Rambler.iOS #8 - Чистые unit-тесты

Чистые unit-тесты

What makes a clean test?

Three things. Readability, readability, and readability.

Robert C. Martin, «Clean Code»

#добришко

- (void)testLoadAlbums { NSError *err1 = [NSError errorWithDomain:@"" code:123 userInfo:nil];

OCMStub([self.provider getAlbumsWithResultBlock:OCMOCK_ANY]).andDo(block);

[self waitForExpectationsWithTimeout:1. handler:^(NSError *localError) { OCMVerify([self.provider getAlbumsWithResultBlock:OCMOCK_ANY]); }]; }

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- (void)testDeletingMessages { NSMutableArray *messages = [NSMutableArray new]; NSManagedObjectContext *ctx = [NSManagedObjectContext MR_contextForCurrentThread]; [messages addObject:message]; } XCTestExpectation *expectation = [self expectationWithDescription: [NSString stringWithFormat:@"%s", __PRETTY_FUNCTION__]]; [self.service deleteMessages:messages withResultBlock:^(NSError *error) { [expectation fulfill]; }];

}

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}

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}

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}

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Зачем нужны чистые тесты

Как писать чистые тесты

Рефакторим тест

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/** @author Egor Tolstoy Метод возвращает закешированные результаты поиска для определенной поисковой строки @param searchTerm Поисковая строка @return Результаты поиска */ - (NSArray *)obtainSearchResultsForSearchTerm:(NSString *)searchTerm;

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@implementation PeopleServiceImplementationTests

- (void)testThatService {}




@end

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@end

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@end

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@end

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@end

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/** Метод возвращает закешированные результаты поиска для определенной поисковой строки @param searchTerm Поисковая строка @return Результаты поиска */

+ ...ServiceReturnsCachedSearchResultsForCorrectQuery ...ServiceReturnsNilWhenNoResults ...ServiceReturnsNilForInvalidCharacters ...ServiceInterpretsDashesAsUnderscores

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Грязные тесты > Тяжело поддерживать >

Удаление тестов > Падает качество проекта

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Чистый тест

предметно-ориентированный язык

без лишнего контекста

тестируется одно поведение системы

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Предметно-ориентированный язык

Хорошо XCTAssertEqualObjects(testAlbumError, expectedError); - (void)testThatServiceReturnsNilWhenNoResults [self setupStateWithBlockedUser];

Плохо XCTAssertEqualObjects(err1, err2); - (void)testNil [self setupTestData];

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Нет лишнего контекста

Хорошо [self stubServiceCompletionBlockWithError:error]; - (void)setUp {}

Плохо ...[invocation getArgument:&result atIndex:3];...

... self.interactor.output = OCMProtocolMock(...);...

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Тестируем одно поведениеХорошо ... XCTAssertTrue(viewReloaded); XCTAssertTrue(newDataIsShown);

Плохо ... XCTAssertTrue(newUserSaved); XCTAssertFalse(viewReloaded); XCTAssertNil([self.service obtainSearchHistory]);

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OCMExpect([self.mockView setupInitialStateWithMenuItems:[OCMArg checkWithBlock:^BOOL(NSArray *menuItems) { __block BOOL correctSelectors = YES; [menuItems enumerateObjectsUsingBlock:^(ItemViewModel *menuItem, NSUInteger idx, BOOL stop) { NSString *expectedSelector = selectors[idx]; if (![expectedSelector isEqualToString:NSStringFromSelector(menuItem.tapSelector)]) { correctSelectors = NO; } }]; return correctSelectors && menuItems.count == selectors.count; }]]);

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OCMExpect([self.mockView setupInitialStateWithMenuItems:[OCMArg checkWithBlock:^BOOL(NSArray *menuItems) { __block BOOL correctSelectors = YES; [menuItems enumerateObjectsUsingBlock:^(ItemViewModel *menuItem, NSUInteger idx, BOOL stop) { NSString *expectedSelector = selectors[idx]; if (![expectedSelector isEqualToString:NSStringFromSelector(menuItem.tapSelector)]) { correctSelectors = NO; } }]; return correctSelectors && menuItems.count == selectors.count; }]]);

self.mockView = [MockMenuView new]; XCTAssertTrue(self.mockView.areAllSelectorsCorrect);

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// Случайная строка NSString *string = [[NSUUID UUID] UUIDString];

// Произвольная ошибка NSError *error = [NSError errorWithDomain:@"TestDomain" code:0 userInfo:nil];

