How to make your unit tests Spektacular

Transcript

1. How to make your unit tests Spektacular
2. Spek
3. Spek
4. Spek
5. Hello JUnit my old friend
6. Our JUnit test structure @Test fun test_name() { //given set up context here (mocks, variables, prerequisites etc.) //when execute action here //then assertions go here }
7. Testing circles of hell 1. Naming hell 2. Context hell 3. Assertion hell
8. Naming Hell @Test public void validateFacebookAccessTokenAndLogin_CallsFacebookTokenRequestPermissionsDeniedError_WhenAllNecessaryPermissionsAre NotGranted() { . . . }
9. @Test public void should_not_enable_pay_button_when_promotion_is_applied_and_there_is_nothing_to_pay_and_credit_card_is_required() { // given givenPaymentCardWidgetInitialised(); givenPaymentDetailsWidgetInitialised(); givenNoCardSelected(); paymentDetailsPresenter.takeView(mockView); int discountPercentage = 100; boolean creditCardRequired = true; . . . // when . . . // then . . . } Context Hell
10. Context Hell @Test public void should_not_enable_pay_button_when_promotion_is_applied_and_there_is_nothing_to_pay_and_credit_card_is_required_and_the_ payment_card_widget_is_initialised_and_the_payment_details_widget_is_initialised_and_no_card_is_selected() { // given givenPaymentCardWidgetInitialised(); givenPaymentDetailsWidgetInitialised(); givenNoCardSelected(); paymentDetailsPresenter.takeView(mockView); int discountPercentage = 100; boolean creditCardRequired = true; . . . // when . . . // then . . . }
11. Context Hell @Test public void should_not_enable_pay_button_when_promotion_is_applied_and_there_is_nothing_to_pay_and_credit_card_is_required() { // given givenPaymentCardWidgetInitialised(); givenPaymentDetailsWidgetInitialised(); givenNoCardSelected(); paymentDetailsPresenter.takeView(mockView); int discountPercentage = 100; boolean creditCardRequired = true; PaymentPlan paymentPlan = createPaymentPlanBuilder().build(); Promotion promotion = createPromotionBuilder() .setCreditCardRequired(creditCardRequired) .setDiscountPercentage(discountPercentage) .setPaymentPlan(paymentPlan) .build(); Observable<Promotion> promoCodeObservable = Observable.just(promotion); // when paymentDetailsPresenter.onPromoCodeInitialised(promoCodeObservable); // then verify(mockView, never()).enablePayButton(); }
12. Context Hell @Test public void should_not_enable_pay_button() { // when paymentDetailsPresenter.onPromoCodeInitialised(promoCodeObservable); // then verify(mockView, never()).enablePayButton(); }
13. Assertion Hell @Test public void should_return_specialists() { // given DoctorModel doctorModel = getDoctorModel(); when(mockDoctorsService.getAllSpecialists()).thenReturn(Single.just(Collections.singletonList(doctorModel))); // when TestObserver<List<DoctorSimple>> assertableSubscriber = retrofitDoctorsGateway.getDoctorsOfType(DoctorType.create(DoctorType.Type.SPECIALIST)).test(); // then assertableSubscriber.assertComplete(); List<List<DoctorSimple>> onNextEvents = assertableSubscriber.values(); assertThat(onNextEvents.size()).isEqualTo(1); DoctorSimple doctorSimple = onNextEvents.get(0).get(0); assertThat(doctorSimple.getDoctorType()).isEqualTo(DoctorType.create(DoctorType.Type.SPECIALIST)); assertThat(doctorSimple.getId()).isEqualTo(String.valueOf(doctorModel.getId())); assertThat(doctorSimple.getName()).isEqualTo(doctorModel.getName()); assertThat(doctorSimple.getAvatarUrl()).isEqualTo(doctorModel.getAvatar()); assertAll(); assertableSubscriber.assertNoErrors(); }
14. Testing circles of hell 1. Naming hell 2. Context hell 3. Assertion hell
15. Execution flow hierarchy Execution flow: @Before public void setUp() {} @Test public void test1() {} setUp —> test1 @Test public void test2() {} setUp —> test2 @Test public void test3() {} setUp —> test3 @Test public void test4() {} setUp —> test4
16. Spek tastic
17. BDD • Verbose in communication • Concise in code • Putting tests in context • Creating a specification for the test subject • Documenting the subject’s behaviour
18. Spek syntax given("a patient") { // set up context here on("treating the patient") { // action goes here it("heals the patient") { // assertion (test) goes here } } }
19. Spek syntax xxx("description") { // BLOCK BODY }
20. Spek syntax given("a patient") { // set up context here on("treating the patient") { // action goes here it("heals the patient") { // assertion (test) goes here } } }
21. Spek syntax given("a patient") { // set up context here on("treating the patient") { // action goes here it("heals the patient") { // assertion (test) goes here } } }
22. Spek syntax given("a patient") { // set up context here on("treating the patient") { // action goes here it("heals the patient") { // assertion (test) goes here } } }
23. It it("tests the universe”) { true `should equal to` true }
24. On fun compute() = 6 * 7 on("running the ultimate computation") { val actualAnswer = compute() it("should equal 42") { actualAnswer `should be` 42 } it("should be divisible by 2") { actualAnswer % 2 `should be` 0 } }
25. Given given("the number 6") { val x = 6 given("the number 7") { val y = 7 on(“multiplying") { val actualAnswer = multiply(x, y) it("should equal 42") { actualAnswer `should be` 42 } } } }
