iOS Unit Testing - UAMobile

Transcript

1. Unit Testing
2. What is Testing For? What is Unit Test? Verifications XCTest Dependency Injection Mocks XCTest Xcode 6 API dealloc Unit Testing Unit Testing What Is Testing For?
3. What is Testing For?
4. What is Testing For? Testing can show that the product works!
5. What is Unit Test?
6. What is Unit Test? Unit tests are small pieces of code that test the behaviour of other code.
7. A test is not a unit test if: • It talks to the database • It communicates across the network • It touches the file system • It can't run at the same time as any of your other unit tests • You have to do special things to your environment (such as editing config files) to run it.
8. A good unit test is: • Able to be fully automated • Tests a single logical concept in the system • Consistently returns the same result • Maintainable and order-independent • Independent • Runs fast • Readable • Trustworthy
9. Verifications
10. Types of Verifications •Return Value •State •Behaviour
11. Types of Verifications SUT
12. Types of Verifications SUT Behaviour (Indirect Outputs) DOC
13. Types of Verifications SUT Setup Exercise Verify Tear Down Behaviour (Indirect Outputs) DOC
14. Return Value Verification We inspect the value returned from the system under test and compare it to the expected state. SUT Setup Exercise Verify Tear Down Behaviour (Indirect Outputs) DOC
15. State Verification We inspect the state of the system under test after it has been exercised and compare it to the expected state. SUT Setup Exercise Verify Tear Down Behaviour (Indirect Outputs) DOC State
16. SUT Behaviour Verification We capture the indirect outputs of the SUT as they occur and compare them to the expected behaviour. Setup Exercise Verify Tear Down Behaviour (Indirect Outputs) DOC
17. SUT Behaviour Verification We capture the indirect outputs of the SUT as they occur and compare them to the expected behaviour. Setup Exercise Verify Tear Down Behaviour (Indirect Outputs) Fake Verify
18. XCTest
19. XCTest • Provided by Xcode
20. XCTest • Provided by Xcode • New iOS application projects automatically include a unit testing target
21. XCTest • Provided by Xcode • New iOS application projects automatically include a unit testing target • Test classes do not have a header file
22. XCTest • Provided by Xcode • New iOS application projects automatically include a unit testing target • Test classes do not have a header file • It’s not necessary to add application’s source files to the XCTest Target
23. XCTest • Provided by Xcode • New iOS application projects automatically include a unit testing target • Test classes do not have a header file • It’s not necessary to add application’s source files to the XCTest Target • Each test case is a method with prefix test
24. XCTest • Provided by Xcode • New iOS application projects automatically include a unit testing target • Test classes do not have a header file • It’s not necessary to add application’s source files to the XCTest Target • Each test case is a method with prefix test • Since Xcode 5 allows to run tests from the editor
25. XCTest Flow Set Up Tear Down Test - (void)setUp { [super setUp]; // This method is called before the invocation of each test method in the class. } - (void)tearDown { // This method is called after the invocation of each test method in the class. [super tearDown]; } - (void)testExample { XCTFail(@"No implementation for \"%s\"", __PRETTY_FUNCTION__); }
26. @interface ConverterModelTests : XCTestCase { ConverterModel* sut; } @end @implementation ConverterModelTests - (void)setUp { [super setUp]; sut = [ConverterModel new]; } - (void)tearDown { sut = nil; [super tearDown]; } - (void)testMakeConversionWithModeMilesToKilometers { // Arrange sut.value = @(1); // Act [sut makeConversionWithMode:ConverterModeMilesToKm]; // Assert XCTAssertTrue([sut.text isEqualToString:@"1.609344"], @"should convert"); } @end
27. - (void)viewDidLoad { [super viewDidLoad]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(someAction:) name:kSomeNotification object:nil]; }
28. - (void)viewDidLoad { [super viewDidLoad]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(someAction:) name:kSomeNotification object:nil]; } - (void)testViewDidLoadAddsObserverForSomeNotification { // Arrange // Act // Assert }
29. Dependency Injection
30. Dependency Injection is a software design pattern that implements passing a service to a client, rather than allowing a client to build or find the service.
