From 05eb6dec47d2bedc5c5b1edc83b35e579aa44f0e Mon Sep 17 00:00:00 2001
From: twisteroid ambassador <twisteroidambassador@users.noreply.github.com>
Date: Tue, 18 Oct 2022 03:06:05 +0800
Subject: [PATCH] Add a non-random test to test_stagger.py.

This test fails, but not very reliably.
The cause of failure is that `asyncio.wait_for` sometimes swallows cancellation:
https://github.com/python/cpython/issues/86296
---
 async_stagger/test_stagger.py | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/async_stagger/test_stagger.py b/async_stagger/test_stagger.py
index 6d46cab..4e0ad73 100644
--- a/async_stagger/test_stagger.py
+++ b/async_stagger/test_stagger.py
@@ -14,6 +14,30 @@
 from .aitertools import aiter_from_iter
 
 
+@pytest.mark.asyncio
+async def test_simultaneous_done_fail():
+    for _ in range(50):
+        await simultaneous_done_fail()
+
+
+async def simultaneous_done_fail():
+    async def first():
+        await asyncio.sleep(0.3)
+        return 1
+
+    async def second():
+        await asyncio.sleep(0.1)
+        raise RuntimeError('2')
+
+    async def third():
+        await asyncio.sleep(0.05)
+        return 3
+
+    coro_fns = aiter_from_iter((first, second, third))
+
+    winner_result, winner_idx, exc, aiter_exc = await staggered_race(coro_fns, 0.2)
+
+
 @pytest.mark.asyncio
 async def test_stagger_random_tasks():
     for _ in range(10):