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// Случайная строка NSString *string = [[NSUUID UUID] UUIDString];

// Произвольная ошибка NSError *error = [NSError errorWithDomain:@"TestDomain" code:0 userInfo:nil];

NSString *string = [MockGenerator generateMockString]; NSError *error = [MockGenerator generateMockError];

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- (void)setUp { [super setUp]; RamblerInitialAssemblyCollector *collector = [RamblerInitialAssemblyCollector new]; NSArray *assemblyClasses = [collector collectInitialAssemblyClasses]; NSMutableArray *collaboratingAssemblies = [NSMutableArray array]; for (Class assemblyClass in assemblyClasses) { if (assemblyClass == [NetworkAssembly class]) { continue; } TyphoonAssembly *assembly = [assemblyClass new]; [collaboratingAssemblies addObject:assembly]; } NetworkAssembly *networkAssembly = [NetworkAssembly new]; [networkAssembly activateWithCollaboratingAssemblies:collaboratingAssemblies]; [networkAssembly inject:self]; }

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- (void)setUp { [super setUp]; RamblerInitialAssemblyCollector *collector = [RamblerInitialAssemblyCollector new]; NSArray *assemblyClasses = [collector collectInitialAssemblyClasses]; NSMutableArray *collaboratingAssemblies = [NSMutableArray array]; for (Class assemblyClass in assemblyClasses) { if (assemblyClass == [NetworkAssembly class]) { continue; } TyphoonAssembly *assembly = [assemblyClass new]; [collaboratingAssemblies addObject:assembly]; } NetworkAssembly *networkAssembly = [NetworkAssembly new]; [networkAssembly activateWithCollaboratingAssemblies:collaboratingAssemblies]; [networkAssembly inject:self]; [MagicalRecord setupInMemoryCoreData]; }

- (void)setUp { [self setUpWithAssemblyClass:[NetworkAssembly class]]; }

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- (void)testThatServiceLoadsSessionProfileSuccessfully { NSError *resultError;

// большой блок логики загрузки профиля XCTAssertNil(resultError); }

- (void)testThatServiceLoadsSessionProfileWithError { NSError *expectedError = [MockObjectsFactory generateGeneralError];

// большой блок логики загрузки профиля XCTAssertEqualObjects(resultError, expectedError); }

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- (void)testThatServiceLoadsSessionProfileSuccessfully { NSError *resultError;

// большой блок логики загрузки профиля XCTAssertNil(resultError); }

- (void)testThatServiceLoadsSessionProfileWithError { NSError *expectedError = [MockObjectsFactory generateGeneralError];

// большой блок логики загрузки профиля XCTAssertEqualObjects(resultError, expectedError); }

- (void)testThatServiceLoadsProfileSuccessfully { [self verifyThatServiceLoadsProfileWithError:nil]; }

- (void)testThatServiceLoadsProfileWithError { [self verifyThatServiceLoadsProfileWithError:error]; }

- (void)verifyThatServiceLoadsProfileWithError:(id)error { ... }

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- (void)testThatPresenterStartsObservePost { NSString *postId = [MockObjectsFactory generateGeneralString]; [self.presenter configureCurrentModuleWithPostId:postId]; [self.presenter didTriggerViewReadyEvent]; OCMVerify([self.mockInteractor startObserveChangesWithPostId:postId]); }

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- (void)testThatPresenterStartsObservePost { NSString *postId = [MockObjectsFactory generateGeneralString]; [self.presenter configureCurrentModuleWithPostId:postId]; [self.presenter didTriggerViewReadyEvent]; OCMVerify([self.mockInteractor startObserveChangesWithPostId:postId]); }

- (void)testThatPresenterStartsObservePost { // given NSString *postId = [MockObjectsFactory generateGeneralString]; [self.presenter configureCurrentModuleWithPostId:postId]; // when [self.presenter didTriggerViewReadyEvent]; // then OCMVerify([self.mockInteractor startObserveChangesWithPostId:postId]); }

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OperationScheduler

queue1 queue2

NSOperation NSOperation42

NSArray *operations = self.generalQueue.operations;

for (NSOperation *generalOperation in operations) { [generalOperation addDependency:operation]; } [self.authQueue addOperation:operation];

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• Передаем initialOperation в Планировщик

• Передаем в Планировщик 5 generalOperation

• При выполнении initialOperation создает authOperation

initial > authorization > general (5x)

