Merge TypedDicts from typeshed

setuptools/command/easy_install.py

@@ -34,7 +34,7 @@
 from collections.abc import Iterable
 from glob import glob
 from sysconfig import get_path
-from typing import TYPE_CHECKING, Callable, NoReturn, TypeVar
+from typing import TYPE_CHECKING, Callable, NoReturn, TypedDict, TypeVar
 
 from jaraco.text import yield_lines
 
@@ -2039,14 +2039,19 @@ def chmod(path, mode):
         log.debug("chmod failed: %s", e)
 
 
+class _SplitArgs(TypedDict, total=False):
+    comments: bool
+    posix: bool
+
+
 class CommandSpec(list):
     """
     A command spec for a #! header, specified as a list of arguments akin to
     those passed to Popen.
     """
 
     options: list[str] = []
-    split_args: dict[str, bool] = dict()
+    split_args = _SplitArgs()
 
     @classmethod
     def best(cls):
@@ -2129,7 +2134,7 @@ def _render(items):
 
 
 class WindowsCommandSpec(CommandSpec):
-    split_args = dict(posix=False)
+    split_args = _SplitArgs(posix=False)
 
 
 class ScriptWriter:

setuptools/msvc.py

@@ -13,12 +13,15 @@
 import os
 import os.path
 import platform
-from typing import TYPE_CHECKING
+from typing import TYPE_CHECKING, TypedDict
 
 from more_itertools import unique_everseen
 
 import distutils.errors
 
+if TYPE_CHECKING:
+    from typing_extensions import NotRequired
+
 # https://github.com/python/mypy/issues/8166
 if not TYPE_CHECKING and platform.system() == 'Windows':
     import winreg
@@ -876,6 +879,14 @@ def _use_last_dir_name(path, prefix=''):
         return next(matching_dirs, None) or ''
 
 
+class _EnvironmentDict(TypedDict):
+    include: str
+    lib: str
+    libpath: str
+    path: str
+    py_vcruntime_redist: NotRequired[str | None]
+
+
 class EnvironmentInfo:
     """
     Return environment variables for specified Microsoft Visual C++ version
@@ -1420,7 +1431,7 @@ def VCRuntimeRedist(self) -> str | None:
         )
         return next(filter(os.path.isfile, candidate_paths), None)  # type: ignore[arg-type] #python/mypy#12682
 
-    def return_env(self, exists=True):
+    def return_env(self, exists: bool = True) -> _EnvironmentDict:
         """
         Return environment dict.
 
@@ -1434,7 +1445,7 @@ def return_env(self, exists=True):
         dict
             environment
         """
-        env = dict(
+        env = _EnvironmentDict(
             include=self._build_paths(
                 'include',
                 [