chore: import upstream snapshot with attribution

tests/test_asyncio_utils.py

@@ -0,0 +1,62 @@
+from __future__ import annotations
+
+import asyncio
+from collections.abc import Coroutine
+from typing import Any
+
+import pytest
+
+from opensquilla.asyncio_utils import create_background_task
+
+
+async def _return_value(value: str) -> str:
+    return value
+
+
+@pytest.mark.asyncio
+async def test_create_background_task_returns_real_task() -> None:
+    task = create_background_task(_return_value("done"))
+
+    assert isinstance(task, asyncio.Task)
+    assert await task == "done"
+
+
+@pytest.mark.asyncio
+async def test_create_background_task_closes_unconsumed_coroutine_for_stubbed_non_task(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    sentinel = object()
+
+    def fake_create_task(coro: Coroutine[Any, Any, Any]) -> object:
+        return sentinel
+
+    monkeypatch.setattr(asyncio, "create_task", fake_create_task)
+
+    coro = _return_value("unused")
+    assert coro.cr_frame is not None
+
+    result = create_background_task(coro)
+
+    assert result is sentinel
+    assert coro.cr_frame is None
+
+
+@pytest.mark.asyncio
+async def test_create_background_task_closes_unconsumed_coroutine_when_create_task_raises(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    class CreateTaskError(RuntimeError):
+        pass
+
+    def fake_create_task(coro: Coroutine[Any, Any, Any]) -> object:
+        raise CreateTaskError("task creation failed")
+
+    monkeypatch.setattr(asyncio, "create_task", fake_create_task)
+
+    coro = _return_value("unused")
+    assert coro.cr_frame is not None
+
+    with pytest.raises(CreateTaskError, match="task creation failed"):
+        create_background_task(coro)
+
+    assert coro.cr_frame is None