add `alignTable`, `parseTableCells` to align/format a tab(etc) delimited table (#10182)

* add compiler/unittest_light.nim for easy diffing: assertEquals and mismatch
* fixup
* add alignTable, parseTableCells

3 files changed, 171 insertions, 0 deletions

diff --git a/tests/compiler/nim.cfg b/tests/compiler/nim.cfg
new file mode 100644
index 000000000..6f49473aa
--- /dev/null
+++ b/tests/compiler/nim.cfg
@@ -0,0 +1,7 @@
+# note: consider moving tests/compilerapi/ to tests/compiler/ since
+# that's more predictable.
+
+# note: without this, tests may succeed locally but fail on CI (it can succeed
+# locally even when compiling via `./bin/nim` because `$HOME/.nimble` is being
+# used).
+--path:"../../" # so we can `import compiler/foo` in this dir
diff --git a/tests/compiler/tasciitables.nim b/tests/compiler/tasciitables.nim
new file mode 100644
index 000000000..0a5ee0f05
--- /dev/null
+++ b/tests/compiler/tasciitables.nim
@@ -0,0 +1,109 @@
+import compiler/unittest_light
+import compiler/asciitables
+
+import strformat
+
+proc alignTableCustom(s: string, delim = '\t', sep = ","): string =
+  for cell in parseTableCells(s, delim):
+    result.add fmt"({cell.row},{cell.col}): "
+    for i in cell.text.len..<cell.width:
+      result.add " "
+    result.add cell.text
+    if cell.col < cell.ncols-1:
+      result.add sep
+    if cell.col == cell.ncols-1 and cell.row < cell.nrows - 1:
+      result.add '\n'
+
+proc testAlignTable() =
+  block: # test with variable width columns
+    var ret = ""
+    ret.add "12\t143\tbcdef\n"
+    ret.add "2\t14394852020\tbcdef\n"
+    ret.add "45342\t1\tbf\n"
+    ret.add "45342\t1\tbsadfasdfasfdasdff\n"
+    ret.add "453232323232342\t1\tbsadfasdfasfdasdff\n"
+    ret.add "45342\t1\tbf\n"
+    ret.add "45342\t1\tb afasf a ff\n"
+    ret.add "4\t1\tbf\n"
+
+    assertEquals alignTable(ret),
+      """
+12              143         bcdef             
+2               14394852020 bcdef             
+45342           1           bf                
+45342           1           bsadfasdfasfdasdff
+453232323232342 1           bsadfasdfasfdasdff
+45342           1           bf                
+45342           1           b afasf a ff      
+4               1           bf                
+"""
+
+    assertEquals alignTable(ret, fill = '.', sep = ","),
+      """
+12.............,143........,bcdef.............
+2..............,14394852020,bcdef.............
+45342..........,1..........,bf................
+45342..........,1..........,bsadfasdfasfdasdff
+453232323232342,1..........,bsadfasdfasfdasdff
+45342..........,1..........,bf................
+45342..........,1..........,b afasf a ff......
+4..............,1..........,bf................
+"""
+
+    assertEquals alignTableCustom(ret, sep = "  "),
+      """
+(0,0):              12  (0,1):         143  (0,2):              bcdef
+(1,0):               2  (1,1): 14394852020  (1,2):              bcdef
+(2,0):           45342  (2,1):           1  (2,2):                 bf
+(3,0):           45342  (3,1):           1  (3,2): bsadfasdfasfdasdff
+(4,0): 453232323232342  (4,1):           1  (4,2): bsadfasdfasfdasdff
+(5,0):           45342  (5,1):           1  (5,2):                 bf
+(6,0):           45342  (6,1):           1  (6,2):       b afasf a ff
+(7,0):               4  (7,1):           1  (7,2):                 bf
+"""
+
+  block: # test with 1 column
+    var ret = "12\nasdfa\nadf"
+    assertEquals alignTable(ret), """
+12   
+asdfa
+adf  """
+
+  block: # test with empty input
+    var ret = ""
+    assertEquals alignTable(ret), ""
+
+  block: # test with 1 row
+    var ret = "abc\tdef"
+    assertEquals alignTable(ret), """
+abc def"""
+
+  block: # test with 1 row ending in \t
+    var ret = "abc\tdef\t"
+    assertEquals alignTable(ret), """
+abc def """
+
+  block: # test with 1 row starting with \t
+    var ret = "\tabc\tdef\t"
+    assertEquals alignTable(ret), """
+ abc def """
+
+
+  block: # test with variable number of cols per row
+    var ret = """
+a1,a2,a3
+
+b1
+c1,c2
+,d1
+"""
+    assertEquals alignTableCustom(ret, delim = ',', sep = ","),
+      """
+(0,0): a1,(0,1): a2,(0,2): a3
+(1,0):   ,(1,1):   ,(1,2):   
+(2,0): b1,(2,1):   ,(2,2):   
+(3,0): c1,(3,1): c2,(3,2):   
+(4,0):   ,(4,1): d1,(4,2):   
+"""
+
+testAlignTable()
diff --git a/tests/compiler/tunittest_light.nim b/tests/compiler/tunittest_light.nim
new file mode 100644
index 000000000..d20293d5b
--- /dev/null
+++ b/tests/compiler/tunittest_light.nim
@@ -0,0 +1,55 @@
+import compiler/unittest_light
+
+proc testAssertEquals() =
+  assertEquals("foo", "foo")
+  doAssertRaises(AssertionError):
+    assertEquals("foo", "foo ")
+
+proc testMismatch() =
+  assertEquals(1+1, 2*1)
+
+  let a = """
+  some test with space at the end of lines    
+
+  can be hard to spot differences when diffing in a terminal   
+  without this helper function
+
+"""
+
+  let b = """
+  some test with space at the end of lines    
+
+  can be hard to spot differences when diffing in a terminal  
+  without this helper function
+
+"""
+
+  doAssert mismatch(a, b) == """
+
+lhs:{
+  some test with space at the end of lines    \n
+\n
+  can be hard to spot differences when diffing in a terminal   \n
+  without this helper function\n
+\n
+}
+rhs:{
+  some test with space at the end of lines    \n
+\n
+  can be hard to spot differences when diffing in a terminal  \n
+  without this helper function\n
+\n
+}
+lhs.len: 144 rhs.len: 143
+first mismatch index: 110
+lhs[i]: {" "} rhs[i]: {"\n"}lhs[0..<i]:{
+  some test with space at the end of lines    \n
+\n
+  can be hard to spot differences when diffing in a terminal  }
+rhs[0..<i]:{
+  some test with space at the end of lines    \n
+\n
+  can be hard to spot differences when diffing in a terminal  }"""
+
+testMismatch()
+testAssertEquals()