CODEWITHSUNDEEP
javamockito
user860067
user860067

Reputation: 121

Mocking chained calls

The class under test is TestedClass which holds a field called "inner" from type InnerClass. 

Class TestedClass{

  InnerClass inner;

  public void methodToTest() {
     inner.getSomething().AddSomething(new Something());
  }
}

In my test i create a mock for "inner" and could not figure out how to test methodToTest, all option i've tried either do not compile and gets an exception from Mockito. What would be the proper way of mocking and testing this scenario?

Thanks.

Upvotes: 0

Views: 327

Answers (1)

Michal Lonski
Michal Lonski

Reputation: 887

You should inject InnerClass mock during TestedClass initialization. For example you should have a constructor:

class Something {
    void addSomething(Something sth) {
    }
}

class InnerClass {
    Something getSomething() {
        return new Something();
    }
}

class TestClass {

    private final InnerClass inner;

    TestClass(InnerClass inner) {
        this.inner = inner;
    }

    public void methodToTest() {
        inner.getSomething().addSomething(new Something());
    }
}

And the test verifying the call would be:

@Test
public void shouldInvokeInnerClassMethod() {
    InnerClass innerMock = Mockito.mock(InnerClass.class);
    TestClass testSubject = new TestClass(innerMock);

    testSubject.methodToTest();

    verify(innerMock).getSomething();
}

If you would like to test the value passed to addSometing method:

@Test
public void shouldAddSomething() {
    ArgumentCaptor<Something> somethingCaptor = ArgumentCaptor.forClass(Something.class);
    Something somethingMock = Mockito.mock(Something.class);
    InnerClass innerMock = Mockito.mock(InnerClass.class);
    when(innerMock.getSomething()).thenReturn(somethingMock);
    TestClass testSubject = new TestClass(innerMock);

    testSubject.methodToTest();

    verify(somethingMock).addSomething(somethingCaptor.capture());
    Something addedSomething = somethingCaptor.getValue();
    //assertions on addedSomething content
}

Upvotes: 2

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