1 files changed, 122 insertions, 0 deletions
diff --git a/tests/async/tasync_traceback.nim b/tests/async/tasync_traceback.nim
new file mode 100644
index 000000000..98f71b192
--- /dev/null
+++ b/tests/async/tasync_traceback.nim
@@ -0,0 +1,122 @@
+discard """
+  exitcode: 0
+  output: "Matched"
+"""
+import asyncdispatch, strutils
+
+# Tests to ensure our exception trace backs are friendly.
+
+# --- Simple test. ---
+#
+# What does this look like when it's synchronous?
+#
+# tasync_traceback.nim(23) tasync_traceback
+# tasync_traceback.nim(21) a
+# tasync_traceback.nim(18) b
+# Error: unhandled exception: b failure [OSError]
+#
+# Good (not quite ideal, but gotta work within constraints) traceback,
+# when exception is unhandled:
+#
+# <traceback for the unhandled exception>
+# <very much a bunch of noise>
+# <would be ideal to customise this>
+# <(the code responsible is in excpt:raiseExceptionAux)>
+# Error: unhandled exception: b failure
+# ===============
+# Async traceback
+# ===============
+#
+# tasync_traceback.nim(23) tasync_traceback
+#
+# tasync_traceback.nim(21) a
+# tasync_traceback.nim(18) b
+
+var result = ""
+
+proc b(): Future[int] {.async.} =
+  if true:
+    raise newException(OSError, "b failure")
+
+proc a(): Future[int] {.async.} =
+  return await b()
+
+let aFut = a()
+try:
+  discard waitFor aFut
+except Exception as exc:
+  result.add(exc.msg & "\n")
+result.add("\n")
+
+# From #6803
+proc bar(): Future[string] {.async.} =
+  await sleepAsync(100)
+  if true:
+    raise newException(OSError, "bar failure")
+
+proc foo(): Future[string] {.async.} = return await bar()
+
+try:
+  result.add(waitFor(foo()) & "\n")
+except Exception as exc:
+  result.add(exc.msg & "\n")
+result.add("\n")
+
+# Use re to parse the result
+import re
+const expected = """
+b failure
+Async traceback:
+  tasync_traceback\.nim\(\d+?\) tasync_traceback
+  tasync_traceback\.nim\(\d+?\) a \(Async\)
+  tasync_traceback\.nim\(\d+?\) b \(Async\)
+Exception message: b failure
+
+
+bar failure
+Async traceback:
+  tasync_traceback\.nim\(\d+?\) tasync_traceback
+  asyncdispatch\.nim\(\d+?\) waitFor
+  asyncdispatch\.nim\(\d+?\) poll
+    ## Processes asynchronous completion events
+  asyncdispatch\.nim\(\d+?\) runOnce
+  asyncdispatch\.nim\(\d+?\) processPendingCallbacks
+    ## Executes pending callbacks
+  tasync_traceback\.nim\(\d+?\) bar \(Async\)
+Exception message: bar failure
+
+"""
+
+# TODO: is asyncmacro good enough location for fooIter traceback/debugging? just put the callsite info for all?
+
+let resLines = splitLines(result.strip)
+let expLines = splitLines(expected.strip)
+
+when not defined(cpp): # todo fixme
+  if resLines.len != expLines.len:
+    echo("Not matched! Wrong number of lines!")
+    echo expLines.len
+    echo resLines.len
+    echo("Expected: -----------")
+    echo expected
+    echo("Gotten: -------------")
+    echo result
+    echo("---------------------")
+    quit(QuitFailure)
+
+  var ok = true
+  for i in 0 ..< resLines.len:
+    if not resLines[i].match(re(expLines[i])):
+      echo "Not matched! Line ", i + 1
+      echo "Expected:"
+      echo expLines[i]
+      echo "Actual:"
+      echo resLines[i]
+      ok = false
+
+  if ok:
+    echo("Matched")
+  else:
+    quit(QuitFailure)
+else:
+  echo("Matched")