31. Constructor Injection the dependencies are provided through a class constructor - (id)initWithNotificationCenter:(NSNotificationCenter *)notificationCenter
32. @property (nonatomic, weak) NSUserDefaults* userDefaults; Setter Injection the client exposes a setter method that the injector uses to inject the dependency
33. Dependency Injection providing an instance variable for dependency
34. - (void)viewDidLoad { [super viewDidLoad]; [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(someAction:) name:kSomeNotification object:nil]; } Dependency - (void)testViewDidLoadAddsObserverForSomeNotification { // Arrange // Act // Assert }
35. - (id)initWithNotificationCenter:(NSNotificationCenter *)notificationCenter { self = [super init]; if(self) { _notificationCenter = notificationCenter; } return self; } - (void)viewDidLoad { [super viewDidLoad]; [_notificationCenter addObserver:self selector:@selector(someAction:) name:kSomeNotification object:nil]; } Inject Dependency
36. Mocks
37. is a fake object in the system that verifies the system under test interacted as expected with the fake object. Mock Object
38. It is common in unit tests to mock or stub collaborators of the system under test so that the test is independent of the implementation of the collaborators. Mock Object Behaviour Verification SUT Setup Exercise Verify Tear Down Behaviour (Indirect Outputs) DOC
39. It is common in unit tests to mock or stub collaborators of the system under test so that the test is independent of the implementation of the collaborators. Mock Object Behaviour Verification SUT Setup Exercise Verify Tear Down Behaviour (Indirect Outputs) Fake
40. It is common in unit tests to mock or stub collaborators of the system under test so that the test is independent of the implementation of the collaborators. Mock Object SUT Behaviour Verification Setup Exercise Verify Tear Down Behaviour (Indirect Outputs) Fake Verify
41. Test Mocks SUT communicates with the mock object, and all communication is recorded in the mock. The test uses the mock to verify that the test passes. SUT Mock Communicate Assert
42. Test Stubs Returns specified result for a message, stubs can’t fail the test. SUT Stub Communicate Assert
43. @interface ConverterViewController : UIViewController @property (nonatomic, weak) NSNotificationCenter* notificationCenter; @end @implementation ConverterViewController - (void)viewDidLoad { [super viewDidLoad]; [_notificationCenter addObserver:self selector:@selector(someAction:) name:kSomeNotification object:nil]; } @end Injected Dependency
44. @interface ConverterViewController : UIViewController @property (nonatomic, weak) NSNotificationCenter* notificationCenter; @end @implementation ConverterViewController - (void)viewDidLoad { [super viewDidLoad]; [_notificationCenter addObserver:self selector:@selector(someAction:) name:kSomeNotification object:nil]; } @end Injected Dependency Replace with a mock
45. OCMock
46. OCMock Provides •stub objects that return pre-determined values for specific method invocations •dynamic mocks that can be used to verify interaction patterns •partial mocks to overwrite selected methods of existing objects
47. Mocks // Creates a mock object that can be used as if it were an instance of // SomeClass. id mock = [OCMockObject mockForClass:[SomeClass class]]; // Tells the mock object that someMethod: should be called with an argument // that is equal to someArgument. [[mock expect] someMethod:someArgument]; // After this setup the functionality under test should be invoked // followed by [mock verify]; // When a method is called on a mock object that has not been set up with // either expect or stub the mock object will raise an exception. This // fail-fast mode can be turned off by creating a "nice" mock: id mock = [OCMockObject niceMockForClass:[SomeClass class]]; // While nice mocks will simply ignore all unexpected methods it is // possible to disallow specific methods: [[mock reject] someMethod];
