Merge pull request #571 from testing-cabal/avoid-extensions

Avoid importing typing extensions unless type checking

Author: jelmer

pyproject.toml

@@ -39,6 +39,7 @@ twisted = ["Twisted", "fixtures"]
 dev = [
     "ruff==0.14.11",
     "mypy>=1.0.0",
+    "typing-extensions;python_version<'3.11'",
 ]
 
 [tool.hatch.version]

requirements.txt

@@ -1,2 +1 @@
 fixtures>=2.0
-typing-extensions;python_version<'3.11'

testtools/matchers/_higherorder.py

@@ -13,12 +13,13 @@
 import sys
 import types
 from collections.abc import Callable, Iterable
-from typing import Any, Generic, TypedDict, TypeVar
+from typing import TYPE_CHECKING, Any, Generic, TypedDict, TypeVar
 
-if sys.version_info >= (3, 11):
-    from typing import Unpack
-else:
-    from typing_extensions import Unpack
+if TYPE_CHECKING:
+    if sys.version_info >= (3, 11):
+        from typing import Unpack
+    else:
+        from typing_extensions import Unpack
 
 from ._impl import (
     Matcher,