Enable mypy's strict equality checks

This would have caught an issue I had when writing
pypa#12204

setup.cfg

@@ -36,11 +36,14 @@ per-file-ignores =
 
 [mypy]
 mypy_path = $MYPY_CONFIG_FILE_DIR/src
+
+strict = True
+
+no_implicit_reexport = False
+allow_subclassing_any = True
+allow_untyped_calls = True
+warn_return_any = False
 ignore_missing_imports = True
-disallow_untyped_defs = True
-disallow_any_generics = True
-warn_unused_ignores = True
-no_implicit_optional = True
 
 [mypy-pip._internal.utils._jaraco_text]
 ignore_errors = True

src/pip/_internal/utils/temp_dir.py

@@ -196,7 +196,11 @@ def onerror(
  traceback.format_exception_only(type(exc_val), exc_val)
  )
  formatted_exc = formatted_exc.rstrip() # remove trailing new line
- if func in (os.unlink, os.remove, os.rmdir):
+ if func in (
+ os.unlink,
+ os.remove,
+ os.rmdir,
+ ): # type: ignore[comparison-overlap]
  logger.debug(
  "Failed to remove a temporary file '%s' due to %s.\n",
  path,

tests/functional/test_list.py

@@ -601,8 +601,7 @@ def test_outdated_formats(script: PipTestEnvironment, data: TestData) -> None:
  "--outdated",
  "--format=json",
  )
- data = json.loads(result.stdout)
- assert data == [
+ assert json.loads(result.stdout) == [
  {
  "name": "simple",
  "version": "1.0",

tests/lib/__init__.py

@@ -46,7 +46,9 @@
  # Literal was introduced in Python 3.8.
  from typing import Literal
 
- ResolverVariant = Literal["resolvelib", "legacy"]
+ ResolverVariant = Literal[
+ "resolvelib", "legacy", "2020-resolver", "legacy-resolver"
+ ]
 else:
  ResolverVariant = str
 

tests/unit/test_network_auth.py

@@ -352,7 +352,7 @@ def get_credential(self, system: str, username: str) -> Optional[Credential]:
  ),
 )
 def test_keyring_get_credential(
- monkeypatch: pytest.MonkeyPatch, url: str, expect: str
+ monkeypatch: pytest.MonkeyPatch, url: str, expect: Tuple[str, str]
 ) -> None:
  monkeypatch.setitem(sys.modules, "keyring", KeyringModuleV2())
  auth = MultiDomainBasicAuth(

tests/unit/test_options.py

@@ -2,7 +2,7 @@
 from contextlib import contextmanager
 from optparse import Values
 from tempfile import NamedTemporaryFile
-from typing import Any, Dict, Iterator, List, Tuple, Union, cast
+from typing import Any, Dict, Iterator, List, Tuple, Type, Union, cast
 
 import pytest
 
@@ -605,7 +605,7 @@ def test_config_file_options(
  self,
  monkeypatch: pytest.MonkeyPatch,
  args: List[str],
- expect: Union[None, str, PipError],
+ expect: Union[None, str, Type[PipError]],
  ) -> None:
  cmd = cast(ConfigurationCommand, create_command("config"))
  # Replace a handler with a no-op to avoid side effects

tests/unit/test_target_python.py

@@ -99,17 +99,17 @@ def test_get_sorted_tags(
  py_version_info: Optional[Tuple[int, ...]],
  expected_version: Optional[str],
  ) -> None:
- mock_get_supported.return_value = ["tag-1", "tag-2"]
+ dummy_tags = [Tag("py4", "none", "any"), Tag("py5", "none", "any")]
+ mock_get_supported.return_value = dummy_tags
 
  target_python = TargetPython(py_version_info=py_version_info)
  actual = target_python.get_sorted_tags()
- assert actual == ["tag-1", "tag-2"]
+ assert actual == dummy_tags
 
- actual = mock_get_supported.call_args[1]["version"]
- assert actual == expected_version
+ assert mock_get_supported.call_args[1]["version"] == expected_version
 
  # Check that the value was cached.
- assert target_python._valid_tags == ["tag-1", "tag-2"]
+ assert target_python._valid_tags == dummy_tags
 
  def test_get_unsorted_tags__uses_cached_value(self) -> None:
  """