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- (void)testThatAuthOperationBlocksGeneralOperations { // given XCTestExpectation *expectation = [self expectationForCurrentTest]; NSMutableArray *operationNames = [NSMutableArray array]; NSString *const kAuthOperationName = @"AuthOperation"; NSString *const kInitialOperationName = @"InitialOperation"; NSString *const kGeneralOperationName = @"GeneralOperation"; NSUInteger const kGeneralOperationsCount = 5; __block NSNumber *operationCounter = @0; NSBlockOperation *authOperation = [NSBlockOperation blockOperationWithBlock:^{ dispatch_async(dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_DEFAULT, 0), ^{ @synchronized(operationNames) { [operationNames addObject:kAuthOperationName]; } [NSThread sleepForTimeInterval:0.05]; }); }]; NSBlockOperation *initialOperation = [NSBlockOperation blockOperationWithBlock:^{ @synchronized(operationNames) { [operationNames addObject:kInitialOperationName]; } [self.scheduler addAuthOperation:authOperation]; }]; // when [self.scheduler addGeneralOperation:initialOperation]; for (NSUInteger i = 0; i < kGeneralOperationsCount; i++) { NSBlockOperation *generalOperation = [NSBlockOperation blockOperationWithBlock:^{ @synchronized(operationNames) { [operationNames addObject:kGeneralOperationName]; } @synchronized(operationCounter) { operationCounter = @([operationCounter integerValue] + 1); if ([operationCounter integerValue] == kGeneralOperationsCount) { dispatch_async(dispatch_get_main_queue(), ^{ [expectation fulfill]; }); } } }]; [self.scheduler addGeneralOperation:generalOperation]; } // then [self waitForExpectationsWithTimeout:kTestExpectationTimeout handler:^(NSError *error) { XCTAssertEqualObjects(operationNames[0], kInitialOperationName); XCTAssertEqualObjects(operationNames[1], kAuthOperationName); for (NSUInteger i = 2; i < kGeneralOperationsCount; i++) { XCTAssertEqualObjects(operationNames[i], kGeneralOperationName); } }]; }

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XCTestExpectation *expectation = [self expectationWithDescription:@"Last operation fired"];

XCTestExpectation *expectation = [self expectationForCurrentTest];

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NSString *const kAuthOperationName = @"AuthOperation"; NSString *const kInitialOperationName = @"InitialOperation"; NSString *const kGeneralOperationName = @"GeneralOperation";

OperationSchedulerTestConstants.h

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NSBlockOperation *authOperation = [NSBlockOperation withBlock:^{ dispatch_async(..., ^{ @synchronized(operationNames) { [operationNames addObject:authName]; } [NSThread sleep:0.05]; }); }];

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@interface TestBlockingByAuthOperationEnvironment : NSObject

- (void)setupWithTestCase:(XCTestCase *)testCase operationsCount:(NSUInteger)operationsCount initialBlock:(Block)initialBlock;

@property NSBlockOperation *initialOperation; @property NSBlockOperation *authOperation; @property NSArray *generalOperations; @property NSArray *firedOperationNames;

@end

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TestBlockingByAuthOperationEnvironment *environment = [TestBlockingByAuthOperationEnvironment new];

[environment setupWithTestCase:self operationsCount:kGeneralOperationsCount initialBlock:^{

[self.scheduler addAuthOperation:environment.authOperation]; for (NSOperation *operation in environment.generalOperations) { [self.scheduler addGeneralOperation:operation]; } }];

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- (void)testThatAuthOperationBlocksGeneralOperations { // given NSUInteger const kGeneralOperationsCount = 5; TestBlockingByAuthOperationEnvironment *environment = [TestBlockingByAuthOperationEnvironment new];

[environment setupEnvironmentWithTestCase:self generalOperationsCount:kGeneralOperationsCount initialOperationBlock:^{ [self.scheduler addAuthOperation:environment.authOperation]; for (NSOperation *operation in environment.generalOperations) { [self.scheduler addGeneralOperation:operation]; } }]; // when [self.scheduler addGeneralOperation:environment.initialOperation]; // then [self waitForExpectationsWithTimeout:kTestExpectationTimeout handler:^(NSError *error) {

[self verifyCorrectOperationOrder:kTestOrder]; }]; }

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Предметно-ориентированный язык

Нет лишнего контекста

Тестируем одно поведение

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What makes a clean test?

Three things.

Readability, readability,

and readability.

Егор Толстой

@igrekde

Technology

Rambler.iOS #8 - Чистые unit-тесты