Can Mockito verify parameters based on their values at the time of method call?

Answer 1

Use an Answer to check the value of the argument when the method is called. You can either throw an AssertionError within the Answer if the value is wrong, or you can store the value, and do your assertion at the end.

Answer 2

You can't call verify() on an object that is not a mock. Is this what you meant?

Bar collaborator = mock(Bar.class); 
Foo sut = spy(new Foo(collaborator));
verify(collaborator).run(expectedList);

Answer 3

Why don't you try using argument capture to acquire the value of expected list when it was run and then you can compare it.

ArgumentCaptor<List> listCaptor = ArgumentCaptor.forClass(List.class);

verify(collaborator).run(listCaptor.capture());

assertEquals(expectedList, argument.getValue());

Answer 4

The answer of Dawood ibn Kareem worked for me but I lacked an example, also I use Kotlin and Mockito-Kotlin, so my solution is like this:

class Foo(var mutable: String)

interface Bar {
    fun run(foo: Foo)
}

@Test fun `validate mutable parameter at invocation`() {
    val bar = mock<Bar>()

    var valueAtInvocation: String? = null
    whenever(bar.run(any())).then {
        val foo = it.arguments.first() as Foo
        valueAtInvocation = foo.mutable // Store mutable value as it was at the invocation
        Unit // The answer
    }

    val foo = Foo(mutable = "first")
    bar.run(foo)
    valueAtInvocation isEqualTo "first"

    foo.mutable = "second"
    bar.run(foo)
    valueAtInvocation isEqualTo "second"
}

valueAtInvocation will represent the value of the mutable property foo.mutable at the last invocation of bar.run(foo). Should also be possible to do assertions within the then {} block.