bpo-38013: make async_generator_athrow object tolerant to throwing exceptions (GH-16070)
Even when the helper is not started yet.
This behavior follows conventional generator one.
There is no reason for `async_generator_athrow` to handle `gen.throw()` differently.
https://bugs.python.org/issue38013
(cherry picked from commit c275312a6284bd319ea33c9abd7e15c230eca43f)
Co-authored-by: Andrew Svetlov <andrew.svetlov@gmail.com>
diff --git a/Lib/test/test_asyncgen.py b/Lib/test/test_asyncgen.py
index 71b0968..3a8d5fd 100644
--- a/Lib/test/test_asyncgen.py
+++ b/Lib/test/test_asyncgen.py
@@ -1125,6 +1125,28 @@
res = self.loop.run_until_complete(run())
self.assertEqual(res, [i * 2 for i in range(1, 10)])
+ def test_asyncgen_nonstarted_hooks_are_cancellable(self):
+ # See https://bugs.python.org/issue38013
+ messages = []
+
+ def exception_handler(loop, context):
+ messages.append(context)
+
+ async def async_iterate():
+ yield 1
+ yield 2
+
+ async def main():
+ loop = asyncio.get_running_loop()
+ loop.set_exception_handler(exception_handler)
+
+ async for i in async_iterate():
+ break
+
+ asyncio.run(main())
+
+ self.assertEqual([], messages)
+
if __name__ == "__main__":
unittest.main()