How to pass argument to return method in mockito

Question

I would like to pass argument of method I mock to return value

Example:

when(mockedObject.printEntries(anyLong()).thenReturn("%d entries");

Is there a way to achieve that?

Answer 1

You have to take advantage of the the thenAnswer feature:

Answer<String> answer = new Answer<String>() {
    public String answer(InvocationOnMock invocation) throws Throwable {
        Long long = invocation.getArgumentAt(0, Long.class);
        return long + " entries";
    }
};


when(mockedObject.printEntries(anyLong()).thenAnswer(answer);

Answer 2

For example:

    when(mockedObject.printEntries(anyLong()).thenAnswer(invocationOnMock -> {
        Long aLong = invocationOnMock.getArgumentAt(1, Long.class);
        return aLong + 2;
    });