CustomerRepoTest.kt

@Mock
private lateinit var endPoint: CustomerEndPoint

private lateinit var repo: CustomerRepoImpl
@Test
fun `should return customer data`() {
    val expectedCustomerResponse = mock(CustomerDetailResponse::class.java)
    `when`(endPoint.getCustomerData()).thenReturn(Single.create { it.onSuccess(Response.success(expectedCustomerResponse)) })
    val expectedCustomerDetail = mock(CustomerDetail::class.java)
    `when`(expectedexpectedCustomerResponse.data).thenReturn(expectedCustomerDetail)
    repo.fetchCustomerDetail().test()
            .assertComplete()
            .assertNoErrors()
            .assertValue {
                Assert.assertEquals(expectedCustomerDetail, it)
                true
            }

    verify(endPoint).getCustomerDetail()
}
@Test
fun `should return error for customer detail`() {
    val body = ResponseBody.create(MediaType.parse("application/json"), "Something went wrong")
    val expectedResponse = Response.error<Response>(500, body)
    `when`(endPoint.getDaily()).thenReturn(Single.error(HttpException(expectedResponse)))

    repo.fetchCustomerDetail()
            .test()
            .assertValueCount(0)
            .assertError { it is HttpException }

    verify(endPoint).getCustomerDetail()
}