如何在 java 中模拟 function 调用

Question

I am new to Unit testing and trying to figure out the different implementations of testing. I m trying to figure out how to mock a particular function call. I came across Mock Spy but didn't quite understand how it's been used. Can someone tell me how mocking is done in such cases...

Class ABC {
   
    void display(String name, int id){
       validateName(name);
       validateId(id);
     }
}


Class TestIt{
   
   @Test
   void testValidation(){

     //how to mock validateName function call and test only validateId ?
     ABC obj=new ABC();
     obj.display("abc",2);
   }
}

Answer 1

Some mocking frameworks allow partial mocks (most of the mocked class is actuall the real thing, just some methods are mocked). If your example is anywhere near the real code, I would not test the two methods separately. If one of these methods do something that is not wanted in a test, like accessing an external service (DB, webservice, filesystem), the I would encapsulate that functionality into an adapater class and inject it into ABC . Then you can mock the adapter.