bpo-39386: Prevent double awaiting of async iterator (GH-18081)
(cherry picked from commit a96e06db77dcbd3433d39761ddb4615d7d96284a)
Co-authored-by: Andrew Svetlov <andrew.svetlov@gmail.com>
diff --git a/Lib/test/test_asyncgen.py b/Lib/test/test_asyncgen.py
index 58d8aee..24b20be 100644
--- a/Lib/test/test_asyncgen.py
+++ b/Lib/test/test_asyncgen.py
@@ -1128,6 +1128,42 @@
self.assertEqual([], messages)
+ def test_async_gen_await_anext_twice(self):
+ async def async_iterate():
+ yield 1
+ yield 2
+
+ async def run():
+ it = async_iterate()
+ nxt = it.__anext__()
+ await nxt
+ with self.assertRaisesRegex(
+ RuntimeError,
+ r"cannot reuse already awaited __anext__\(\)/asend\(\)"
+ ):
+ await nxt
+
+ await it.aclose() # prevent unfinished iterator warning
+
+ self.loop.run_until_complete(run())
+
+ def test_async_gen_await_aclose_twice(self):
+ async def async_iterate():
+ yield 1
+ yield 2
+
+ async def run():
+ it = async_iterate()
+ nxt = it.aclose()
+ await nxt
+ with self.assertRaisesRegex(
+ RuntimeError,
+ r"cannot reuse already awaited aclose\(\)/athrow\(\)"
+ ):
+ await nxt
+
+ self.loop.run_until_complete(run())
+
if __name__ == "__main__":
unittest.main()