Add type assertions

resolves #17

Author: mikeshardmind

_misc/_type_assertions.py

@@ -0,0 +1,46 @@
+#   Copyright 2020-present Michael Hall
+#
+#   Licensed under the Apache License, Version 2.0 (the "License");
+#   you may not use this file except in compliance with the License.
+#   You may obtain a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#   Unless required by applicable law or agreed to in writing, software
+#   distributed under the License is distributed on an "AS IS" BASIS,
+#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#   See the License for the specific language governing permissions and
+#   limitations under the License.
+
+"""Type assertions for the more involed type transformations in the library."""
+
+from __future__ import annotations
+
+import asyncio
+from collections.abc import AsyncGenerator, Coroutine, Generator
+from typing import Any, assert_type
+
+from async_utils.corofunc_cache import lrucorocache
+from async_utils.gen_transform import sync_to_async_gen_noctx
+from async_utils.task_cache import lrutaskcache
+
+
+@lrutaskcache(ttl=60, maxsize=512)
+async def t1(a: int, b: str, *, x: bytes) -> str: ...
+
+
+assert_type(t1(1, "a", x=b""), asyncio.Task[str])
+
+
+@lrucorocache(ttl=60, maxsize=512)
+async def t2(a: int, b: str, *, x: bytes) -> str: ...
+
+
+_ = assert_type(t2(1, "a", x=b""), Coroutine[Any, Any, str])
+
+
+def gen() -> Generator[int]:
+    yield from range(10)
+
+
+_ = assert_type(sync_to_async_gen_noctx(gen), AsyncGenerator[int])

pyproject.toml

@@ -1,5 +1,5 @@
 [tool.pyright]
-include = ["src"]
+include = ["src", "_misc/_type_assertions.py"]
 exclude = [
     "**/__pycache__",
     "build",