data:2")
+  check_eq(Editor_state.lines[1].data, 'abc', 'data:1')
+  check_eq(Editor_state.lines[2].data, 'f', 'data:2')
   -- cursor remains at start of selection
-  check_eq(Editor_state.cursor1.line, 2, "F - test_backspace_to_start_of_line/cursor:line")
-  check_eq(Editor_state.cursor1.pos, 1, "F - test_backspace_to_start_of_line/cursor:pos")
+  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, 'cursor:pos')
   -- selection is cleared
-  check_nil(Editor_state.selection1.line, "F - test_backspace_to_start_of_line/selection")
+  check_nil(Editor_state.selection1.line, 'selection')
 end
 
 function test_undo_insert_text()
-  io.write('\ntest_undo_insert_text')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'xyz'}
@@ -1857,32 +1771,31 @@ function test_undo_insert_text()
   -- insert a character
   edit.draw(Editor_state)
   edit.run_after_text_input(Editor_state, 'g')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_undo_insert_text/baseline/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 5, 'F - test_undo_insert_text/baseline/cursor:pos')
-  check_nil(Editor_state.selection1.line, 'F - test_undo_insert_text/baseline/selection:line')
-  check_nil(Editor_state.selection1.pos, 'F - test_undo_insert_text/baseline/selection:pos')
+  check_eq(Editor_state.cursor1.line, 2, 'baseline/cursor:line')
+  check_eq(Editor_state.cursor1.pos, 5, 'baseline/cursor:pos')
+  check_nil(Editor_state.selection1.line, 'baseline/selection:line')
+  check_nil(Editor_state.selection1.pos, 'baseline/selection:pos')
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_undo_insert_text/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'defg', 'F - test_undo_insert_text/baseline/screen:2')
+  App.screen.check(y, 'defg', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'xyz', 'F - test_undo_insert_text/baseline/screen:3')
+  App.screen.check(y, 'xyz', 'baseline/screen:3')
   -- undo
   edit.run_after_keychord(Editor_state, 'C-z')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_undo_insert_text/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 4, 'F - test_undo_insert_text/cursor:pos')
-  check_nil(Editor_state.selection1.line, 'F - test_undo_insert_text/selection:line')
-  check_nil(Editor_state.selection1.pos, 'F - test_undo_insert_text/selection:pos')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 4, 'cursor:pos')
+  check_nil(Editor_state.selection1.line, 'selection:line')
+  check_nil(Editor_state.selection1.pos, 'selection:pos')
   y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_undo_insert_text/screen:1')
+  App.screen.check(y, 'abc', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_undo_insert_text/screen:2')
+  App.screen.check(y, 'def', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'xyz', 'F - test_undo_insert_text/screen:3')
+  App.screen.check(y, 'xyz', 'screen:3')
 end
 
 function test_undo_delete_text()
-  io.write('\ntest_undo_delete_text')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'defg', 'xyz'}
@@ -1892,35 +1805,34 @@ function test_undo_delete_text()
   Editor_state.screen_bottom1 = {}
   -- delete a character
   edit.run_after_keychord(Editor_state, 'backspace')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_undo_delete_text/baseline/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 4, 'F - test_undo_delete_text/baseline/cursor:pos')
-  check_nil(Editor_state.selection1.line, 'F - test_undo_delete_text/baseline/selection:line')
-  check_nil(Editor_state.selection1.pos, 'F - test_undo_delete_text/baseline/selection:pos')
+  check_eq(Editor_state.cursor1.line, 2, 'baseline/cursor:line')
+  check_eq(Editor_state.cursor1.pos, 4, 'baseline/cursor:pos')
+  check_nil(Editor_state.selection1.line, 'baseline/selection:line')
+  check_nil(Editor_state.selection1.pos, 'baseline/selection:pos')
   local y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_undo_delete_text/baseline/screen:1')
+  App.screen.check(y, 'abc', 'baseline/screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'def', 'F - test_undo_delete_text/baseline/screen:2')
+  App.screen.check(y, 'def', 'baseline/screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'xyz', 'F - test_undo_delete_text/baseline/screen:3')
+  App.screen.check(y, 'xyz', 'baseline/screen:3')
   -- undo
 --?   -- after undo, the backspaced key is selected
   edit.run_after_keychord(Editor_state, 'C-z')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_undo_delete_text/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 5, 'F - test_undo_delete_text/cursor:pos')
-  check_nil(Editor_state.selection1.line, 'F - test_undo_delete_text/selection:line')
-  check_nil(Editor_state.selection1.pos, 'F - test_undo_delete_text/selection:pos')
---?   check_eq(Editor_state.selection1.line, 2, 'F - test_undo_delete_text/selection:line')
---?   check_eq(Editor_state.selection1.pos, 4, 'F - test_undo_delete_text/selection:pos')
+  check_eq(Editor_state.cursor1.line, 2, 'cursor:line')
+  check_eq(Editor_state.cursor1.pos, 5, 'cursor:pos')
+  check_nil(Editor_state.selection1.line, 'selection:line')
+  check_nil(Editor_state.selection1.pos, 'selection:pos')
+--?   check_eq(Editor_state.selection1.line, 2, 'selection:line')
+--?   check_eq(Editor_state.selection1.pos, 4, 'selection:pos')
   y = Editor_state.top
-  App.screen.check(y, 'abc', 'F - test_undo_delete_text/screen:1')
+  App.screen.check(y, 'abc', 'screen:1')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'defg', 'F - test_undo_delete_text/screen:2')
+  App.screen.check(y, 'defg', 'screen:2')
   y = y + Editor_state.line_height
-  App.screen.check(y, 'xyz', 'F - test_undo_delete_text/screen:3')
+  App.screen.check(y, 'xyz', 'screen:3')
 end
 
