BDD on iOS with Kiwi

1. Behavior Driven Development in iOS Ian Murray — @synt4x — github.com/ianmurrays
2. Why? • You make sure you don’t break anything in the future • You can optimize/refactor code knowing it won’t break
3. Why Not?
4. Why Not? • It’s time-consuming
5. Why Not? • It’s time-consuming • It’s not “easy”
6. How To Make It Worth The Effort
7. How To Make It Worth The Effort • Don’t write tests for trivial things
8. How To Make It Worth The Effort • Don’t write tests for trivial things - (NSInteger)add:(NSInteger)this to:(NSInteger)that { return this + that; }
9. How To Make It Worth The Effort • Don’t write tests for trivial things • If you find a bug, write some tests to reproduce it and then fix it
10. How To Make It Worth The Effort • Don’t write tests for trivial things • If you find a bug, write some tests to reproduce it and then fix it • Don’t try and test everything, (especially UI)
11. Kiwi
12. Kiwi • BDD
13. Kiwi • BDD • Simple to install (via CocoaPods)
14. Kiwi • BDD • Simple to install (via CocoaPods) • Very complete
15. Installing
16. Installing $ [sudo] gem install cocoapods $ pod setup $ cd path/to/project $ pod init $ vim Podfile
17. Installing $ [sudo] gem install cocoapods $ pod setup $ cd path/to/project $ pod init $ vim Podfile target "BDDKiwi" do ! end ! target "BDDKiwiTests" do pod 'Kiwi/XCTest' # Xcode 5 end
18. Installing $ [sudo] gem install cocoapods $ pod setup $ cd path/to/project $ pod init $ vim Podfile target "BDDKiwi" do ! end ! target "BDDKiwiTests" do pod 'Kiwi/XCTest' # Xcode 5 end $ pod install $ open project.xcworkspace
19. Our First Spec SPEC_BEGIN(CalculatorSpec) ! describe(@"Calculator", ^{ describe(@"adding up two numbers", ^{ it(@"should add two numbers", ^{ [[theValue([Calculator add:1 to:1]) should] equal:theValue(2)]; }); }); }); ! ! SPEC_END
20. Our First Spec SPEC_BEGIN(CalculatorSpec) ! describe(@"Calculator", ^{ describe(@"adding up two numbers", ^{ it(@"should add two numbers", ^{ [[theValue([Calculator add:1 to:1]) should] equal:theValue(2)]; }); }); }); ! ! SPEC_END
21. Our First Spec SPEC_BEGIN(CalculatorSpec) ! describe(@"Calculator", ^{ describe(@"adding up two numbers", ^{ it(@"should add two numbers", ^{ [[theValue([Calculator add:1 to:1]) should] equal:theValue(2)]; }); }); }); ! ! SPEC_END
22. Our First Spec SPEC_BEGIN(CalculatorSpec) ! describe(@"Calculator", ^{ describe(@"adding up two numbers", ^{ it(@"should add two numbers", ^{ [[theValue([Calculator add:1 to:1]) should] equal:theValue(2)]; }); }); }); ! ! SPEC_END
23. Our First Spec SPEC_BEGIN(CalculatorSpec) ! describe(@"Calculator", ^{ describe(@"adding up two numbers", ^{ it(@"should add two numbers", ^{ [[theValue([Calculator add:1 to:1]) should] equal:theValue(2)]; }); }); }); ! ! SPEC_END
24. Our First Spec SPEC_BEGIN(CalculatorSpec) ! describe(@"Calculator", ^{ describe(@"adding up two numbers", ^{ it(@"should add two numbers", ^{ [[theValue([Calculator add:1 to:1]) should] equal:theValue(2)]; }); }); }); ! ! SPEC_END
25. Writing our class + (NSInteger)add:(NSInteger)first to:(NSInteger)second { return first + second; }
26. More Specs describe(@"adding up to NSNumbers", ^{ it(@"should add up to NSNumbers", ^{ [[[Calculator addNumber:@1 toNumber:@1] should] equal:@2]; }); });
27. More Specs describe(@"adding up to NSNumbers", ^{ it(@"should add up to NSNumbers", ^{ [[[Calculator addNumber:@1 toNumber:@1] should] equal:@2]; }); });
