type hint non-suppressing contexts (closes #143)

Author: maxfischer2781

asyncstdlib/asynctools.py

@@ -110,10 +110,9 @@ async def __aenter__(self) -> AsyncIterator[T]:
         self._borrowed_iter = _ScopedAsyncIterator(self._iterator)
         return self._borrowed_iter
 
-    async def __aexit__(self, *args: Any) -> bool:
+    async def __aexit__(self, *args: Any) -> None:
         await self._borrowed_iter._aclose_wrapper()  # type: ignore
         await self._iterator.aclose()  # type: ignore
-        return False
 
     def __repr__(self) -> str:
         return f"<{self.__class__.__name__} of {self._iterator!r} at 0x{(id(self)):x}>"

asyncstdlib/contextlib.py

@@ -199,9 +199,8 @@ def __init__(self, thing: AClose):
     async def __aenter__(self) -> AClose:
         return self.thing
 
-    async def __aexit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> bool:
+    async def __aexit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> None:
         await self.thing.aclose()
-        return False
 
 
 closing = Closing
@@ -239,8 +238,8 @@ def __init__(self, enter_result: T = None):
     async def __aenter__(self) -> T:
         return self.enter_result
 
-    async def __aexit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> bool:
-        return False
+    async def __aexit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> None:
+        return None
 
 
 nullcontext = NullContext

asyncstdlib/contextlib.pyi

@@ -66,7 +66,7 @@ class closing(Generic[AClose]):
         exc_type: type[BaseException] | None,
         exc_val: BaseException | None,
         exc_tb: TracebackType | None,
-    ) -> bool: ...
+    ) -> None: ...
 
 class nullcontext(AsyncContextManager[T]):
     enter_result: T
@@ -84,7 +84,7 @@ class nullcontext(AsyncContextManager[T]):
         exc_type: type[BaseException] | None,
         exc_val: BaseException | None,
         exc_tb: TracebackType | None,
-    ) -> bool: ...
+    ) -> None: ...
 
 SE = TypeVar(
     "SE",

asyncstdlib/itertools.py

@@ -335,8 +335,8 @@ class NoLock:
     async def __aenter__(self) -> None:
         pass
 
-    async def __aexit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> bool:
-        return False
+    async def __aexit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> None:
+        return None
 
 
 async def tee_peer(
@@ -460,9 +460,8 @@ def __iter__(self) -> Iterator[AnyIterable[T]]:
     async def __aenter__(self) -> "Tee[T]":
         return self
 
-    async def __aexit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> bool:
+    async def __aexit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> None:
         await self.aclose()
-        return False
 
     async def aclose(self) -> None:
         for child in self._children:

asyncstdlib/itertools.pyi

@@ -132,7 +132,7 @@ class tee(Generic[T]):
     def __getitem__(self, item: slice) -> tuple[AsyncIterator[T], ...]: ...
     def __iter__(self) -> Iterator[AnyIterable[T]]: ...
     async def __aenter__(self: Self) -> Self: ...
-    async def __aexit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> bool: ...
+    async def __aexit__(self, exc_type: Any, exc_val: Any, exc_tb: Any) -> None: ...
     async def aclose(self) -> None: ...
 
 def pairwise(iterable: AnyIterable[T]) -> AsyncIterator[tuple[T, T]]: ...