26. given("the number 2") { val x = 2 on("squaring") { val actualAnswer = squared(x) it("should equal 4") { actualAnswer `should be` 4 } } on(“cubing") { val actualAnswer = cubed(x) it("should equal 8") { actualAnswer `should be` 8 } } }
27. State in tests val subject = SubjectUnderTest() it("checks the subject instance") { println("Instance: $subject") } it("checks the subject instance again") { println("Instance again: $subject") } Output Instance: randoms.SubjectUnderTest@3bb9a3ff Instance again: randoms.SubjectUnderTest@3bb9a3ff
28. Memoized val subject by memoized { SubjectUnderTest() } it("checks the subject instance") { println("Instance: $subject") } it("checks the subject instance again") { println("Instance again: $subject") } Output Instance: randoms.SubjectUnderTest@59309333 Instance again: randoms.SubjectUnderTest@222545dc
29. val subject by memoized { SubjectUnderTest() } on("action 1") { println("On instance 1: $subject") it("checks the subject instance") { println("It instance 1: $subject") } } on("action 2") { println("On instance 2: $subject") it("checks the subject instance again") { println("It instance 2: $subject") } } Output On instance 1: randoms.SubjectUnderTest@67d48005 It instance 1: randoms.SubjectUnderTest@67d48005 On instance 2: randoms.SubjectUnderTest@478190fc It instance 2: randoms.SubjectUnderTest@478190fc
30. val subject by memoized { SubjectUnderTest() } given("context 1") { println("Given instance 1: $subject") it("checks the subject instance") { println("It instance 1: $subject") } } given("context 2") { println("Given instance 2: $subject") it("checks the subject instance again") { println("It instance 2: $subject") } } Output Given instance 1: randoms.SubjectUnderTest@6a28ffa4 Given instance 2: randoms.SubjectUnderTest@6a28ffa4 It instance 1: randoms.SubjectUnderTest@6a28ffa4 It instance 2: randoms.SubjectUnderTest@222545dc
31. Due to how Spek is structured, group scopes are eagerly evaluated during the discovery phase. Any logic that needs to be evaluated before and/or after test scopes should be done using fixtures (…)
32. val subject by memoized { SubjectUnderTest() } given("context 1") { beforeEachTest { println("Given instance 1: $subject") } it("checks the subject instance") { println("It instance 1: $subject") } } given("context 2") { beforeEachTest { println("Given instance 2: $subject") } it("checks the subject instance again") { println("It instance 2: $subject") } } Output Given instance 1: randoms.SubjectUnderTest@895e367 It instance 1: randoms.SubjectUnderTest@895e367 Given instance 2: randoms.SubjectUnderTest@2b72cb8a It instance 2: randoms.SubjectUnderTest@2b72cb8a
33. Test execution order 1. Discovery - all given blocks are executed first 2. Execution: For each it: 1. beforeEachTest sections of containing givens 2. Containing on is executed 3. it is executed
34. Inside a given: 1. To instantiate variables, always use memoized 2. Everything else should be in beforeEachTest
35. Our rules for well written speks 1. Describe the behaviour, not the implementation 2. One assertion per it 3. One action per on 4. One statement per given (ideally!) 5. Everything in a given should be in beforeEachTest or use memoized
36. class CreatePasswordValidatorSpek : Spek({ val mockContext by memoized { mock<Context>() } val createPasswordValidator by memoized { CreatePasswordValidator(mockContext) } val INVALID_PASSWORD = "nonvalidpassword" val PATIENT_ID = "patient_id" val ERROR_MESSAGE = "message" given("an error message is returned") { beforeEachTest { whenever(mockContext.getString(any())).thenReturn(ERROR_MESSAGE) } given("a non valid password request") { val createPasswordRequest by memoized { CreatePasswordRequest.builder() .setPassword(INVALID_PASSWORD) .setPatientId(PATIENT_ID) .build() } on("validation") { val testObserver = createPasswordValidator.validate(createPasswordRequest).test() it("returns a validation exception") { testObserver.assertError(InvalidPasswordException::class.java) } it("sets the error message to \"$ERROR_MESSAGE\"") { testObserver.errors()[0].message `should be` ERROR_MESSAGE } } } } })
38. Spek drawbacks
39. Great tools that allow focusing on testing behaviour instead of implementation
40. So much easier to read the tests
41. Allows to create clean, concise and expressive tests
42. I love how you can create a test skeleton for the whole class, and then write all the mocks and verifications in it
43. The test outputs are just plain english and you can go straight to the error when it fails
44. Tests have structure that allows to easily check which scenarios are covered and which are lacking tests
45. I’m amazed at how well Spek tests scale compared to traditional tests
46. Questions? • https://github.com/Rosomack/SpekExamples • http://spekframework.org/docs/latest/#_overview • https://github.com/spekframework/spek • http://hadihariri.com/2012/04/11/what-bdd-has-taught-me/ • https://github.com/mannodermaus/android-junit5
47. We’re hiring! Presented by Mikolaj Leszczynski Say hi on Twitter & Medium! : @TheAngroid