Fix #6709: autodoc: mock object does not work as a class decorator

CHANGES

@@ -24,6 +24,7 @@ Bugs fixed
 
   .. _latex3/latex2e#173: https://github.com/latex3/latex2e/issues/173
 * #6618: LaTeX: Avoid section names at the end of a page
+* #6709: autodoc: mock object does not work as a class decorator
 
 Testing
 --------

sphinx/ext/autodoc/mock.py

@@ -60,7 +60,7 @@ class _MockObject:
         return _make_subclass(key, self.__display_name__, self.__class__)()
 
     def __call__(self, *args, **kw) -> Any:
-        if args and type(args[0]) in [FunctionType, MethodType]:
+        if args and type(args[0]) in [type, FunctionType, MethodType]:
             # Appears to be a decorator, pass through unchanged
             return args[0]
         return self

tests/test_ext_autodoc_mock.py

@@ -96,3 +96,24 @@ def test_abc_MockObject():
     assert isinstance(obj, Base)
     assert isinstance(obj, _MockObject)
     assert isinstance(obj.some_method(), Derived)
+
+
+def test_mock_decorator():
+    mock = _MockObject()
+
+    @mock.function_deco
+    def func():
+        """docstring"""
+
+    class Foo:
+        @mock.method_deco
+        def meth(self):
+            """docstring"""
+
+    @mock.class_deco
+    class Bar:
+        """docstring"""
+
+    assert func.__doc__ == "docstring"
+    assert Foo.meth.__doc__ == "docstring"
+    assert Bar.__doc__ == "docstring"