Unit testing

Introduction to Unit testing tools in Android

Transcript

1. Dmytro Khmelenko Software Engineer 3 March 2017
2. Unit testing is a software testing method by which individual units of source code, program modules are tested to determine whether they are fit for use 2
3. JUnit is a simple framework to write repeatable tests • Annotations (@Test, @Ignore) • Assertions (assertEquals(), assertThat()) • Test Runners • Categories • … and more 3
4. 4 @Test public void testLoginParsing(){ CoreUserResponse coreUserResponse = readCoreUserDataFromFile("/user-v1.json"); assertNotNull(coreUserResponse.getCoreUser()); assertNotNull(coreUserResponse.getAuth()); assertEquals("DAT", coreUserResponse.getCoreUser().getFirstName()); assertEquals("d@t.com", coreUserResponse.getCoreUser().getEmail()); assertFalse(coreUserResponse.getCoreUser().getEmailsAllowed()); }
5. Its main goal is to improve test code readability and make maintenance of tests easier. • Extended Hamcrest matchers (esp. for arrays & iterables) • Extended comparisons • Collecting assertion errors • Testing Guava 5
6. 6 @Test public void testParseClaim() { Claim claim = loadClaimFromFile(“/claims.json"); assertThat(claim.productType()).isEqualTo("training-coach"); assertThat(claim.subscription()).isNotNull(); assertThat(claim.subscription().status()).isEqualTo("active"); }
7. 7 @Test public void performedAtParsedCorrectly(){ List<LeaderboardItem> leaderboardItems = loadLeaderBoardFromFile(); assertThat(leaderboardItems).isNotNull() .hasSize(1); SavedTraining firstTraining = getLeaderFirstTraining(leaderboardItems.get(0)); SimpleDateFormat simpleDateFormat = new SimpleDateFormat( "yyyy-MM-dd'T'HH:mm:ss.SSS'Z'", Locale.US); simpleDateFormat.setTimeZone(TimeZone.getTimeZone("GMT")); assertThat(firstTraining.getPerformedAt()).isNotNull() .withDateFormat(simpleDateFormat) .isEqualTo("2014-07-21T13:10:00.389Z"); }
8. A dependency is an object that can be used (a service). An injection is the passing of a dependency to a dependent object (a client) that would use it. 8
9. 9 public class ReleaseCorePaymentManager implements CorePaymentManager { private final PaymentApi paymentApi; private final GooglePaymentManager googlePaymentManager; public ReleaseCorePaymentManager(PaymentApi paymentApi, GooglePaymentManager googlePaymentManager) { this.paymentApi = paymentApi; this.googlePaymentManager = googlePaymentManager; } }
10. Mocking framework that allows the creation of double (mock) objects for unit testing. Main purpose is Test-Driven-Development (TDD) and Behavior-Driven-Development (BDD) 10
11. • mock() – creates a mock object of the class. Default behavior of the class is do nothing, if no stub. • spy() – creates a real object of the class. Default behavior of the class is the call real method, if no stub. 11
12. 12 public class TestReleaseCorePaymentManager { private ReleaseCorePaymentManager underTest; private GooglePaymentManager googlePaymentManager; private PaymentApi mockPaymentApi; @Before public void setUp(){ mockPaymentApi = mock(PaymentApi.class); googlePaymentManager = mock(GooglePaymentManager.class); underTest = new ReleaseCorePaymentManager(mockPaymentApi, googlePaymentManager); } }
13. 13 @RunWith(RobolectricTestRunner.class) @Config(constants = BuildConfig.class, sdk = BuildConfig.MIN_SDK_VERSION) public class TestGooglePaymentManager { private static final String TEST_PUBLIC_KEY = "TestPublicKey"; private GooglePaymentManager underTest; @Before public void setUp() throws Exception { Context context = ShadowApplication.getInstance().getApplicationContext(); underTest = spy(new GooglePaymentManager(context, TEST_PUBLIC_KEY)); }
14. 14 @RunWith(RobolectricTestRunner.class) @Config(constants = BuildConfig.class, sdk = BuildConfig.MIN_SDK_VERSION) public class TestGooglePaymentManager { private static final String TEST_PUBLIC_KEY = "TestPublicKey"; private IabHelper iabHelper; private GooglePaymentManager underTest; @Before public void setUp() throws Exception { Context context = ShadowApplication.getInstance().getApplicationContext(); underTest = spy(new GooglePaymentManager(context, TEST_PUBLIC_KEY)); iabHelper = mock(IabHelper.class); when(underTest.getIabHelper()).thenReturn(iabHelper); } }
15. • thenReturn() – stubbing the response of non-void function of the mock. • thenThrow() – stubbing throwing exception on the call of the function. • doAnswer() – stubbing void methods of the mock. 15
16. 16 @Test public void testGetInAppProductsSuccess() { List<Product> products = loadProductsFromFile(); when(mockPaymentApi.getProducts()).thenReturn(products); Inventory inventory = loadInventoryFromFile(); when(googlePaymentManager.fetchInAppInventory()).thenReturn(inventory); InAppProductContainder inAppProducts = underTest.getInAppProductContainer(); // asserts… }
17. 17 @Test public void testFetchInAppInventoryFailed() { IabResult exceptionResult = new IabResult(IabHelper.ERROR_FAILED, "error"); IabException exception = new IabException(exceptionResult); List<String> justProductIds = new ArrayList<>(); IabHelper helper = underTest.getIabHelper(); when(helper.queryInventory(true, justProductIds)).thenThrow(exception); underTest.fetchInAppInventory(justProductIds); // asserts, verification… }
