I am trying to test a return from a method of my class in an Android project. I'm doing it this way:
MyClass var = Mockito.mock(MyClass.class);
With this, I already have my instance. Now I need to test methods of this class, I did it this way:
Mockito.doCallRealMethod().when(var).loadTexture("back.png")
The return is always coming null. But the image exists and was not meant to be returning null ...
The problem is that you are trying to test a "Mockada" class, that is, you are not testing the actual class but rather a "default" instance of it. That's why when you give loadTexture() it is returned null .
Mocks should be used to represent external objects and are required to execute methods of a class. For example:
public class MinhaClasseA{
private MinhaClasseB mcB;
public MinhaClasseA(MinhaClasseB mcB){
this.mcB = mcB
}
public int fazAlgumaCoisa(){
return mcB.fazOutraCoisa();
}
}
public class MinhaClasseB{
public int fazOutraCoisa(){
return 10;
}
}
In this case, we realize that class A has a dependence on class B, so if you wanted to test class A, you would have to create a class B mock and explain what values it returns, ie you I would say the behavior of class B and then you would check if class A acts correctly as it receives the data of B.
Example:
MinhaClasseB mcBMock = Mockito.mock(MinhaClasseB.class);
MinhaClasseA mcA = new MinhaClasseA(mcBMock);
int intMock = 10;
when(mcBMock.fazOutraCoisa()).thenReturn(intMock);
assertEquals(mcA.fazAlgumaCoisa(),intMock);
In this case, you are saying that when the fazOutraCoisa() method of B is called, it should return 10 to the caller (the class A). So when using assertEquals you want to know if class A is actually getting the return value of the fazOutraCoisa method of B.