Turn on strict typing in mypy (#2211)

.editorconfig

@@ -15,5 +15,5 @@ max_line_length = 88 # Same as Black
 [*.md]
 trim_trailing_whitespace = false
 
-[*.{yaml,yml,toml}]
+[*.{yaml,yml,json,toml}]
 indent_size = 2

.github/workflows/main.yml

@@ -116,14 +116,14 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        # mypy 1.5 dropped support for python 3.7
+        # mypy 1.5 dropped support for Python 3.7
         python-version: ['3.8', '3.9', '3.10', '3.11', '3.12']
     steps:
       - uses: actions/checkout@v3
       - uses: actions/setup-python@v4
         with:
           python-version: ${{ matrix.python-version }}
-      - run: pip install types-regex types-setuptools mypy>=1.5
+      - run: pip install types-regex types-setuptools mypy==1.9
       - run: mypy . --python-version=${{ matrix.python-version }}
 
   pyright:

com/win32com/__init__.py

@@ -9,7 +9,7 @@
 import win32api
 
 # flag if we are in a "frozen" build.
-_frozen = getattr(sys, "frozen", 1 == 0)
+_frozen = getattr(sys, "frozen", False)
 # pythoncom dumbly defaults this to zero - we believe sys.frozen over it.
 if _frozen and not getattr(pythoncom, "frozen", 0):
     pythoncom.frozen = sys.frozen

mypy.ini

@@ -1,33 +1,53 @@
 [mypy]
 show_column_numbers = true
-warn_unused_ignores = true
-; Target the oldest supported version in editors
-python_version = 3.7
+; Target the oldest supported version in editors and default CLI
+; mypy 1.5 dropped support for Python 3.7
+python_version = 3.8
 
-strict = false
+strict = true
 implicit_reexport = true
+; Necessary to avoid "same module name" issues
+explicit_package_bases = true
+; Must specify top-level packages and scripts folders for mypy to work with explicit_package_bases
+mypy_path =
+    $MYPY_CONFIG_FILE_DIR/com,
+    $MYPY_CONFIG_FILE_DIR/win32/Lib,
+    $MYPY_CONFIG_FILE_DIR/Pythonwin,
+    $MYPY_CONFIG_FILE_DIR/AutoDuck,
+    $MYPY_CONFIG_FILE_DIR/win32/scripts/VersionStamp,
 
-; Implicit return types !
-; TODO: turn back check_untyped_defs to true. For now this allows us to
-; at least put mypy in place by massively reducing checked code
+; TODO: Gradually type classes and functions until we can turn back check_untyped_defs to true.
+; For now this allows us to at least put mypy in place by massively reducing checked code
 check_untyped_defs = false
+; Implicit return types !
 disallow_untyped_calls = false
 disallow_untyped_defs = false
 disallow_incomplete_defs = false
 
-; attr-defined: Module has no attribute (modules are dynamic)
-; method-assign: Cannot assign to a method (lots of monkey patching)
-; name-defined: Name "..." is not defined (dynamic modules will be hard to type without stubs, ie: pythoncom.*, leave undefined/unbound to Flake8/Ruff/pyright)
-disable_error_code = attr-defined, method-assign, name-defined
-; TODO: adodbapi should be updated and fixed separatly
-; Pythonwin/Scintilla is vendored
-; Pythonwin/pywin/idle is vendored IDLE extensions predating Python 2.3. They now live in idlelib in https://github.com/python/cpython/tree/main/Lib/idlelib
-; Ignoring non-public apis for now
-; Duplicate module named "rasutil" and "setup", short-term fix is to ignore
-exclude = .*((build|adodbapi|Pythonwin/Scintilla|Pythonwin/pywin/idle|[Tt]est|[Dd]emos?)/.*|rasutil.py|setup.py)
+disable_error_code =
+    ; Module has no attribute; (Dynamic modules will be hard to type without first-party stubs, ie: pythoncom.*)
+    attr-defined,
+    ; Class cannot subclass "..." (has type "Any"); (IDEM)
+    ; TODO: Use typeshed's types-pywin32 stubs after a few more fixes there
+    misc,
+    ; Name "..." is not defined; (IDEM, leave undefined/unbound to Flake8/Ruff/pyright)
+    name-defined,
+    ; Cannot assign to a method (we do lots of monkey patching)
+    method-assign,
+exclude = (?x)(
+    ^build/
+    ; Vendored
+    | ^Pythonwin/Scintilla/
+    ; Forked IDLE extensions predating Python 2.3. They now live in idlelib in https://github.com/python/cpython/tree/main/Lib/idlelib
+    | ^Pythonwin/pywin/idle/
+    ; TODO: adodbapi should be updated and fixed separatly
+    | ^adodbapi/
+    ; TODO: Ignoring non-public APIs until all public API is typed
+    | ([Tt]est|[Dd]emos?)/
+    )
 
