asyncio: Error if awaiting in parallel on the same coroutine

See https://github.com/python/asyncio/pull/293 for details.

1 files changed, 20 insertions, 0 deletions

diff --git a/Lib/test/test_asyncio/test_pep492.py b/Lib/test/test_asyncio/test_pep492.py
index 41e1b8a..404a748 100644
--- a/Lib/test/test_asyncio/test_pep492.py
+++ b/Lib/test/test_asyncio/test_pep492.py
@@ -203,6 +203,26 @@ class CoroutineTests(BaseTest):
 
         self.loop.run_until_complete(runner())
 
+    def test_double_await(self):
+        async def afunc():
+            await asyncio.sleep(0.1, loop=self.loop)
+
+        async def runner():
+            coro = afunc()
+            t = asyncio.Task(coro, loop=self.loop)
+            try:
+                await asyncio.sleep(0, loop=self.loop)
+                await coro
+            finally:
+                t.cancel()
+
+        self.loop.set_debug(True)
+        with self.assertRaisesRegex(
+            RuntimeError,
+            r'Cannot await.*test_double_await.*\bafunc\b.*while.*\bsleep\b'):
+
+            self.loop.run_until_complete(runner())
+
 
 if __name__ == '__main__':
     unittest.main()