NotificationServiceTest.kt

class NotificationServiceTest : Spek({
    describe(".notify") {
        context("when message creation fails") {
            // constants
            val messagingServiceId = "message-service-id"
            val errorCode = 9
            val errorMessage = "error message"


            val restClient = mock<TwilioRestClient>()
            val secretRepository = mock<SecretRepository> {
                on { getTwilloMessagingServiceId() } doReturn messagingServiceId
            }

            val notificationService = NotificationService(restClient, secretRepository)
            val notificationRequest = NotificationRequest("+66", "839992233", "text")

            // Assign a lambda to val directly
            val creator: MessageCreatorFactory = { _, _, _ ->
                mock {
                    on { create(restClient) } doReturn Message.fromJson(
                            """
                                {
                                  "error_code": $errorCode,
                                  "error_message": "$errorMessage",
                                  "status": "failed"
                                }
                            """.trimIndent(), jacksonObjectMapper())
                }
            }

            // `::` is not needed anymore
            val result = notificationService.notify(notificationRequest, creator)

            it("returns `NotificationFailed` with error code and error message") {
                assertThat(result).isEqualTo(NotificationFailed(errorCode, errorMessage))
            }
        }
    }
})