ContactsTests.kt

@Test
fun `fetch contacts, api error`(){
  //given
  val errorMessage = "Bad request"
  whenver(api.fetchContacts()).thenReturn{Single.error(IllegalArgumentException(errorMessage)}
  //when
  presenter.fetchContacts()
  //then
  val inOrder = inOrder(view, api)
  inOrder.verify(view).showProgress()
  inOrder.verify(api).fetchContacts()
  inOrder.verify(view).hideProgress()
  inOrder.verify(view).showError(anyList)
  inOrder.verifyNoMoreInteractions()
}