At the excellent post Mocking is not rocket science are documented two alternatives:
returnsMany
specify a number of values that are used one by one i.e. first matched call returns first element, second returns second element:
every { mock1.call(5) } returnsMany listOf(1, 2, 3)
You can achieve the same using andThen construct:
every { mock1.call(5) } returns 1 andThen 2 andThen 3