CODEWITHSUNDEEP
unit-testingmockito
Victor Grazi
Victor Grazi

Reputation: 16490

How can I verify that a method is called with a parameter that contains a certain value, without verifying the whole parameter?

I am testing a method that returns no results. The last step of the method is something like:

insertIntoDb(someObjectContainingAListField);

I could do 

verify(xx).insertIntoDb(eq(someObjectContainingAListField));

But that would verify the entire object contents; I only need to verify the list.

I really only want to verify that the List it contains is correct.

Is there any way to do so in Mockito?

Upvotes: 0

Views: 3486

Answers (1)

Jeff Bowman
Jeff Bowman

Reputation: 95644

You have two main choices: Use an ArgumentCaptor, or write an ArgumentMatcher.

ArgumentCaptor

ArgumentCaptor lets you get a reference to the object as part of your verification, so then you can make specific assertions about it. You can create them manually with ArgumentCaptor.forClass, or use the @Captor annotation with MockitoAnnotations or the Mockito Runner or Rule.

@Captor ArgumentCaptor<ListFieldContainer> listFieldContainerCaptor;

@Test public void yourTest() {
  yourClass.doSomething();
  verify(mockService).insertIntoDb(listFieldContainerCaptor.capture());
  ListFieldContainer listFieldContainer = listFieldContainerCaptor.getValue();
  assertEquals(3, listFieldContainer.getListField().size());
}

ArgumentMatcher (or Matcher)

Using a Mockito ArgumentMatcher or a Hamcrest Matcher, you can create an object that represents the predicate you're looking for.

@Test public void yourTest() {
  yourClass.doSomething();
  verify(mockService).insertIntoDb(argThat(
      new ArgumentMatcher<ListFieldContainer>() {
        @Override public boolean matches(ListFieldContainer container) {
          return (container.size() == 3);
        }
      });
}

Note that previous versions of Mockito relied directly on Hamcrest, such that Matchers.argThat took a Hamcrest matcher; newer versions of Mockito use ArgumentMatchers.argThat to take a Hamcrest-like ArgumentMatcher interface and MockitoHamcrest.argThat to adapt a proper Hamcrest matcher.

See also: Mockito - how to mock/verify a method call which accepts a new object?

Upvotes: 2

Related Questions