Address PR review feedback

- Combine test_mypy_source and test_mypy_tests into single test_mypy function
- Remove unnecessary mypy config options and rely on defaults
- Remove native module ignores (not needed with TYPE_CHECKING guards)
- Add type annotations to all Camera.__init__ fields
- Use local variable pattern to ensure _backend is never None after init
- Use _closed flag instead of setting _backend to None in close()
- Remove assertions that checked for None backend
- Exclude test/win-dshow-capture from mypy checking
- Add return type annotation to get_pybind_include.__str__

Co-authored-by: letmaik <530988+letmaik@users.noreply.github.com>

Author: Copilot

mypy.ini

@@ -1,28 +1,8 @@
 [mypy]
-# Global options
+# Minimum Python version that the codebase should be compatible with
 python_version = 3.10
-warn_return_any = False
-warn_unused_configs = True
-disallow_untyped_defs = False
-check_untyped_defs = True
-# Allow implicit Optional (None defaults)
-no_implicit_optional = False
-
-# Ignore native extension modules that are built at install time
-[mypy-pyvirtualcam._native_windows_obs]
-ignore_missing_imports = True
-
-[mypy-pyvirtualcam._native_windows_unity_capture]
-ignore_missing_imports = True
-
-[mypy-pyvirtualcam._native_macos_obs_cmioextension]
-ignore_missing_imports = True
-
-[mypy-pyvirtualcam._native_macos_obs_dal]
-ignore_missing_imports = True
-
-[mypy-pyvirtualcam._native_linux_v4l2loopback]
-ignore_missing_imports = True
+# Exclude test helper modules with complex setup patterns
+exclude = test/win-dshow-capture/
 
 # Test-specific native modules
 [mypy-pyvirtualcam_win_dshow_capture.*]
@@ -34,3 +14,7 @@ ignore_missing_imports = True
 
 [mypy-imageio]
 ignore_missing_imports = True
+
+[mypy-pybind11]
+ignore_missing_imports = True
+

pyvirtualcam/camera.py

@@ -1,4 +1,4 @@
-from typing import Optional, Dict, Type, TYPE_CHECKING
+from typing import Optional, Dict, Type, TYPE_CHECKING, Callable
 from abc import ABC, abstractmethod
 import platform
 import time
@@ -210,28 +210,29 @@ def __init__(self, width: int, height: int, fps: float, *,
             backends = [(backend, BACKENDS[backend])]
         else:
             backends = list(BACKENDS.items())
-        self._backend = None
+        backend_instance: Optional[Backend] = None
         errors = []
         for name, clazz in backends:
             try:
-                self._backend = clazz(
+                backend_instance = clazz(
                     width=width, height=height, fps=fps,
                     fourcc=encode_fourcc(fmt.value),
                     device=device,
                     **kw)
             except Exception as e:
                 errors.append(f"'{name}' backend: {e}")
             else:
-                self._backend_name = name
+                self._backend_name: str = name
                 break
-        if self._backend is None:
+        if backend_instance is None:
             raise RuntimeError('\n'.join(errors))
-
-        self._width = width
-        self._height = height
-        self._fps = fps
-        self._fmt = fmt
-        self._print_fps = print_fps
+        
+        self._backend: Backend = backend_instance
+        self._width: int = width
+        self._height: int = height
+        self._fps: float = fps
+        self._fmt: PixelFormat = fmt
+        self._print_fps: bool = print_fps
 
         frame_shape = FrameShapes[fmt](width, height)
         if isinstance(frame_shape, int):
@@ -243,13 +244,14 @@ def check_frame_shape(frame: np.ndarray):
                 if frame.shape != frame_shape:
                     raise ValueError(f"unexpected frame shape: {frame.shape} != {frame_shape}")
 
-        self._check_frame_shape = check_frame_shape
+        self._check_frame_shape: Callable[[np.ndarray], None] = check_frame_shape
 
-        self._fps_counter = FPSCounter(fps)
-        self._fps_last_printed = time.perf_counter()
-        self._frames_sent = 0
-        self._last_frame_t = time.perf_counter()
-        self._extra_time_per_frame = 0.0
+        self._fps_counter: FPSCounter = FPSCounter(fps)
+        self._fps_last_printed: float = time.perf_counter()
+        self._frames_sent: int = 0
+        self._last_frame_t: float = time.perf_counter()
+        self._extra_time_per_frame: float = 0.0
+        self._closed: bool = False
 
     def __enter__(self):
         return self
@@ -270,7 +272,6 @@ def backend(self) -> str:
     def device(self) -> str:
         """ The virtual camera device in use.
         """
-        assert self._backend is not None
         return self._backend.device()
 
     @property
@@ -308,7 +309,6 @@ def native_fmt(self) -> Optional[PixelFormat]:
         For example, on Windows, a camera device typically
         supports multiple formats.
         """
-        assert self._backend is not None
         fourcc = self._backend.native_fourcc()
         return PixelFormat(decode_fourcc(fourcc)) if fourcc else None
 
@@ -324,9 +324,9 @@ def close(self) -> None:
         This method is automatically called when using ``with`` or
         when this instance goes out of scope.
         """
-        if self._backend is not None:
+        if not self._closed:
             self._backend.close()
-            self._backend = None
+            self._closed = True
 
     def send(self, frame: np.ndarray) -> None:
         """Send a frame to the virtual camera device.
@@ -356,7 +356,6 @@ def send(self, frame: np.ndarray) -> None:
             print(s)
 
         frame = np.asarray(frame.reshape(-1), order='C')
-        assert self._backend is not None
         self._backend.send(frame)
 
     @property

test/test_mypy.py

@@ -3,21 +3,11 @@
 import sys
 
 
-def test_mypy_source():
-    """Run mypy on the source folder."""
+def test_mypy():
+    """Run mypy on the source and test folders."""
     result = subprocess.run(
-        [sys.executable, '-m', 'mypy', '--install-types', '--non-interactive', 'pyvirtualcam'],
+        [sys.executable, '-m', 'mypy', '--install-types', '--non-interactive', 'pyvirtualcam', 'test'],
         capture_output=True,
         text=True
     )
-    assert result.returncode == 0, f"mypy failed on source folder:\n{result.stdout}\n{result.stderr}"
-
-
-def test_mypy_tests():
-    """Run mypy on the test folder."""
-    result = subprocess.run(
-        [sys.executable, '-m', 'mypy', '--install-types', '--non-interactive', 'test'],
-        capture_output=True,
-        text=True
-    )
-    assert result.returncode == 0, f"mypy failed on test folder:\n{result.stdout}\n{result.stderr}"
+    assert result.returncode == 0, f"mypy failed:\n{result.stdout}\n{result.stderr}"

test/win-dshow-capture/setup.py

@@ -12,7 +12,7 @@ class get_pybind_include(object):
     until it is actually installed, so that the ``get_include()``
     method can be invoked. """
 
-    def __str__(self):
+    def __str__(self) -> str:
         import pybind11
         return pybind11.get_include()