28. More Specs describe(@"adding up to NSNumbers", ^{ it(@"should add up to NSNumbers", ^{ [[[Calculator addNumber:@1 toNumber:@1] should] equal:@2]; }); });
29. More Specs describe(@"adding up to NSNumbers", ^{ it(@"should add up to NSNumbers", ^{ [[[Calculator addNumber:@1 toNumber:@1] should] equal:@2]; }); });
30. More Specs describe(@"adding up to NSNumbers", ^{ it(@"should add up to NSNumbers", ^{ [[[Calculator addNumber:@1 toNumber:@1] should] equal:@2]; }); });
31. Async Specs describe(@"asynchronously adding NSNumbers", ^{ it(@"should add up two numbers asynchronously", ^{ __block NSNumber *result; [Calculator addNumber:@1 toNumber:@1 completionHandler:^(NSNumber *_) { result = _; }]; [[expectFutureValue(result) shouldEventually] equal:@2]; }); });
32. Async Specs describe(@"asynchronously adding NSNumbers", ^{ it(@"should add up two numbers asynchronously", ^{ __block NSNumber *result; [Calculator addNumber:@1 toNumber:@1 completionHandler:^(NSNumber *_) { result = _; }]; [[expectFutureValue(result) shouldEventually] equal:@2]; }); });
33. Async Specs describe(@"asynchronously adding NSNumbers", ^{ it(@"should add up two numbers asynchronously", ^{ __block NSNumber *result; [Calculator addNumber:@1 toNumber:@1 completionHandler:^(NSNumber *_) { result = _; }]; [[expectFutureValue(result) shouldEventually] equal:@2]; }); });
34. Async Specs describe(@"asynchronously adding NSNumbers", ^{ it(@"should add up two numbers asynchronously", ^{ __block NSNumber *result; [Calculator addNumber:@1 toNumber:@1 completionHandler:^(NSNumber *_) { result = _; }]; [[expectFutureValue(result) shouldEventually] equal:@2]; }); });
35. Async Specs
36. Async Specs
37. Async Specs What if our calculation takes way longer?
38. Async Specs describe(@"asynchronously adding NSNumbers", ^{ it(@"should add up two numbers asynchronously", ^{ __block NSNumber *result; [Calculator addNumber:@1 toNumber:@1 completionHandler:^(NSNumber *_) { result = _; }]; [[expectFutureValue(result) shouldEventuallyBeforeTimingOutAfter(10)] equal:@2]; }); }); What if our calculation takes way longer?
39. Async Specs describe(@"asynchronously adding NSNumbers", ^{ it(@"should add up two numbers asynchronously", ^{ __block NSNumber *result; [Calculator addNumber:@1 toNumber:@1 completionHandler:^(NSNumber *_) { result = _; }]; [[expectFutureValue(result) shouldEventuallyBeforeTimingOutAfter(10)] equal:@2]; }); }); What if our calculation takes way longer?
40. Async Specs describe(@"asynchronously adding NSNumbers", ^{ it(@"should add up two numbers asynchronously", ^{ __block NSNumber *result; [Calculator addNumber:@1 toNumber:@1 completionHandler:^(NSNumber *_) { result = _; }]; [[expectFutureValue(result) shouldEventuallyBeforeTimingOutAfter(10)] equal:@2]; }); }); What if our calculation takes way longer? Unfortunately, not an exact science.
41. Mocks & Stubs
42. Mocks & Stubs • The Unit in Unit Testing is important.
43. Mocks & Stubs • The Unit in Unit Testing is important. • You want to test units of code and not your entire app (those would be integration tests).
44. Mocks & Stubs • The Unit in Unit Testing is important. • You want to test units of code and not your entire app (those would be integration tests). • You don’t want your tests to depend on network connectivity • Server responses should remain the same, and server should have its own Unit Tests Suite.
