mypy: disallow untyped defs by default (#11862)

Change our mypy configuration to disallow untyped defs by default, which ensures *new* files added to the code base are fully typed.

To avoid having to type-annotate everything now, add `# mypy: allow-untyped-defs` to files which are not fully type annotated yet.

As we fully type annotate those modules, we can then just remove that directive from the top.

Author: nicoddemus

setup.cfg

@@ -94,6 +94,7 @@ formats = sdist.tgz,bdist_wheel
 mypy_path = src
 check_untyped_defs = True
 disallow_any_generics = True
+disallow_untyped_defs = True
 ignore_missing_imports = True
 show_error_codes = True
 strict_equality = True

src/_pytest/_code/code.py

@@ -1,3 +1,4 @@
+# mypy: allow-untyped-defs
 import ast
 import dataclasses
 import inspect

src/_pytest/_code/source.py

@@ -1,3 +1,4 @@
+# mypy: allow-untyped-defs
 import ast
 import inspect
 import textwrap

src/_pytest/_io/pprint.py

@@ -1,3 +1,4 @@
+# mypy: allow-untyped-defs
 # This module was imported from the cpython standard library
 # (https://github.com/python/cpython/) at commit
 # c5140945c723ae6c4b7ee81ff720ac8ea4b52cfd (python3.12).

src/_pytest/_py/path.py

@@ -1,3 +1,4 @@
+# mypy: allow-untyped-defs
 """local path implementation."""
 from __future__ import annotations
 

src/_pytest/assertion/__init__.py

@@ -1,3 +1,4 @@
+# mypy: allow-untyped-defs
 """Support for presenting detailed information in failing assertions."""
 import sys
 from typing import Any

src/_pytest/assertion/util.py

@@ -1,3 +1,4 @@
+# mypy: allow-untyped-defs
 """Utilities for assertion debugging."""
 import collections.abc
 import os

src/_pytest/cacheprovider.py

@@ -1,3 +1,4 @@
+# mypy: allow-untyped-defs
 """Implementation of the cache provider."""
 # This plugin was not named "cache" to avoid conflicts with the external
 # pytest-cache version.

src/_pytest/capture.py

@@ -1,3 +1,4 @@
+# mypy: allow-untyped-defs
 """Per-test stdout/stderr capturing mechanism."""
 import abc
 import collections

src/_pytest/compat.py

@@ -1,3 +1,4 @@
+# mypy: allow-untyped-defs
 """Python version compatibility code."""
 from __future__ import annotations