add test for class check

src/monty/json.py

@@ -105,16 +105,16 @@ class B(A):
     list all the types that an object can resolve to in order of generality
     (all objects have the builtins.object as the last one).
     """
+    # This function is intended as an alternative of "isinstance",
+    # therefore wouldn't check class
     if isclass(obj):
         return False
 
     type_str = type_str if isinstance(type_str, tuple) else (type_str,)
 
     mro = type(obj).mro()
 
-    return any(
-        o.__module__ + "." + o.__qualname__ == ts for o in mro for ts in type_str
-    )
+    return any(f"{o.__module__}.{o.__qualname__}" == ts for o in mro for ts in type_str)
 
 
 class MSONable:

tests/test_json.py

@@ -1096,6 +1096,26 @@ class B(A):
         assert _check_type(b, class_name_A)
         assert isinstance(b, A)
 
+    def test_check_type_with_class(self):
+        class A:
+            pass
+
+        class B(A):
+            pass
+
+        class_name_A = f"{A.__module__}.{A.__qualname__}"
+        class_name_B = f"{B.__module__}.{B.__qualname__}"
+
+        # Test class behavior (should return False, like isinstance does)
+        assert not _check_type(A, class_name_A)
+        assert not _check_type(B, class_name_B)
+        assert not _check_type(B, class_name_A)
+
+        # Ensure isinstance gives the same result (isinstance doesn't work with classes)
+        assert not isinstance(A, A)
+        assert not isinstance(B, B)
+        assert not isinstance(B, A)
+
     def test_callable(self):
         # Test function
         def my_function():