Refactor + add tests to #569

Author: rmk135

src/dependency_injector/wiring.py

@@ -321,13 +321,7 @@ def _is_werkzeug_local_proxy(self, instance: object) -> bool:
     def _is_starlette_request_cls(self, instance: object) -> bool:
         return starlette \
                and isinstance(instance, type) \
-               and self._safe_is_subclass(instance, starlette.requests.Request)
-
-    def _safe_is_subclass(self, instance: type, cls: type) -> bool:
-        try:
-            return issubclass(instance, cls)
-        except TypeError:
-            return False
+               and _safe_is_subclass(instance, starlette.requests.Request)
 
     def _is_builtin(self, instance: object) -> bool:
         return inspect.isbuiltin(instance)
@@ -685,6 +679,13 @@ def _is_declarative_container(instance: Any) -> bool:
             and getattr(instance, "declarative_parent", None) is None)
 
 
+def _safe_is_subclass(instance: Any, cls: Type) -> bool:
+    try:
+        return issubclass(instance, cls)
+    except TypeError:
+        return False
+
+
 class Modifier:
 
     def modify(

tests/unit/samples/wiring/imports.py

@@ -5,7 +5,8 @@
 if "pypy" not in sys.version.lower():
     import numpy  # noqa
     from numpy import *  # noqa
-    from numpy.typing import *  # noqa
+    if sys.version_info >= (3, 7):
+        from numpy.typing import *  # noqa
 
     import scipy  # noqa
     from scipy import *  # noqa