Address review feedback: use asyncio.Lock as fallback when anyio is not available and improve test types

Author: proboscis

returns/primitives/reawaitable.py

@@ -2,7 +2,13 @@
 from functools import wraps
 from typing import NewType, ParamSpec, TypeVar, cast, final
 
-import anyio
+# Try to use anyio.Lock, fall back to asyncio.Lock
+try:
+    import anyio
+    Lock = anyio.Lock
+except ImportError:
+    import asyncio
+    Lock = asyncio.Lock
 
 _ValueType = TypeVar('_ValueType')
 _AwaitableT = TypeVar('_AwaitableT', bound=Awaitable)
@@ -54,7 +60,7 @@ class ReAwaitable:
 
     def __init__(self, coro: Awaitable[_ValueType]) -> None:
         """We need just an awaitable to work with."""
-        self._lock = anyio.Lock()
+        self._lock = Lock()
         self._coro = coro
         self._cache: _ValueType | _Sentinel = _sentinel
 

tests/test_primitives/test_reawaitable/test_reawaitable_concurrency.py

@@ -4,18 +4,21 @@
 from returns.primitives.reawaitable import ReAwaitable, reawaitable
 
 
-async def sample_coro():
-    await anyio.sleep(0.1)
+# Fix for issue with multiple awaits on the same ReAwaitable instance
+# causing race conditions: https://github.com/dry-python/returns/issues/2048
+async def sample_coro() -> str:
+    """Sample coroutine for testing."""
+    await anyio.sleep(1)  # Increased from 0.1 to reduce chance of random failures
     return 'done'
 
 
-async def await_helper(awaitable_obj):
+async def await_helper(awaitable_obj) -> str:
     """Helper to await objects in tasks."""
     return await awaitable_obj
 
 
 @pytest.mark.anyio
-async def test_concurrent_awaitable():
+async def test_concurrent_awaitable() -> None:
     """Test that ReAwaitable works with concurrent awaits."""
     test_target = ReAwaitable(sample_coro())
 
@@ -25,11 +28,11 @@ async def test_concurrent_awaitable():
 
 
 @pytest.mark.anyio  # noqa: WPS210
-async def test_reawaitable_decorator():
+async def test_reawaitable_decorator() -> None:
     """Test the reawaitable decorator with concurrent awaits."""
 
-    async def test_coro():  # noqa: WPS430
-        await anyio.sleep(0.1)
+    async def test_coro() -> str:  # noqa: WPS430
+        await anyio.sleep(1)  # Increased from 0.1 to reduce chance of random failures
         return "decorated"
 
     decorated = reawaitable(test_coro)
@@ -49,10 +52,10 @@ async def test_coro():  # noqa: WPS430
 
 
 @pytest.mark.anyio
-async def test_reawaitable_repr():
+async def test_reawaitable_repr() -> None:
     """Test the __repr__ method of ReAwaitable."""
 
-    async def test_func():  # noqa: WPS430
+    async def test_func() -> int:  # noqa: WPS430
         return 1
 
     coro = test_func()