Suggestion

I would like to suggest adding an API allowing for assertions during parameter verification without argument captors in simple cases.

Motivation

In my projects I generally use Mockito and AssertJ for testing. For non trivial method parameters, I often encounter the following ArgumentCaptor pattern:

ClassUnderTest classUnderTest = new ClassUnderTest(otherServiceMock);

classUnderTest.method();

ArgumentCaptor<Param> paramArgumentCaptor = ArgumentCaptor.forClass(Param.class);
verify(otherServiceMock).doStuff(paramArgumentCaptor.capture());
Param paramFromCaptor = paramArgumentCaptor.getValue();
assertThat(paramFromCaptor.getField1()).isEqualTo("value1");
assertThat(paramFromCaptor.getField2()).isEqualTo("value2");

This is fine, but a little bit verbose.

An alternative pattern I find myself using lately is using the argThat argument matcher to eliminate the captor, resulting in the verify statement looking something like this:

verify(otherServiceMock).doStuff(argThat(param -> {
    assertThat(param.getField1()).isEqualTo("value1");
    assertThat(param.getField2()).isEqualTo("value2");
    return true;
}));

In my opinion, at least in simple cases where only assertions on a single parameter are desired, this looks a little cleaner. Just the return statement is a bit pointless.

My suggestion is adding an API that would allow eliminating the return statement in this pattern, for example:

verify(otherServiceMock).doStuff(assertArg(param -> {
    assertThat(param.getField1()).isEqualTo("value1");
    assertThat(param.getField2()).isEqualTo("value2");
}));

Or is there already an API that would allow a similar pattern that I've missed?