48. Stubs // Tells the mock object that when someMethod: is called with // someArgument it should return aValue. [[[mock stub] andReturn:aValue] someMethod:someArgument]; // It is not possible to pass primitive types directly. [[[mock stub] andReturnValue:@YES] aMethodReturnABoolean:someArgument]; // The mock object can also throw an exception or post a notification // when a method is called [[[mock stub] andThrow:anException] someMethod:someArgument]; [[[mock stub] andPost:aNotification] someMethod:someArgument]; // If Objective-C blocks are available a block can be used to handle the // invocation and set up a return value void (^theBlock)(NSInvocation *) = ^(NSInvocation *invocation) { /* code that reads and modifies the invocation object */ }; [[[mock stub] andDo:theBlock] someMethod:[OCMArg any]];
49. @interface ConverterViewController : UIViewController @property (nonatomic, weak) NSNotificationCenter* notificationCenter; @end @implementation ConverterViewController - (void)viewDidLoad { [super viewDidLoad]; [_notificationCenter addObserver:self selector:@selector(someAction:) name:kSomeNotification object:nil]; } @end Injected Dependency
50. - (void)testViewDidLoadAddsObserver { // Arrange id mock = [OCMockObject mockForClass:[NSNotificationCenter class]]; [[mock expect] addObserver:sut selector:[OCMArg anySelector] name:kConverterModelDidUpdateNotification object:OCMOCK_ANY]; sut.notificationCenter = mock; // Act [sut viewDidLoad]; // Assert [mock verify]; } How we test this with OCMock
51. XCTest Xcode 6 API
52. XCTest Xcode 6 API •Writing tests of asynchronous operations
53. XCTest Xcode 6 API •Writing tests of asynchronous operations •Benchmark the performance of code
54. - (void)testRunAsyncCode { __block BOOL hasCalledBack = NO; [sut runAsyncCode:^(NSArray *result) { XCTAssertNotNil(result); hasCalledBack = YES; }]; NSDate *timeout = [NSDate dateWithTimeIntervalSinceNow:0.1]; while([timeout timeIntervalSinceNow] > 0 && hasCalledBack == NO) { [[NSRunLoop currentRunLoop] runMode:NSDefaultRunLoopMode beforeDate:timeout]; } XCTAssert(hasCalledBack, @"Test timed out"); Writing Tests of Asynchronous Operations }
55. - (void __block [sut hasCalledBack = }]; NSDate while [[ } XCTAssert Writing Tests of Asynchronous Operations - (void)testRunAsyncCode { [sut runAsyncCode:^(NSArray *result) { XCTAssertNotNil(result); }]; }
56. XCTestExpectation *expectation = [self expectationWithDescription:@"callback"]; [expectation fulfill]; [self waitForExpectationsWithTimeout:5.0 handler:nil]; Writing Tests of Asynchronous Operations - (void [sut }]; }
57. - (void)testPerformanceExample { // This is an example of a performance test case. [self measureBlock:^{ // Put the code you want to measure the time of here. }]; } Benchmark the Performance of Code
58. - (void)testPerformanceExample { NSString* fileName = [[NSBundle mainBundle] pathForResource:@"data" ofType:@"json"]; NSData* data = [NSData dataWithContentsOfFile:fileName]; [self measureBlock:^{ [sut precessData:data]; }]; } Benchmark the Performance of Code
59. - (void)testPerformanceExample { NSString* fileName = [[NSBundle mainBundle] pathForResource:@"data" ofType:@"json"]; NSData* data = [NSData dataWithContentsOfFile:fileName]; [self measureBlock:^{ [sut precessData:data]; }]; } Benchmark the Performance of Code [self measureBlock:^{ [sut precessData:data]; }];
