Support typing via PyRight (#138)

* fix mixed named and anonymous arguments

* configure pyright

* reduce old-style types

* run pyright in CI

* use separate typetest

* document typing explicitly

.github/workflows/verification.yml

@@ -18,7 +18,7 @@ jobs:
     - name: Install dependencies
       run: |
         python -m pip install --upgrade pip
-        pip install .[test]
+        pip install .[test,typetest]
     - name: Lint with flake8
       run: |
         flake8 asyncstdlib unittests
@@ -28,3 +28,5 @@ jobs:
     - name: Verify with MyPy
       run: |
         mypy --pretty
+    - name: Verify with PyRight
+      uses: jakebailey/pyright-action@v2

asyncstdlib/_core.py

@@ -15,7 +15,6 @@
     AsyncGenerator,
     Iterable,
     AsyncIterable,
-    Union,
     Generic,
     Optional,
     Awaitable,
@@ -100,7 +99,7 @@ def borrow(iterator: AsyncIterator[T]) -> AsyncGenerator[T, None]:
 
 
 def awaitify(
-    function: Union[Callable[..., T], Callable[..., Awaitable[T]]]
+    function: "Callable[..., Awaitable[T]] | Callable[..., T]",
 ) -> Callable[..., Awaitable[T]]:
     """Ensure that ``function`` can be used in ``await`` expressions"""
     if iscoroutinefunction(function):
@@ -114,16 +113,16 @@ class Awaitify(Generic[T]):
 
     __slots__ = "__wrapped__", "_async_call"
 
-    def __init__(self, function: Union[Callable[..., T], Callable[..., Awaitable[T]]]):
+    def __init__(self, function: "Callable[..., Awaitable[T]] | Callable[..., T]"):
         self.__wrapped__ = function
-        self._async_call: Optional[Callable[..., Awaitable[T]]] = None
+        self._async_call: "Callable[..., Awaitable[T]] | None" = None
 
     def __call__(self, *args: Any, **kwargs: Any) -> Awaitable[T]:
         if (async_call := self._async_call) is None:
             value = self.__wrapped__(*args, **kwargs)
             if isinstance(value, Awaitable):
                 self._async_call = self.__wrapped__  # type: ignore
-                return value
+                return value  # pyright: ignore
             else:
                 self._async_call = force_async(self.__wrapped__)  # type: ignore
                 return await_value(value)

asyncstdlib/builtins.pyi

@@ -77,37 +77,43 @@ def zip(
 def map(
     function: Callable[[T1], Awaitable[R]],
     __it1: AnyIterable[T1],
+    /,
 ) -> AsyncIterator[R]: ...
 @overload
 def map(
     function: Callable[[T1], R],
     __it1: AnyIterable[T1],
+    /,
 ) -> AsyncIterator[R]: ...
 @overload
 def map(
     function: Callable[[T1, T2], Awaitable[R]],
     __it1: AnyIterable[T1],
     __it2: AnyIterable[T2],
+    /,
 ) -> AsyncIterator[R]: ...
 @overload
 def map(
     function: Callable[[T1, T2], R],
     __it1: AnyIterable[T1],
     __it2: AnyIterable[T2],
+    /,
 ) -> AsyncIterator[R]: ...
 @overload
 def map(
     function: Callable[[T1, T2, T3], Awaitable[R]],
     __it1: AnyIterable[T1],
     __it2: AnyIterable[T2],
     __it3: AnyIterable[T3],
+    /,
 ) -> AsyncIterator[R]: ...
 @overload
 def map(
     function: Callable[[T1, T2, T3], R],
     __it1: AnyIterable[T1],
     __it2: AnyIterable[T2],
     __it3: AnyIterable[T3],
+    /,
 ) -> AsyncIterator[R]: ...
 @overload
 def map(
@@ -116,6 +122,7 @@ def map(
     __it2: AnyIterable[T2],
     __it3: AnyIterable[T3],
     __it4: AnyIterable[T4],
+    /,
 ) -> AsyncIterator[R]: ...
 @overload
 def map(
@@ -124,6 +131,7 @@ def map(
     __it2: AnyIterable[T2],
     __it3: AnyIterable[T3],
     __it4: AnyIterable[T4],
+    /,
 ) -> AsyncIterator[R]: ...
 @overload
 def map(
@@ -133,6 +141,7 @@ def map(
     __it3: AnyIterable[T3],
     __it4: AnyIterable[T4],
     __it5: AnyIterable[T5],
+    /,
 ) -> AsyncIterator[R]: ...
 @overload
 def map(
@@ -142,6 +151,7 @@ def map(
     __it3: AnyIterable[T3],
     __it4: AnyIterable[T4],
     __it5: AnyIterable[T5],
+    /,
 ) -> AsyncIterator[R]: ...
 @overload
 def map(
@@ -151,6 +161,7 @@ def map(
     __it3: AnyIterable[Any],
     __it4: AnyIterable[Any],
     __it5: AnyIterable[Any],
+    /,
     *iterable: AnyIterable[Any],
 ) -> AsyncIterator[R]: ...
 @overload
@@ -161,6 +172,7 @@ def map(
     __it3: AnyIterable[Any],
     __it4: AnyIterable[Any],
     __it5: AnyIterable[Any],
+    /,
     *iterable: AnyIterable[Any],
 ) -> AsyncIterator[R]: ...
 @overload

