fix: ensure all timers are cancelled when after staggered race finishes

pyproject.toml

@@ -82,6 +82,8 @@ prerelease = true
 [tool.pytest.ini_options]
 addopts = "-v -Wdefault --cov=aiohappyeyeballs --cov-report=term-missing:skip-covered"
 pythonpath = ["src"]
+asyncio_mode = "auto"
+asyncio_default_fixture_loop_scope = "function"
 
 [tool.coverage.run]
 branch = true

src/aiohappyeyeballs/_staggered.py

@@ -156,9 +156,9 @@ async def run_one_coro(
                 # so we have no winner and all coroutines failed.
                 break
 
-            while tasks:
+            while tasks or start_next:
                 done = await _wait_one(
-                    [*tasks, start_next] if start_next else tasks, loop
+                    (*tasks, start_next) if start_next else tasks, loop
                 )
                 if done is start_next:
                     # The current task has failed or the timer has expired

tests/conftest.py

@@ -1,7 +1,10 @@
 """Configuration for the tests."""
 
 import asyncio
+import reprlib
 import threading
+from asyncio.events import AbstractEventLoop, TimerHandle
+from contextlib import contextmanager
 from typing import Generator
 
 import pytest
@@ -16,6 +19,27 @@ def verify_threads_ended():
     assert not threads
 
 
+def get_scheduled_timer_handles(loop: AbstractEventLoop) -> list[TimerHandle]:
+    """Return a list of scheduled TimerHandles."""
+    handles: list[TimerHandle] = loop._scheduled  # type: ignore[attr-defined]
+    return handles
+
+
+@contextmanager
+def long_repr_strings() -> Generator[None]:
+    """Increase reprlib maxstring and maxother to 300."""
+    arepr = reprlib.aRepr
+    original_maxstring = arepr.maxstring
+    original_maxother = arepr.maxother
+    arepr.maxstring = 300
+    arepr.maxother = 300
+    try:
+        yield
+    finally:
+        arepr.maxstring = original_maxstring
+        arepr.maxother = original_maxother
+
+
 @pytest.fixture(autouse=True)
 def verify_no_lingering_tasks(
     event_loop: asyncio.AbstractEventLoop,
@@ -30,3 +54,9 @@ def verify_no_lingering_tasks(
         task.cancel()
     if tasks:
         event_loop.run_until_complete(asyncio.wait(tasks))
+
+    for handle in get_scheduled_timer_handles(event_loop):
+        if not handle.cancelled():
+            with long_repr_strings():
+                pytest.fail(f"Lingering timer after test {handle!r}")
+                handle.cancel()