Java – mockito – I feel like I’m not making full use of its potential

When using mockito, I only use it to simulate dependencies, that is, my workflow looks like the following:

I have a dependent class:

public class C {
    public C (A a,B b) {
        this.a = a;
        this.b = b;
    }

    public String fooBar() {
        return a.foo() + b.bar();
    }
}

In my test class, I simulated these dependencies and told them what values to return when calling some specified methods:

public class CSpec {
    private A a = mock(A.class);
    private B b = mock(B.class);

    @Test
    public itShouldReturnFooBar() {
        when(a.foo()).thenReturn("foo");
        when(b.bar()).thenReturn("bar");

        C c = new C(a,b);

        assertThat(c.fooBar().isEqualTo("foobar"));
    }
}

(I hope this example is not too simple or too derivative; -) This works well and allows me to test classes separately (here: C) Nevertheless, I never use mockito's verification method or any other function Is it possible / sufficient to use mockito in this way?

Solution

Validation is usually used to check whether your C actually calls the A. foo () and B. bar () methods So you can add

verify(a).foo();
verify(b).foo();

Before or after an assertion I don't think you need or should use them here, but there are several situations where you need to:

> A or B executes common API invisible / accessible content of C, such as log records > you focus on execution order > you want to make sure you call A.Foo and b.bar only, instead of a.foo2, you can use those simulations as spies, then call A.Foo and then route to aReal.. foo