asyncstdlib/heapq.py

@@ -2,8 +2,6 @@
 from typing import (
     Generic,
     AsyncIterator,
-    Tuple,
-    List,
     Optional,
     Callable,
     Any,
@@ -53,21 +51,21 @@ def __init__(
     @classmethod
     def from_iters(
         cls,
-        iterables: Tuple[AnyIterable[T], ...],
+        iterables: "tuple[AnyIterable[T], ...]",
         reverse: bool,
         key: Callable[[T], Awaitable[LT]],
     ) -> "AsyncIterator[_KeyIter[LT]]": ...
 
     @overload
     @classmethod
     def from_iters(
-        cls, iterables: Tuple[AnyIterable[LT], ...], reverse: bool, key: None
+        cls, iterables: "tuple[AnyIterable[LT], ...]", reverse: bool, key: None
     ) -> "AsyncIterator[_KeyIter[LT]]": ...
 
     @classmethod
     async def from_iters(
         cls,
-        iterables: Tuple[AnyIterable[Any], ...],
+        iterables: "tuple[AnyIterable[Any], ...]",
         reverse: bool,
         key: Optional[Callable[[Any], Any]],
     ) -> "AsyncIterator[_KeyIter[Any]]":
@@ -124,10 +122,10 @@ async def merge(
     """
     a_key = awaitify(key) if key is not None else None
     # sortable iterators with (reverse) position to ensure stable sort for ties
-    iter_heap: List[Tuple[_KeyIter[Any], int]] = [
+    iter_heap: "list[tuple[_KeyIter[Any], int]]" = [
         (itr, idx if not reverse else -idx)
         async for idx, itr in a_enumerate(
-            _KeyIter.from_iters(iterables, reverse, a_key)
+            _KeyIter[Any].from_iters(iterables, reverse, a_key)
         )
     ]
     try:
@@ -175,7 +173,7 @@ async def _largest(
     n: int,
     key: Callable[[T], Awaitable[LT]],
     reverse: bool,
-) -> List[T]:
+) -> "list[T]":
     ordered: Callable[[LT], LT] = ReverseLT if reverse else lambda x: x  # type: ignore
     async with ScopedIter(iterable) as iterator:
         # assign an ordering to items to solve ties
@@ -207,7 +205,7 @@ async def nlargest(
     iterable: AnyIterable[T],
     n: int,
     key: Optional[Callable[[Any], Awaitable[Any]]] = None,
-) -> List[T]:
+) -> "list[T]":
     """
     Return a sorted list of the ``n`` largest elements from the (async) iterable
 