 ; C-modules that will need type-stubs
-[mypy-adsi.*,dde,exchange,exchdapi,perfmon,servicemanager,win32api,win32console,win32clipboard,win32event,win32evtlog,win32file,win32gui,win32help,win32pdh,win32process,win32ras,win32security,win32service,win32trace,win32ui,win32uiole,win32wnet,_win32sysloader,_winxptheme]
+[mypy-adsi.*,dde,exchange,exchdapi,mapi,perfmon,servicemanager,win32api,win32console,win32clipboard,win32comext.adsi.adsi,win32event,win32evtlog,win32file,win32gui,win32help,win32pdh,win32process,win32ras,win32security,win32service,win32trace,win32ui,win32uiole,win32wnet,_win32sysloader,_winxptheme]
 ignore_missing_imports = True
 
 ; verstamp is installed from win32verstamp.py called in setup.py
@@ -36,3 +56,8 @@ ignore_missing_imports = True
 ; pywin32_system32 is an empty module created in setup.py to store dlls
 [mypy-verstamp,win32com.*,Test,pywin32_system32]
 ignore_missing_imports = True
+
+; Distutils being removed from stdlib currently causes some issues on Python 3.12
+; https://github.com/mhammond/pywin32/issues/2119
+[mypy-distutils.*]
+ignore_missing_imports = True

pyrightconfig.json

@@ -1,23 +1,23 @@
 {
   "typeCheckingMode": "basic",
-  // Target the oldest supported version in editors
+  // Target the oldest supported version in editors and default CLI
   "pythonVersion": "3.7",
   // Keep it simple for now by allowing both mypy and pyright to use `type: ignore`
   "enableTypeIgnoreComments": true,
   // Exclude from scanning when running pyright
   "exclude": [
     "build/",
-    // TODO: adodbapi should be updated and fixed separatly
-    "adodbapi/",
     // Vendored
     "Pythonwin/Scintilla/",
-    // Vendored IDLE extensions predating Python 2.3. They now live in idlelib in https://github.com/python/cpython/tree/main/Lib/idlelib
+    // Forked IDLE extensions predating Python 2.3. They now live in idlelib in https://github.com/python/cpython/tree/main/Lib/idlelib
     "Pythonwin/pywin/idle/",
     // Ignoring non-public apis for now
     "**/Test/",
     "**/test/",
     "**/Demos/",
     "**/demo/",
+    // TODO: adodbapi should be updated and fixed separately
+    "adodbapi/",
   ],
   // Packages that will be accessible globally.
   // Setting this makes pyright use the repo's code for those modules instead of typeshed or pywin32 in site-packages

pywin32_postinstall.py

@@ -188,9 +188,7 @@ def LoadSystemModule(lib_dir, modname):
     loader = importlib.machinery.ExtensionFileLoader(modname, filename)
     spec = importlib.machinery.ModuleSpec(name=modname, loader=loader, origin=filename)
     mod = importlib.util.module_from_spec(spec)
-    spec.loader.exec_module(  # pyright: ignore[reportOptionalMemberAccess] # We provide the loader, we know it won't be None
-        mod
-    )
+    loader.exec_module(mod)
 
 
 def SetPyKeyVal(key_name, value_name, value):

setup.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 build_id = "306"  # may optionally include a ".{patchno}" suffix.
 
