tests: Add test for when instance member overrides class member.

py/objtype.c

@@ -457,7 +457,7 @@ STATIC mp_obj_t instance_binary_op(mp_uint_t op, mp_obj_t lhs_in, mp_obj_t rhs_i
 }
 
 void mp_obj_instance_load_attr(mp_obj_t self_in, qstr attr, mp_obj_t *dest) {
-    // logic: look in obj members then class locals (TODO check this against CPython)
+    // logic: look in instance members then class locals
     assert(is_instance_type(mp_obj_get_type(self_in)));
     mp_obj_instance_t *self = self_in;
 

tests/basics/class_instance_override.py

@@ -0,0 +1,10 @@
+# test that we can override a class method with an instance method
+
+class A:
+    def foo(self):
+        return 1
+
+a = A()
+print(a.foo())
+a.foo = lambda:2
+print(a.foo())