 function test_undo_restores_selection()
-  io.write('\ntest_undo_restores_selection')
   -- display a line of text with some part selected
   App.screen.init{width=75, height=80}
   Editor_state = edit.initialize_test_state()
@@ -1933,18 +1845,17 @@ function test_undo_restores_selection()
   edit.draw(Editor_state)
   -- delete selected text
   edit.run_after_text_input(Editor_state, 'x')
-  check_eq(Editor_state.lines[1].data, 'xbc', 'F - test_undo_restores_selection/baseline')
-  check_nil(Editor_state.selection1.line, 'F - test_undo_restores_selection/baseline:selection')
+  check_eq(Editor_state.lines[1].data, 'xbc', 'baseline')
+  check_nil(Editor_state.selection1.line, 'baseline:selection')
   -- undo
   edit.run_after_keychord(Editor_state, 'C-z')
   edit.run_after_keychord(Editor_state, 'C-z')
   -- selection is restored
-  check_eq(Editor_state.selection1.line, 1, 'F - test_undo_restores_selection/line')
-  check_eq(Editor_state.selection1.pos, 2, 'F - test_undo_restores_selection/pos')
+  check_eq(Editor_state.selection1.line, 1, 'line')
+  check_eq(Editor_state.selection1.pos, 2, 'pos')
 end
 
 function test_search()
-  io.write('\ntest_search')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc', 'def', 'ghi', 'deg'}
@@ -1957,8 +1868,8 @@ function test_search()
   edit.run_after_keychord(Editor_state, 'C-f')
   edit.run_after_text_input(Editor_state, 'd')
   edit.run_after_keychord(Editor_state, 'return')
-  check_eq(Editor_state.cursor1.line, 2, 'F - test_search/1/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_search/1/cursor:pos')
+  check_eq(Editor_state.cursor1.line, 2, '1/cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, '1/cursor:pos')
   -- reset cursor
   Editor_state.cursor1 = {line=1, pos=1}
   Editor_state.screen_top1 = {line=1, pos=1}
@@ -1967,12 +1878,11 @@ function test_search()
   edit.run_after_text_input(Editor_state, 'de')
   edit.run_after_keychord(Editor_state, 'down')
   edit.run_after_keychord(Editor_state, 'return')
-  check_eq(Editor_state.cursor1.line, 4, 'F - test_search/2/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_search/2/cursor:pos')
+  check_eq(Editor_state.cursor1.line, 4, '2/cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, '2/cursor:pos')
 end
 
 function test_search_upwards()
-  io.write('\ntest_search_upwards')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc abd'}
@@ -1986,12 +1896,11 @@ function test_search_upwards()
   edit.run_after_text_input(Editor_state, 'a')
   -- search for previous occurrence
   edit.run_after_keychord(Editor_state, 'up')
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_search_upwards/2/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_search_upwards/2/cursor:pos')
+  check_eq(Editor_state.cursor1.line, 1, '2/cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, '2/cursor:pos')
 end
 
 function test_search_wrap()
-  io.write('\ntest_search_wrap')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc'}
@@ -2005,12 +1914,11 @@ function test_search_wrap()
   edit.run_after_text_input(Editor_state, 'a')
   edit.run_after_keychord(Editor_state, 'return')
   -- cursor wraps
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_search_wrap/1/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 1, 'F - test_search_wrap/1/cursor:pos')
+  check_eq(Editor_state.cursor1.line, 1, '1/cursor:line')
+  check_eq(Editor_state.cursor1.pos, 1, '1/cursor:pos')
 end
 
 function test_search_wrap_upwards()
-  io.write('\ntest_search_wrap_upwards')
   App.screen.init{width=120, height=60}
   Editor_state = edit.initialize_test_state()
   Editor_state.lines = load_array{'abc abd'}
@@ -2024,6 +1932,6 @@ function test_search_wrap_upwards()
   edit.run_after_text_input(Editor_state, 'a')
   edit.run_after_keychord(Editor_state, 'up')
   -- cursor wraps
-  check_eq(Editor_state.cursor1.line, 1, 'F - test_search_wrap_upwards/1/cursor:line')
-  check_eq(Editor_state.cursor1.pos, 5, 'F - test_search_wrap_upwards/1/cursor:pos')
+  check_eq(Editor_state.cursor1.line, 1, '1/cursor:line')
+  check_eq(Editor_state.cursor1.pos, 5, '1/cursor:pos')
 end