18. 18 public class IabHelper { public void startSetup(IabHelperListener listener) { // establishing connection with service listener.onIabSetupFinished(new IabResult(RESPONSE_RESULT_OK, "Success")); } } @Test public void testSetupSuccess() { final IabResult result = new IabResult(IabHelper.RESPONSE_RESULT_OK, "Success"); IabHelper helper = underTest.getIabHelper(); doAnswer(new Answer<Void>() { public Void answer(InvocationOnMock invocation) throws Throwable { ((IabHelperListener) invocation.getArguments()[0]).onSetupFinished(result); return null; } }).when(helper).startSetup(isA(IabHelperListener.class)); underTest.setup(); // asserts, verification… }
19. • eq() – checks that the argument equals to object according to its equals() method. • isA() – checks that the argument is an instance of T, implying it is non-null. • any() – doesn’t do type checks with the given parameter, it is only there to avoid casting in your code. 19
20. 20 @Test public void testUserLoginSuccess() { User user = getUserFromFile(); when(mMockUserManager.login(eq(USERNAME), eq(PASSWORD))) .thenReturn(Observable.just(user)); // calls and verification } eq() checks that the argument equals to object according to its equals() method
21. isA(T.class) checks that the argument is an instance of T, implying it is non-null. 21 @Test public void testGetInAppProductsSuccess() { List<Product> product = getProductsFromFile(); when(mockPaymentApi.getProducts(eq("en"), isA(BrandType.class))).thenReturn(product); // calls and verification }
22. Any() doesn’t do type checks with the given parameter, it is only there to avoid casting in your code. This might however change (type checks could be added) in a future major release. 22 @Test public void testGetInAppProductsSuccess() throws Exception { List<Product> product = getProductsFromFile(); when(mockPaymentApi.getProducts(eq("en"), any(BrandType.class))).thenReturn(product); // calls and verification }
23. • ArgumentCaptor – captures argument values for further assertions. • verify() – checks interactions on the mock object. 23
24. 24 @Test public void testGetProductsSuccess() { ProductResponse response = loadProductResponseFromFile(); when(apiService.getProducts(any(String.class)) .thenReturn(Observable.just(response)); ProductsRequest request = new ProductsRequest(BrandType.TRAINING, "en"); underTest.getProducts(request); ArgumentCaptor<String> brandType = ArgumentCaptor.forClass(String.class); verify(apiService).getProducts(brandType.capture()); assertThat(brandType.getValue()).isNotNull(); assertThat(brandType.getValue()).isEqualTo("training-coach"); }
25. 25 @Test public void testPurchaseVerifyCoach() { Observable<Claim> claims = loadClaimsFromFile(); when(mockPaymentApi.getClaims()).thenReturn(claims); underTest.purchase(BrandType.TRAINING, product); verify(mockPaymentApi, times(1)).getClaims(); verifyNoMoreInteractions(mockPaymentApi); }
26. • You will want to test the observables, meaning not only the observables you built, but also the resulting composition of the various operators you may want to apply to them. • Given a certain observable (or its mock), you will want to test how the rest of your application behaves while triggered by the subscription. 26
27. 27 @Before public void setUp() { RxJavaHooks.setOnComputationScheduler(scheduler -> Schedulers.immediate()); RxJavaHooks.setOnIOScheduler(scheduler -> Schedulers.immediate()); } @After public void after() { RxJavaHooks.reset(); }
28. 28 @Test public void testPurchaseCoachExists() throws Exception { SkuDetails product = getProductFromFile(); Observable<Claim> claims = getDataFromFile(); when(mockPaymentApi.getClaims()).thenReturn(claims); Receipt receipt = getExpectedReceiptFromFile(); Observable<Receipt> purchaseObs = underTest.purchase(BrandType.TRAINING, product); TestSubscriber<Receipt> subscriber = new TestSubscriber<>(); purchaseObs.subscribe(subscriber); subscriber.assertValue(receipt); subscriber.assertCompleted(); }
29. 29 @Test public void testPurchaseCoachExists() throws Exception { SkuDetails product = getProductFromFile(); Observable<Claim> claims = getDataFromFile(); when(mockPaymentApi.getClaims()).thenReturn(claims); Receipt receipt = getExpectedReceiptFromFile(); Observable<Receipt> purchaseObs = underTest.purchase(BrandType.TRAINING, product); TestSubscriber<Receipt> subscriber = new TestSubscriber<>(); purchaseObs.subscribe(subscriber); subscriber.assertValue(receipt); subscriber.assertCompleted(); Receipt actualReceipt = subscriber.getOnNextEvents().get(0); assertThat(actualReceipt.isPurchased()).isFalse(); }
30. 30 @Test public void testGetInappProductFails() { PaymentException exception = new PaymentException( PaymentErrorCode.BACKEND_PRODUCTS_ARE_EMPTY); when(mockPaymentApi.getProducts("en", BrandType.TRAINING)) .thenReturn(Observable.error(exception); Observable<InAppProductContainer> inAppProducts = underTest.getInAppProductContainer(BrandType.TRAINING); TestSubscriber<InAppProductContainer> subscriber = new TestSubscriber<>(); inAppProducts.subscribe(subscriber); PaymentException actualEx = (PaymentException)subscriber.getOnErrorEvents().get(0); assertEquals(PaymentErrorCode.BACKEND_PRODUCTS_ARE_EMPTY, actualEx.getErrorCode()); subscriber.assertNotCompleted(); }
31. 1. http://junit.org/junit4/ 2. http://joel-costigliola.github.io/assertj/ 3. http://site.mockito.org/ 4. http://reactivex.io/RxJava/javadoc/rx/observers/TestSubscriber.html 5. http://fedepaol.github.io/blog/2015/09/13/testing-rxjava-observables-subscriptions/ 31