@@ -229,7 +227,7 @@ async def nsmallest(
     iterable: AnyIterable[T],
     n: int,
     key: Optional[Callable[[Any], Awaitable[Any]]] = None,
-) -> List[T]:
+) -> "list[T]":
     """
     Return a sorted list of the ``n`` smallest elements from the (async) iterable
 

asyncstdlib/itertools.pyi

@@ -8,10 +8,9 @@ from typing import (
     Iterable,
     Callable,
     TypeVar,
-    Self,
     overload,
 )
-from typing_extensions import Literal
+from typing_extensions import Literal, Self
 
 from ._typing import AnyIterable, ADD, T, T1, T2, T3, T4, T5
 

docs/source/contributing.rst

@@ -8,13 +8,14 @@ where you can report bugs, request improvements or propose changes.
 
 - For bug reports and feature requests simply `open a new issue`_
   and fill in the appropriate template.
-- Even for content submissions it is highly recommended to make sure an issue
-  exists - this allows you to get early feedback and document the development.
+- Even for content submissions make sure `an issue exists`_ - this
+  allows you to get early feedback and document the development.
   You can use whatever tooling you like to create the content,
   but the next sections give a rough outline on how to proceed.
 
 .. _asyncstdlib GitHub repository: https://github.com/maxfischer2781/asyncstdlib
 .. _open a new issue: https://github.com/maxfischer2781/asyncstdlib/issues/new/choose
+.. _an issue exists: https://github.com/maxfischer2781/asyncstdlib/issues
 
 Submitting Content
 ==================
@@ -32,26 +33,34 @@ the extras ``test`` and ``doc``, respectively.
 .. note::
 
     Ideally you develop with the repository checked out locally and a separate `Python venv`_.
-    If you have the venv active and the current working directory is the repository root,
-    simply run `python -m pip install -e '.[test,doc]'` to install all dependencies.
+    If you have the venv active and are at the repository root,
+    run ``python -m pip install -e '.[test,typetest,doc]'`` to install all dependencies.
 
 .. _`GitHub Fork and Pull Request`: https://guides.github.com/activities/forking/
 .. _`Python venv`: https://docs.python.org/3/library/venv.html
 
 Testing Code
 ------------
 
-Code is verified locally using the tools `flake8`, `black`, `pytest` and `mypy`.
-If you do not have your own preferences we recommend the following order:
+Code can be verified locally using the tools `flake8`, `black`, `pytest`, `pyright` and `mypy`.
+You should always verify that the basic checks pass:
 
 .. code:: bash
 
     python -m black asyncstdlib unittests
     python -m flake8 asyncstdlib unittests
     python -m pytest
+
+This runs tests from simplest to most advanced and should allow a quick development cycle.
+
+In many cases you can rely on your IDE for type checking.
+For major typing related changes, run the full type checking:
+
+.. code:: bash
+
     python -m mypy --pretty
+    python -m pyright
 
-This runs tests from simplest to most advanced and should allow you quick development.
 Note that some additional checks are run on GitHub to check test coverage and code health.
 
 Building Docs

pyproject.toml

@@ -36,6 +36,10 @@ test = [
     "pytest-cov",
     "flake8-2020",
     "mypy; implementation_name=='cpython'",
+]
+typetest = [
+    "mypy; implementation_name=='cpython'",
+    "pyright",
     "typing-extensions",
 ]
 doc = ["sphinx", "sphinxcontrib-trio"]
@@ -64,6 +68,13 @@ warn_return_any = true
 no_implicit_reexport = true
 strict_equality = true
 
+[tool.pyright]
+include = ["asyncstdlib", "typetests"]
+typeCheckingMode = "strict"
+pythonPlatform = "All"
+pythonVersion = "3.8"
+verboseOutput = true
+
 [tool.pytest.ini_options]
 testpaths = [
     "unittests",