如何使用 JMockit 中的给定构造函数对模拟类的特定实例进行验证？

Question

I've been using JMockit to mock dependencies for a robot (such as sensors, joysticks, etc). For one of my classes' tests, I need to mock two joystick objects.

In the code I have, the Joysticks are instantiated as so:

Joystick joystick1 = new Joystick(0);
Joystick joystick2 = new Joystick(1);

I've been reading up on how to match specific instances of objects in theInstance matching section in the JMockit documentation .

These steps however don't seem to work for verifications (or maybe I'm doing it wrong) or they involve using the @Mocked tag in the parameters of every test method which would be a hassle given the fact that I want this behaviour to carry for an entire class of several tests.

I cannot simply inject the mocked instances into the tested class since the tested class actually receives them from another class in the application, and I'd rather not mock my own codebase in order to pass in the injectable joysticks.

The behaviour that I'm aiming for is something like this:

public class ClassUsingJoysticksTest {
    @Injectable
    private Joystick joystick1;

    @Injectable
    private Joystick joystick2;

    @Before
    public void setUp() {
        new Expectations() {{
            new Joystick(0);
            result = joystick1;

            new Joystick(1);
            result = joystick2;
        }};
    }

    @Test
    public void someTest() {
        ClassThatUsesJoysticks classThatUsesJoysticks = new ClassThatUsesJoysticks();
        classThatUsesJoysticks.doSomething();

        new Verifications() {{
            joystick1.setRumble(1D);
            joystick2.setRumble(2D);
        }};
    }
}

Relevant portion of the class under test:

public class ClassThatUsesJoysticks {
    public void doSomething() {
        Joystick joystick1 = OI.getInstance().getJoystick1(); // OI is our own class.
        Joystick joystick2 = OI.getInstance().getJoystick2();

        joystick1.setRumble(1);
        joystick2.setRumble(2);
    }
}

// OI class that we used to keep track of operator interface.
public class OI {
    private Joystick joystick1, joystick2;

    public OI() {
        joystick1 = new Joystick(0); // First joystick is always on port 0.
        joystick2 = new Joystick(1); // Next joystick is port 1.
    }

    public Joystick getJoystick1() {
        return joystick1;
    }

    public Joystick getJoystick2() {
        return joystick2;
    }
}

Is something like this possible using JMockit?

If you like, the actual implementation that I'm trying to achieve (with the bad mocking of my own codebase) can be found here .

Answer 1

I have this working with the current setup, as documented .

public class ClassUsingJoysticksTest {
    @Mocked Joystick joystick1;
    @Mocked Joystick joystick2;

    @Before
    public void setUp() {
        new Expectations() {
            new Joystick(0);
            result = joystick1;

            new Joystick(1);
            result = joystick2;
        }
    }

    @Test
    public void testRumbles() {
        classThatUsesJoysticks.doSomething();

        new Verifications() {{
             joystick1.setRumble(1.0);
             joystick2.setRumble(1.0);
        }};
    }
}

If you would like to see the actual implementation, code is here .