45. Mocks & Stubs • The Unit in Unit Testing is important. • You want to test units of code and not your entire app (those would be integration tests). • You don’t want your tests to depend on network connectivity • Server responses should remain the same, and server should have its own Unit Tests Suite. • You want tests to be fast
46. Mocks
47. Mocks • Mock objects are “fake” objects that you create on-the-fly
48. Mocks • Mock objects are “fake” objects that you create on-the-fly • They do what you configure them to do
49. Mocks • Mock objects are “fake” objects that you create on-the-fly • They do what you configure them to do • Not always useful and normally not necessary
50. Stubs
51. Stubs • Stubbing is used to switch the functionality of a method for another
52. Stubs • Stubbing is used to switch the functionality of a method for another • This way you can have an object return what you want, effectively replacing it
53. Stubs • Stubbing is used to switch the functionality of a method for another • This way you can have an object return what you want, effectively replacing it • Useful to set conditions for a given test case
54. Stubs • Stubbing is used to switch the functionality of a method for another • This way you can have an object return what you want, effectively replacing it • Useful to set conditions for a given test case • You can avoid depending on other methods
56. typedef NS_ENUM(NSUInteger, CruiserCoreStatus) { CruiserCoreStatusNormal, CruiserCoreStatusAlert, CruiserCoreStatusCritical }; ! ////////////////////////////////////////////////////////////////////// ! @interface Cruiser : NSObject ! @property (nonatomic,assign) NSUInteger speed; ! - (NSUInteger)energyLevelForCurrentSpeed; ! /** If energyLevel < 5, then returns CruiserCoreStatusNormal. If 5 <= energyLevel < 10 , then returns CruiserCoreStatusAlert. If 10 <= energyLevel , then returns CruiserCoreStatusCritical. */ - (CruiserCoreStatus)coreStatus; ! @end
57. describe(@"coreStatus", ^{ it(@"should return normal for low energy levels", ^{ Cruiser *cruiser = [Cruiser new]; [[cruiser stubAndReturn:theValue(3)] energyLevelForCurrentSpeed]; [[theValue([cruiser coreStatus]) should] equal:theValue(CruiserCoreStatusNormal)]; }); it(@"should return alert for medium energy levels", ^{ Cruiser *cruiser = [Cruiser new]; [cruiser stub:@selector(energyLevelForCurrentSpeed) andReturn:theValue(7)]; [[theValue([cruiser coreStatus]) should] equal:theValue(CruiserCoreStatusAlert)]; }); it(@"should return critical for high energy levels", ^{ Cruiser *cruiser = [Cruiser new]; [cruiser stub:@selector(energyLevelForCurrentSpeed) withBlock:^id(NSArray *params) { return theValue(15); }]; [[theValue([cruiser coreStatus]) should] equal:theValue(CruiserCoreStatusCritical)]; }); });
58. describe(@"coreStatus", ^{ it(@"should return normal for low energy levels", ^{ Cruiser *cruiser = [Cruiser new]; [[cruiser stubAndReturn:theValue(3)] energyLevelForCurrentSpeed]; [[theValue([cruiser coreStatus]) should] equal:theValue(CruiserCoreStatusNormal)]; }); it(@"should return alert for medium energy levels", ^{ Cruiser *cruiser = [Cruiser new]; [cruiser stub:@selector(energyLevelForCurrentSpeed) andReturn:theValue(7)]; [[theValue([cruiser coreStatus]) should] equal:theValue(CruiserCoreStatusAlert)]; }); it(@"should return critical for high energy levels", ^{ Cruiser *cruiser = [Cruiser new]; [cruiser stub:@selector(energyLevelForCurrentSpeed) withBlock:^id(NSArray *params) { return theValue(15); }]; [[theValue([cruiser coreStatus]) should] equal:theValue(CruiserCoreStatusCritical)]; }); });
59. describe(@"coreStatus", ^{ it(@"should return normal for low energy levels", ^{ Cruiser *cruiser = [Cruiser new]; [[cruiser stubAndReturn:theValue(3)] energyLevelForCurrentSpeed]; [[theValue([cruiser coreStatus]) should] equal:theValue(CruiserCoreStatusNormal)]; }); it(@"should return alert for medium energy levels", ^{ Cruiser *cruiser = [Cruiser new]; [cruiser stub:@selector(energyLevelForCurrentSpeed) andReturn:theValue(7)]; [[theValue([cruiser coreStatus]) should] equal:theValue(CruiserCoreStatusAlert)]; }); it(@"should return critical for high energy levels", ^{ Cruiser *cruiser = [Cruiser new]; [cruiser stub:@selector(energyLevelForCurrentSpeed) withBlock:^id(NSArray *params) { return theValue(15); }]; [[theValue([cruiser coreStatus]) should] equal:theValue(CruiserCoreStatusCritical)]; }); });
