Add pyright type-checking to tox configuration

Author: tjkuson

changelog.d/731.downstream.rst

@@ -0,0 +1 @@
+Added pyright type-checking.

pytest_asyncio/plugin.py

@@ -418,6 +418,7 @@ def _from_function(cls, function: Function, /) -> Function:
         Function item.
         """
         assert function.get_closest_marker("asyncio")
+        assert function.parent is not None
         subclass_instance = cls.from_parent(
             function.parent,
             name=function.name,

tox.ini

@@ -1,6 +1,6 @@
 [tox]
 minversion = 4.9.0
-envlist = py39, py310, py311, py312, py313, py314, pytest-min, docs
+envlist = py39, py310, py311, py312, py313, py314, pytest-min, docs, pyright
 isolated_build = true
 passenv =
     CI
@@ -69,6 +69,13 @@ passenv =
     SSH_AUTH_SOCK
 skip_install = false
 
+[testenv:pyright]
+deps =
+    pyright[nodejs]
+    pytest
+commands = pyright pytest_asyncio/
+skip_install = true
+
 [gh-actions]
 python =
     3.9: py39, pytest-min