Several typecheck improvements related to mypy 0.941.

This changes the way we test for specific platforms according to what mypy
understands and it runs mypy in CI against all platforms (linux/win32/darwin).

Author: jonathanslenders

.github/workflows/test.yaml

@@ -32,7 +32,9 @@ jobs:
         # Check wheather the imports were sorted correctly.
         # When this fails, please run ./tools/sort-imports.sh
         run: |
-          mypy --strict prompt_toolkit
+          mypy --strict prompt_toolkit --platform win32
+          mypy --strict prompt_toolkit --platform linux
+          mypy --strict prompt_toolkit --platform darwin
           isort -c --profile black prompt_toolkit examples tests setup.py
           black --check prompt_toolkit examples tests setup.py
       - name: Validate README.md

mypy.ini

@@ -1,6 +1,4 @@
 [mypy]
-platform = win32
-
 # --strict.
 check_untyped_defs = True
 disallow_any_generics = True

prompt_toolkit/application/application.py

@@ -89,7 +89,6 @@
 )
 from prompt_toolkit.utils import Event, in_main_thread
 
-from ..utils import is_windows
 from .current import get_app_session, set_app
 from .run_in_terminal import in_terminal, run_in_terminal
 
@@ -663,7 +662,7 @@ async def run_async(
         """
         assert not self._is_running, "Application is already running."
 
-        if not in_main_thread() or is_windows():
+        if not in_main_thread() or sys.platform == "win32":
             # Handling signals in other threads is not supported.
             # Also on Windows, `add_signal_handler(signal.SIGINT, ...)` raises
             # `NotImplementedError`.

prompt_toolkit/eventloop/inputhook.py

@@ -26,13 +26,12 @@
 import os
 import select
 import selectors
+import sys
 import threading
 from asyncio import AbstractEventLoop
 from selectors import BaseSelector, SelectorKey
 from typing import TYPE_CHECKING, Any, Callable, List, Mapping, Optional, Tuple
 
-from prompt_toolkit.utils import is_windows
-
 from .utils import get_event_loop
 
 __all__ = [
@@ -141,7 +140,7 @@ def input_is_ready() -> bool:
             #       However, if we would ever want to add a select call, it
             #       should use `windll.kernel32.WaitForMultipleObjects`,
             #       because `select.select` can't wait for a pipe on Windows.
-            if not is_windows():
+            if sys.platform != "win32":
                 select.select([self._r], [], [], None)
 
             os.read(self._r, 1024)

prompt_toolkit/eventloop/win32.py

@@ -1,3 +1,7 @@
+import sys
+
+assert sys.platform == "win32"
+
 from ctypes import pointer
 
 from ..utils import SPHINX_AUTODOC_RUNNING

prompt_toolkit/input/defaults.py

@@ -1,8 +1,6 @@
 import sys
 from typing import ContextManager, Optional, TextIO
 
-from prompt_toolkit.utils import is_windows
-
 from .base import DummyInput, Input, PipeInput
 
 __all__ = [
@@ -23,7 +21,7 @@ def create_input(
         `sys.stdin`. (We can open `stdout` or `stderr` for reading, this is how
         a `$PAGER` works.)
     """
-    if is_windows():
+    if sys.platform == "win32":
         from .win32 import Win32Input
 
         # If `stdin` was assigned `None` (which happens with pythonw.exe), use
@@ -61,7 +59,7 @@ def create_pipe_input() -> ContextManager[PipeInput]:
     Breaking change: In prompt_toolkit 3.0.28 and earlier, this was returning
     the `PipeInput` directly, rather than through a context manager.
     """
-    if is_windows():
+    if sys.platform == "win32":
         from .win32_pipe import Win32PipeInput
 
         return Win32PipeInput.create()

prompt_toolkit/input/posix_pipe.py

@@ -1,3 +1,7 @@
+import sys
+
+assert sys.platform != "win32"
+
 import os
 from contextlib import contextmanager
 from typing import ContextManager, Iterator, TextIO, cast

prompt_toolkit/input/vt100.py

@@ -1,6 +1,9 @@
+import sys
+
+assert sys.platform != "win32"
+
 import contextlib
 import io
-import sys
 import termios
 import tty
 from asyncio import AbstractEventLoop

prompt_toolkit/input/win32.py

@@ -7,6 +7,8 @@
 
 from ..utils import SPHINX_AUTODOC_RUNNING
 
+assert sys.platform == "win32"
+
 # Do not import win32-specific stuff when generating documentation.
 # Otherwise RTD would be unable to generate docs for this module.
 if not SPHINX_AUTODOC_RUNNING:

prompt_toolkit/input/win32_pipe.py

@@ -1,3 +1,7 @@
+import sys
+
+assert sys.platform == "win32"
+
 from contextlib import contextmanager
 from ctypes import windll
 from ctypes.wintypes import HANDLE