60. [self measureBlock:^{ [sut precessData:data]; }]; - (void)testPerformanceExample { NSString* fileName = [[NSBundle mainBundle] pathForResource:@"data" ofType:@"json"]; NSData* data = [NSData dataWithContentsOfFile:fileName]; [self measureBlock:^{ [sut precessData:data]; }]; } Benchmark the Performance of Code
61. [self measureBlock:^{ [sut precessData:data]; }]; - (void)testPerformanceExample { NSString* fileName = [[NSBundle mainBundle] pathForResource:@"data" ofType:@"json"]; NSData* data = [NSData dataWithContentsOfFile:fileName]; [self measureBlock:^{ [sut precessData:data]; }]; } Benchmark the Performance of Code
62. [self measureBlock:^{ [sut precessData:data]; }]; - (void)testPerformanceExample { NSString* fileName = [[NSBundle mainBundle] pathForResource:@"data" ofType:@"json"]; NSData* data = [NSData dataWithContentsOfFile:fileName]; [self measureBlock:^{ [sut precessData:data]; }]; } Benchmark the Performance of Code
63. dealloc
64. dealloc create SUT delete SUT zombie - (void)setUp - (void)tearDown
65. dealloc • hook dealloc method of SUT when setup
66. dealloc • hook dealloc method of SUT when setup • record calling of the hook
67. dealloc • hook dealloc method of SUT when setup • record calling of the hook • verify if hook is called after teardown
68. Aspects
69. /// Adds a block of code before/instead/after the current `selector` for a specific instance. - (id<AspectToken>)aspect_hookSelector:(SEL)selector withOptions:(AspectOptions)options usingBlock:(id)block error:(NSError **)error; /// Called after the original implementation (default) AspectPositionAfter, /// Will replace the original implementation. AspectPositionInstead, /// Called before the original implementation. AspectPositionBefore, Aspects
70. dealloc ✓ hook dealloc method of SUT when setup • record calling of the hook • verify if hook is called after teardown Aspects
71. dealloc ✓ hook dealloc method of SUT when setup ✓ record calling of the hook • verify if hook is called after teardown Aspects instance var
72. dealloc ✓ hook dealloc method of SUT when setup ✓ record calling of the hook ✓ verify if hook is called after teardown Aspects instance var XCTAssert
73. @interface ConverterViewControllerTests : XCTestCase { ConverterViewController* sut; BOOL _sutDeallocated; } @end - (void)setUp { [super setUp]; sut = [ConverterViewController new]; _sutDeallocated = NO; [sut aspect_hookSelector:NSSelectorFromString(@"dealloc") withOptions:AspectPositionBefore usingBlock:^(id<AspectInfo> aspectInfo){ _sutDeallocated = YES; } error:nil]; } - (void)tearDown { sut = nil; XCTAssertTrue(_sutDeallocated, @"SUT is not deallocated"); [super tearDown]; } dealloc
74. @interface } @end - ( [ } - ( [ } dealloc [sut aspect_hookSelector:NSSelectorFromString(@"dealloc") withOptions:AspectPositionBefore usingBlock:^(id<AspectInfo> aspectInfo){ _sutDeallocated = YES; } error:nil];
75. What is Testing For? What is Unit Test? Verifications XCTest Dependency Injection Mocks XCTest Xcode 6 API dealloc Unit Testing
76. What is Testing For? What is Unit Test? Verifications XCTest Dependency Injection Mocks XCTest Xcode 6 API dealloc Unit Testing Demo Code https:/ /github.com/maksumko/ConverterApp" ! maksum.ko contact me: maksum.k@gmail.com
77. Sources http:/ /www.amazon.com/Art-Unit-Testing-Examples-Net/dp/1933988274 http:/ /www.amazon.com/Test-Driven-iOS-Development-Developers-Library/dp/0321774183 http:/ /www.amazon.com/Growing-Object-Oriented-Software-Guided-Tests/dp/0321503627 http:/ /martinfowler.com/articles/mocksArentStubs.html http:/ /www.objc.io/issue-1/testing-view-controllers.html http:/ /nshipster.com/xctestcase/ http:/ /blog.dadabeatnik.com/2014/07/13/asynchronous-unit-testing-in-xcode-6/#more-1114