java and - Can Mockito capture arguments of a method called multiple times?




return argumentcaptor (5)

I think it should be

verify(mockBar, times(2)).doSomething(...)

Sample from mockito javadoc:

ArgumentCaptor<Person> peopleCaptor = ArgumentCaptor.forClass(Person.class);
verify(mock, times(2)).doSomething(peopleCaptor.capture());

List<Person> capturedPeople = peopleCaptor.getAllValues();
assertEquals("John", capturedPeople.get(0).getName());
assertEquals("Jane", capturedPeople.get(1).getName());

I have a method that gets called twice, and I want to capture the argument of the second method call.

Here's what I've tried:

ArgumentCaptor<Foo> firstFooCaptor = ArgumentCaptor.forClass(Foo.class);
ArgumentCaptor<Foo> secondFooCaptor = ArgumentCaptor.forClass(Foo.class);
verify(mockBar).doSomething(firstFooCaptor.capture());
verify(mockBar).doSomething(secondFooCaptor.capture());
// then do some assertions on secondFooCaptor.getValue()

But I get a TooManyActualInvocations Exception, as Mockito thinks that doSomething should only be called once.

How can I verify the argument of the second call of doSomething?


If you don't want to validate all the calls to doSomething(), only the last one, you can just use ArgumentCaptor.getValue(). According to the Mockito javadoc:

If the method was called multiple times then it returns the latest captured value

So this would work (assumes Foo has a method getName()):

ArgumentCaptor<Foo> fooCaptor = ArgumentCaptor.forClass(Foo.class);
verify(mockBar, times(2)).doSomething(fooCaptor.capture());
//getValue() contains value set in second call to doSomething()
assertEquals("2nd one", fooCaptor.getValue().getName());

You can also use @Captor annotated ArgumentCaptor. For example:

@Mock
List<String> mockedList;

@Captor
ArgumentCaptor<String> argCaptor;

@BeforeTest
public void init() {
    //Initialize objects annotated with @Mock, @Captor and @Spy.
    MockitoAnnotations.initMocks(this);
}

@Test
public void shouldCallAddMethodTwice() {
    mockedList.add("one");
    mockedList.add("two");
    Mockito.verify(mockedList, times(2)).add(argCaptor.capture());

    assertEquals("one", argCaptor.getAllValues().get(0));
    assertEquals("two", argCaptor.getAllValues().get(1));
}

With Java 8's lambdas, a convenient way is to use

org.mockito.invocation.InvocationOnMock

when(client.deleteByQuery(anyString(), anyString())).then(invocationOnMock -> {
    assertEquals("myCollection", invocationOnMock.getArgument(0));
    assertThat(invocationOnMock.getArgument(1), Matchers.startsWith("id:"));
}

As i needed to use this feature for my latest project (at one point we updated from 1.10.19), just to keep the users (that are already using the mockito-core version 2.1.0 or greater) up to date, the static methods from the above answers should be taken from ArgumentMatchers class:

import static org.mockito.ArgumentMatchers.isA;
import static org.mockito.ArgumentMatchers.any;

Please keep this in mind if you are planning to keep your mockito artifacts up to date as possibly starting from version 3, this class may no longer exist:

As per 2.1.0 and above, javadoc of org.mockito.Matchers states:

Use org.mockito.ArgumentMatchers. This class is now deprecated in order to avoid a name clash with Hamcrest * org.hamcrest.Matchers class. This class will likely be removed in version 3.0.





java unit-testing mocking mockito