Add tests

Author: qunaibit

graalpython/com.oracle.graal.python.test/src/tests/cpyext/test_object.py

@@ -305,6 +305,9 @@ def test_inheret_numbers_slots(self):
         assert X.B_has_add_slot()
         assert Y.E_has_add_slot()
 
+        # check dir & __dir__
+        assert sorted(list(B.__dir__())) == dir(B)
+
     def test_managed_class_with_native_base(self):
         NativeModule = CPyExtType("NativeModule_", 
                             '''

graalpython/com.oracle.graal.python.test/src/tests/test_object.py

@@ -104,6 +104,8 @@ def __init__(self):
     assert "d" in m.__dict__
     assert m.__dict__ == {'a': 10, 'd': 20}
 
+    # check dir & __dir__
+    assert sorted(list(m.__dir__())) == dir(m)
 
 def test_set_attr_builtins():
     lst = list()