 __doc__ = """This is a distutils setup-script for the pywin32 extensions.
@@ -44,6 +46,8 @@
 from setuptools.command.install import install
 from setuptools.command.install_lib import install_lib
 
+from distutils import ccompiler
+from distutils._msvccompiler import MSVCCompiler
 from distutils.command.install_data import install_data
 
 if sys.version_info >= (3, 8):
@@ -936,22 +940,17 @@ def my_new_compiler(**kw):
 
 
 # No way to cleanly wedge our compiler sub-class in.
-from distutils import ccompiler
-from distutils._msvccompiler import MSVCCompiler
-
 orig_new_compiler = ccompiler.new_compiler
-ccompiler.new_compiler = my_new_compiler
-
-base_compiler = MSVCCompiler
+ccompiler.new_compiler = my_new_compiler  # type: ignore[assignment] # Assuming the caller will always use only kwargs
 
 
-class my_compiler(base_compiler):
+class my_compiler(MSVCCompiler):
     # Just one GUIDS.CPP and it gives trouble on mainwin too. Maybe I
     # should just rename the file, but a case-only rename is likely to be
     # worse!  This can probably go away once we kill the VS project files
     # though, as we can just specify the lowercase name in the module def.
-    _cpp_extensions = base_compiler._cpp_extensions + [".CPP"]
-    src_extensions = base_compiler.src_extensions + [".CPP"]
+    _cpp_extensions = MSVCCompiler._cpp_extensions + [".CPP"]
+    src_extensions = MSVCCompiler.src_extensions + [".CPP"]
 
     def link(
         self,
@@ -1112,7 +1111,7 @@ def finalize_options(self):
     pch_header="PyWinTypes.h",
 )
 
-win32_extensions = [pywintypes]
+win32_extensions: list[WinExt] = [pywintypes]
 
 win32_extensions.append(
     WinExt_win32(
@@ -1254,11 +1253,10 @@ def finalize_options(self):
         windows_h_ver = info[2]
     if len(info) > 3:
         sources = info[3].split()
-    extra_compile_args = []
     ext = WinExt_win32(
         name,
         libraries=lib_names,
-        extra_compile_args=extra_compile_args,
+        extra_compile_args=[],
         windows_h_version=windows_h_ver,
         sources=sources,
     )
@@ -1425,8 +1423,8 @@ def finalize_options(self):
     base_address=dll_base_address,
 )
 dll_base_address += 0x80000  # pythoncom is large!
-com_extensions = [pythoncom]
-com_extensions += [
+com_extensions = [
+    pythoncom,
     WinExt_win32com(
         "adsi",
         libraries="ACTIVEDS ADSIID user32 advapi32",
@@ -2089,7 +2087,7 @@ def finalize_options(self):
 swig_include_files = "mapilib adsilib".split()
 
 
-def expand_modules(module_dir: Union[str, os.PathLike]):
+def expand_modules(module_dir: Union[str, os.PathLike[str]]):
     """Helper to allow our script specifications to include wildcards."""
     return [str(path.with_suffix("")) for path in Path(module_dir).rglob("*.py")]
 
@@ -2104,7 +2102,7 @@ def convert_data_files(files: Iterable[str]):
     for file in files:
         file = os.path.normpath(file)
         if file.find("*") >= 0:
-            files_use = (
+            files_use = tuple(
                 str(path)
                 for path in Path(file).parent.rglob(os.path.basename(file))
                 # We never want CVS

win32/Lib/win32timezone.py

@@ -1,4 +1,5 @@
 # -*- coding: UTF-8 -*-
+from __future__ import annotations
 
 """
 win32timezone:
@@ -231,7 +232,6 @@
 datetime.datetime(2011, 11, 6, 1, 0, tzinfo=TimeZoneInfo('Pacific Standard Time'))
 
 """
-from __future__ import annotations
 
 import datetime
 import logging
@@ -240,6 +240,7 @@
 import struct
 import winreg
 from itertools import count
+from typing import Dict
 
 import win32api
 
@@ -792,8 +793,8 @@ def get_sorted_time_zones(key=None):
         return zones
 
 
-class _RegKeyDict(dict):
-    def __init__(self, key):
+class _RegKeyDict(Dict[str, int]):
+    def __init__(self, key: winreg.HKEYType):
         dict.__init__(self)
         self.key = key
         self.__load_values()
@@ -907,7 +908,8 @@ def resolveMUITimeZone(spec):
 
 
 # from jaraco.util.dictlib 5.3.1
-class RangeMap(dict):
+# TODO: Update to implementation in jaraco.collections
+class RangeMap(dict):  # type: ignore[type-arg] # Source code is untyped :/ TODO: Add generics!
     """
     A dictionary-like object that uses the keys as bounds for a range.
     Inclusion of the value for that range is determined by the