模拟子类对象和超类引用

Question

Here is the scenario, I have something like this in one of my method of cls:

public class xyz{
    public Object build(Map map) {

       BaseClass cls;

       if(SomeconditionTrue) {
         cls = new ChildClass1(new ABC());
       } else {
         cls = new ChildClass2(new ABC());
       }

       cls.callMethod();
    }
}

For the above scenario, I am writing a test case using PowerMockito, I want to mock this method call, cls.callMethod() . When i am trying the normal mocking, it calls the actual Method callMethod() that is failing. can some body please help me to mock that method call? Tried using couple of scenarios using PowerMockito.stub and some of other options, but its always calling the actual method.

Answer 1

Using Powermock you could do something like the following:

PowerMockito.whenNew(ChildClass1.class)
        .withArguments(any(ABC.class))
        .thenReturn(mockedBaseClass);

    PowerMockito.whenNew(ChildClass2.class)
        .withArguments(any(ABC.class))
        .thenReturn(mockedBaseClass);

Of course my preferred approach would be to pass in a factory that knows about how to make these ChildClass instances, then you could mock it using Mockito and it would be cleaner. However if that is not an option, hopefully the above should work.