mockito verify interactions with ArgumentCaptor

Question

To check the number of interactions with a mock where the parameter in the method call is of a certain type, one can do

mock.someMethod(new FirstClass()); mock.someMethod(new OtherClass()); verify(mock, times(1)).someMethod(isA(FirstClass.class)); 

This will pass thanks to the call to isA since someMethod was called twice but only once with argument FirstClass

However, this pattern seems to not be possible when using an ArgumentCaptor, even if the Captor was created for the particular argument FirstClass

this doesn't work

mock.someMethod(new FirstClass()); mock.someMethod(new OtherClass()); ArgumentCaptor<FirstClass> captor = ArgumentCaptor.forClass(FirstClass.class); verify(mock, times(1)).someMethod(captor.capture()); 

it says the mock was called more than once.

Is there any way to accomplish this verification while capturing the argument for further checking?

Answer 1

I recommend using Mockito's Hamcrest integration to write a good, clean matcher for it. That allows you to combine the verification with detailed checking of the passed argument:

import static org.mockito.hamcrest.MockitoHamcrest.argThat;  verify(mock, times(1)).someMethod(argThat(personNamed("Bob")));  Matcher<Person> personNamed(final String name) {     return new TypeSafeMatcher<Person>() {         public boolean matchesSafely(Person item) {             return name.equals(item.getName());         }         public void describeTo(Description description) {             description.appendText("a Person named " + name);         }     }; } 

Matchers generally lead to more readable tests and more useful test failure messages. They also tend to be very reusable, and you'll find yourself building up a library of them tailored for testing your project. Finally, you can also use them for normal test assertions using JUnit's Assert.assertThat(), so you get double use out of them.