code review

python · kumaraditya303 · Feb 16, 2023 · Sep 12, 2022 · Oct 21, 2022 · Oct 21, 2022
commit 9b0ef93407dd90359c1fc081e472705efc02f0f0
@@ -438,9 +438,16 @@ async def wait_for(fut, timeout):
 
     If the wait is cancelled, the task is also cancelled.
 
+    If the task supresses the cancellation and returns a value instead,
+    that value is returned.
+
     This function is a coroutine.
     """
 
+    # When timeout <= 0, `asyncio.timeout` raises `TimeoutError`
+    # whereas `wait_for` disables the timeout so we special case
+    # it here to preserve the behavior.
+
     if timeout is not None and timeout <= 0:
         fut = ensure_future(fut)
 

@@ -87,7 +87,8 @@ async def func():
             return asyncio.all_tasks()
 
         # The repr() call should not raise RecursionError at first.
-        repr(await asyncio.wait_for(func(), timeout=10))
+        waiter = await asyncio.wait_for(asyncio.Task(func()),timeout=10)
+        self.assertIn('...', repr(waiter))
 
 
 if __name__ == '__main__':

@@ -263,8 +263,10 @@ async def test_cancel_wait_for(self):
         await self._test_cancel_wait_for(60.0)
 
     async def test_wait_for_cancel_suppressed(self):
-        # See https://github.com/python/cpython/issues/84849
-        # See https://github.com/python/cpython/pull/28149
+        # GH-86296: Supressing CancelledError is discouraged
+        # but if a task subpresses CancelledError and returns a value,
+        # `wait_for` should return the value instead of raising CancelledError.
+        # This is the same behavior as `asyncio.timeout`.
 
         async def return_42():
             try: