Update typing.py

python · sharktide · Mar 5, 2025 · Mar 5, 2025 · Mar 5, 2025 · Mar 5, 2025
commit b38f68941c42f021172d489b8ee1b89300367ed3
@@ -475,6 +475,19 @@ def _eval_type(t, globalns, localns, type_params=_sentinel, *, recursive_guard=f
                t = t.__origin__[args]
            if is_unpacked:
                t = Unpack[t]
+            # Ensure the actual subclass is preserved
+            if ev_args == t.__args__:
+                return t
+            if isinstance(t, GenericAlias):
+                if _should_unflatten_callable_args(t, ev_args):
+                    return t.__class__(t.__origin__, (ev_args[:-1], ev_args[-1]))
+                return t.__class__(t.__origin__, ev_args)
+        if isinstance(t, Union):
+            return functools.reduce(operator.or_, ev_args)
+        else:
+            return t
+    return t
+

        ev_args = tuple(
            _eval_type(