add exception handling shim for Chronos V4

asynctest/templates.nim

@@ -1,3 +1,18 @@
+template launderExceptions(body: typed) =
+  ## Chronos V4 requires that all procs which raise Exception annotate it
+  ## with {.async: (raises: [Exception]).}, but this construct does not
+  ## exist in asyncdispatch. We therefore launder all real instances of
+  ## Exception into CatchableError and make Chronos happy while not losing
+  ## context information for the remainder of the exception types.
+  try:
+    body
+  except Defect as ex:
+    raise ex
+  except CatchableError as ex:
+    raise ex
+  except Exception as ex:
+    raise newException(CatchableError, ex.msg, ex)
+
 template suite*(name, body) =
 
   suite name:
@@ -10,18 +25,18 @@ template suite*(name, body) =
     ## Runs after all tests in the suite
     template teardownAll(teardownAllBody) {.used.} =
       template teardownAllIMPL: untyped {.inject.} =
-        let a = proc {.async.} = teardownAllBody
+        let a = proc {.async.} = launderExceptions: teardownAllBody
         waitFor a()
 
     template setup(setupBody) {.used.} =
       setup:
-        let asyncproc = proc {.async.} = setupBody
+        let asyncproc = proc {.async.} = launderExceptions: setupBody
         waitFor asyncproc()
 
     template teardown(teardownBody) {.used.} =
       teardown:
         let exception = getCurrentException()
-        let asyncproc = proc {.async.} = teardownBody
+        let asyncproc = proc {.async.} = launderExceptions: teardownBody
         waitFor asyncproc()
         setCurrentException(exception)
 
@@ -35,5 +50,5 @@ template suite*(name, body) =
 
 template test*(name, body) =
   test name:
-    let asyncproc = proc {.async.} = body
+    let asyncproc = proc {.async.} = launderExceptions: body
     waitFor asyncproc()

testmodules/unittest2/test.nimble

@@ -3,7 +3,7 @@ author = "Asynctest Authors"
 description = "Asynctest tests for pkg/unittest2 and pkg/chronos"
 license = "MIT"
 
-requires "unittest2"
+requires "unittest2 <= 0.0.9"
 requires "chronos"
 
 task test, "Runs the test suite":