chore: annotate types in some test helpers and fixtures

This didn't help with Pylint E1101, though; see
pylint-dev/pylint#9252

src/darker/tests/helpers.py

@@ -1,13 +1,19 @@
 """Helper functions for unit tests"""
 
+from __future__ import annotations
+
 import sys
 from contextlib import contextmanager
 from types import ModuleType
-from typing import Generator, Optional
+from typing import TYPE_CHECKING, Generator, Optional
 from unittest.mock import patch
 
 from darkgraylib.testtools.git_repo_plugin import GitRepoFixture
 
+if TYPE_CHECKING:
+    import pytest
+    from _pytest.fixtures import SubRequest
+
 
 @contextmanager
 def _package_present(
@@ -56,7 +62,9 @@ def flynt_present(present: bool) -> Generator[None, None, None]:
 
 
 @contextmanager
-def unix_and_windows_newline_repos(request, tmp_path_factory):
+def unix_and_windows_newline_repos(
+    request: SubRequest, tmp_path_factory: pytest.TempPathFactory
+) -> Generator[dict[str, GitRepoFixture], None, None]:
     """Create temporary repositories for Unix and windows newlines separately."""
     with GitRepoFixture.context(
         request, tmp_path_factory

src/darker/tests/test_git.py

@@ -8,9 +8,11 @@
 from subprocess import DEVNULL, check_call  # nosec
 from textwrap import dedent  # nosec
 from types import SimpleNamespace
+from typing import Generator
 from unittest.mock import ANY, patch
 
 import pytest
+from _pytest.fixtures import SubRequest
 
 from darker import git
 from darkgraylib.git import WORKTREE, RevisionRange
@@ -321,7 +323,9 @@ def test_git_get_modified_python_files(
 
 
 @pytest.fixture(scope="module")
-def git_get_modified_python_files_revision_range_repo(request, tmp_path_factory):
+def git_get_modified_python_files_revision_range_repo(
+    request: SubRequest, tmp_path_factory: pytest.TempPathFactory
+) -> Generator[GitRepoFixture]:
     """Fixture for a Git repository with multiple commits and branches."""
     yield from branched_repo(request, tmp_path_factory)