bpo-36829: Add test.support.catch_unraisable_exception() (GH-13490)

* Copy test_exceptions.test_unraisable() to
  test_sys.UnraisableHookTest().
* Use catch_unraisable_exception() in test_coroutines,
  test_exceptions, test_generators.

1 files changed, 12 insertions, 5 deletions

diff --git a/Lib/test/test_coroutines.py b/Lib/test/test_coroutines.py
index 8443e65..036f13f 100644
--- a/Lib/test/test_coroutines.py
+++ b/Lib/test/test_coroutines.py
@@ -2342,12 +2342,19 @@ class OriginTrackingTest(unittest.TestCase):
         orig_wuc = warnings._warn_unawaited_coroutine
         try:
             warnings._warn_unawaited_coroutine = lambda coro: 1/0
-            with support.captured_stderr() as stream:
-                corofn()
+            with support.catch_unraisable_exception() as cm, \
+                 support.captured_stderr() as stream:
+                # only store repr() to avoid keeping the coroutine alive
+                coro = corofn()
+                coro_repr = repr(coro)
+
+                # clear reference to the coroutine without awaiting for it
+                del coro
                 support.gc_collect()
-            self.assertIn("Exception ignored in", stream.getvalue())
-            self.assertIn("ZeroDivisionError", stream.getvalue())
-            self.assertIn("was never awaited", stream.getvalue())
+
+                self.assertEqual(repr(cm.unraisable.object), coro_repr)
+                self.assertEqual(cm.unraisable.exc_type, ZeroDivisionError)
+                self.assertIn("was never awaited", stream.getvalue())
 
             del warnings._warn_unawaited_coroutine
             with support.captured_stderr() as stream: