Basic type-checking with mypy and pyright

.github/workflows/main.yml

@@ -97,12 +97,50 @@ jobs:
 
   # This job can be run locally with the `format_all.bat` script
   checkers:
-    runs-on: ubuntu-latest
+    runs-on: windows-2019
     steps:
       - uses: actions/checkout@v3
+      - uses: actions/setup-python@v4
+        with:
+          # This job only needs to target the oldest supported version (black@stable supports Python >=3.8)
+          python-version: '3.8'
       - run: pip install isort pycln
       - run: pycln . --config=pycln.toml --check
       - run: isort . --diff --check-only
       - uses: psf/black@stable
         with:
           options: "--fast --check --diff --verbose"
+
+  mypy:
+    runs-on: windows-2019
+    strategy:
+      fail-fast: false
+      matrix:
+        # 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: ${{ matrix.python-version }}
+      - run: pip install types-regex types-setuptools mypy>=1.5
+      - run: mypy . --python-version=${{ matrix.python-version }}
+
+  pyright:
+    runs-on: windows-2019
+    strategy:
+      fail-fast: false
+      matrix:
+        python-version: ['3.7', '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 }}
+      # pyright vendors typeshed, but let's make sure we have the most up to date stubs
+      - run: pip install types-regex types-setuptools
+      - uses: jakebailey/pyright-action@v2
+        with:
+          python-version: ${{ matrix.python-version }}
+          annotate: errors
+

Pythonwin/pywin/framework/stdin.py

@@ -168,4 +168,4 @@ def fake_input(prompt=None):
     finally:
         get_input_line = input
 else:
-    sys.stdin = Stdin()
+    sys.stdin = Stdin()  # type: ignore[assignment] # Not an actual TextIO

mypy.ini

@@ -0,0 +1,38 @@
+[mypy]
+show_column_numbers = true
+warn_unused_ignores = true
+; Target the oldest supported version in editors
+python_version = 3.7
+
+strict = false
+implicit_reexport = true
+
+; 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
+check_untyped_defs = false
+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)
+
+; C-modules that will need type-stubs
+[mypy-adsi.*,dde,exchange,exchdapi,perfmon,servicemanager,win32api,win32clipboard,win32event,win32evtlog,win32file,win32gui,win32help,win32pdh,win32process,win32ras,win32security,win32service,win32trace,win32ui,win32uiole,win32wnet,wincerapi,winxpgui,_win32sysloader,_winxptheme]
+ignore_missing_imports = True
+
+; verstamp is installed from win32verstamp.py called in setup.py
+; Most of win32com re-exports win32comext
+; Test is a local untyped module in win32comext.axdebug
+; pywin32_system32 is an empty module created in setup.py to store dlls
+[mypy-verstamp,win32com.*,Test,pywin32_system32]
+ignore_missing_imports = True

pyrightconfig.json

@@ -0,0 +1,60 @@
+{
+  "typeCheckingMode": "basic",
+  // Target the oldest supported version in editors
+  "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
+    "Pythonwin/pywin/idle/",
+    // Ignoring non-public apis for now
+    "**/Test/",
+    "**/test/",
+    "**/Demos/",
+    "**/demo/",
+  ],
+  // 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
+  "extraPaths": [
+    "com",
+    "win32/Lib",
+    "Pythonwin",
+  ],
+  // TODO: For now this allows us to at least put pyright in place by massively reducing checked code
+  // it also reduces issues with the shipped types-pywin32 from typeshed
+  "reportGeneralTypeIssues": "none",
+  "reportArgumentType": "none",
+  "reportAttributeAccessIssue": "none",
+  // FIXE: These all need to be fixed first and turned back to error
+  // some of the fixes need to be done in types-pywin32 from typeshed
+  "reportAssignmentType": "warning",
+  "reportCallIssue": "warning",
+  "reportIndexIssue": "warning",
+  "reportOperatorIssue": "warning",
+  "reportOptionalCall": "warning",
+  "reportOptionalIterable": "warning",
+  "reportOptionalMemberAccess": "warning",
+  "reportOptionalSubscript": "warning",
+  // TODO: Leave Unbound/Undefined to its own PR(s)
+  "reportUnboundVariable": "warning",
+  "reportUndefinedVariable": "warning",
+  // Too many dynamically generated modules. This will require type stubs to properly fix.
+  "reportMissingImports": "warning",
+  // IDEM, but happens when pywin32 is not in site-packages but module is found from typeshed.
+  // TODO: Is intended to be fixed with an editable install
+  // Since we're a library, and not user code, we care less about forgetting to install a dependency,
+  // as long as we have its stubs. So just disabling for now is fine.
+  "reportMissingModuleSource": "none",
+  // External type stubs may not be completable, and this will require type stubs for dynamic modules.
+  "reportMissingTypeStubs": "information",
+  // Sometimes used for extra runtime safety
+  "reportUnnecessaryComparison": "warning",
+  // Use Flake8/Pycln/Ruff instead
+  "reportUnusedImport": "none",
+}

pywin32_postinstall.py

@@ -2,19 +2,14 @@
 #
 # copies pywintypesXX.dll and pythoncomXX.dll into the system directory,
 # and creates a pth file
+import argparse
 import glob
 import os
 import shutil
 import sys
 import sysconfig
-
-try:
-    import winreg as winreg
-except:
-    import winreg
-
-# Send output somewhere so it can be found if necessary...
-import tempfile
+import tempfile  # Send output somewhere so it can be found if necessary...
+import winreg
 
 tee_f = open(os.path.join(tempfile.gettempdir(), "pywin32_postinstall.log"), "w")
 
@@ -44,11 +39,11 @@ def flush(self):
 # with sys.stdout as None but stderr is hooked up. This work-around allows
 # bdist_wininst to see the output we write and display it at the end of
 # the install.
-if sys.stdout is None:
+if sys.stdout is None:  # pyright: ignore[reportUnnecessaryComparison]
     sys.stdout = sys.stderr
 
-sys.stderr = Tee(sys.stderr)
-sys.stdout = Tee(sys.stdout)
+sys.stderr = Tee(sys.stderr)  # type: ignore[assignment] # Not an actual TextIO
+sys.stdout = Tee(sys.stdout)  # type: ignore[assignment] # Not an actual TextIO
 
 com_modules = [
     # module_name,                      class_names
@@ -193,7 +188,9 @@ 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(mod)
+    spec.loader.exec_module(  # pyright: ignore[reportOptionalMemberAccess] # We provide the loader, we know it won't be None
+        mod
+    )
 
 
 def SetPyKeyVal(key_name, value_name, value):
@@ -697,8 +694,6 @@ def verify_destination(location):
 
 
 def main():
-    import argparse
-
     parser = argparse.ArgumentParser(
         formatter_class=argparse.RawDescriptionHelpFormatter,
         description="""A post-install script for the pywin32 extensions.

win32/Lib/sspi.py

@@ -372,7 +372,7 @@ def authorize(self, sec_buffer_in):
     sec_buffer = None
     client_step = 0
     server_step = 0
-    while not (sspiclient.authenticated) or len(sec_buffer[0].Buffer):
+    while not sspiclient.authenticated or (sec_buffer and len(sec_buffer[0].Buffer)):
         client_step += 1
         err, sec_buffer = sspiclient.authorize(sec_buffer)
         print("Client step %s" % client_step)