60. describe(@"coreStatus", ^{ it(@"should return normal for low energy levels", ^{ Cruiser *cruiser = [Cruiser new]; [[cruiser stubAndReturn:theValue(3)] energyLevelForCurrentSpeed]; [[theValue([cruiser coreStatus]) should] equal:theValue(CruiserCoreStatusNormal)]; }); it(@"should return alert for medium energy levels", ^{ Cruiser *cruiser = [Cruiser new]; [cruiser stub:@selector(energyLevelForCurrentSpeed) andReturn:theValue(7)]; [[theValue([cruiser coreStatus]) should] equal:theValue(CruiserCoreStatusAlert)]; }); it(@"should return critical for high energy levels", ^{ Cruiser *cruiser = [Cruiser new]; [cruiser stub:@selector(energyLevelForCurrentSpeed) withBlock:^id(NSArray *params) { return theValue(15); }]; [[theValue([cruiser coreStatus]) should] equal:theValue(CruiserCoreStatusCritical)]; }); });
61. Avoiding Network Calls
62. - (void)getLatestResourcesWithCompletionHandler:(void (^)(NSArray *resources))completion { AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager]; [manager GET:@"http://example.com/resources.json" parameters:nil success:^(AFHTTPRequestOperation *operation, id responseObject) { NSMutableArray *resources = [NSMutableArray array]; // Parse the response for (NSDictionary *resource in responseObject) { Resource *r = [Resource new]; r.name = resource[@"name"]; r.identifier = resource[@"id"]; [resources addObject:r]; } if (completion) completion(resources.copy); } failure:nil]; }
64. it(@"should return an array of resources", ^{ NSArray *mockJSON = @[ @{ @"id": @123, @"name": @"John Doe" }, @{ @"id": @124, @"name": @"Jane Doe" }, ]; // Stub AFNetworking AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager]; [AFHTTPRequestOperationManager stub:@selector(manager) andReturn:manager]; [[AFHTTPRequestOperationManager manager] stub:@selector(GET:parameters:success:failure:) withBlock:^id(NSArray *params) { // Get the success handler void (^success)(id _, id responseObject) = params[2]; // Call it with our JSON success(nil, mockJSON); return nil; // We don't care of what's returned }]; __block NSArray *response = nil; [Network getLatestResourcesWithCompletionHandler:^(NSArray *_) { response = _; }]; [[expectFutureValue([response.firstObject identifier]) shouldEventuallyBeforeTimingOutAfter(10)] equal:@123]; [[expectFutureValue([response.firstObject name]) shouldEventuallyBeforeTimingOutAfter(10)] equal:@"John Doe"]; });
65. it(@"should return an array of resources", ^{ NSArray *mockJSON = @[ @{ @"id": @123, @"name": @"John Doe" }, @{ @"id": @124, @"name": @"Jane Doe" }, ]; // Stub AFNetworking AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager]; [AFHTTPRequestOperationManager stub:@selector(manager) andReturn:manager]; [[AFHTTPRequestOperationManager manager] stub:@selector(GET:parameters:success:failure:) withBlock:^id(NSArray *params) { // Get the success handler void (^success)(id _, id responseObject) = params[2]; // Call it with our JSON success(nil, mockJSON); return nil; // We don't care of what's returned }]; __block NSArray *response = nil; [Network getLatestResourcesWithCompletionHandler:^(NSArray *_) { response = _; }]; [[expectFutureValue([response.firstObject identifier]) shouldEventuallyBeforeTimingOutAfter(10)] equal:@123]; [[expectFutureValue([response.firstObject name]) shouldEventuallyBeforeTimingOutAfter(10)] equal:@"John Doe"]; });
66. it(@"should return an array of resources", ^{ NSArray *mockJSON = @[ @{ @"id": @123, @"name": @"John Doe" }, @{ @"id": @124, @"name": @"Jane Doe" }, ]; // Stub AFNetworking AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager]; [AFHTTPRequestOperationManager stub:@selector(manager) andReturn:manager]; [[AFHTTPRequestOperationManager manager] stub:@selector(GET:parameters:success:failure:) withBlock:^id(NSArray *params) { // Get the success handler void (^success)(id _, id responseObject) = params[2]; // Call it with our JSON success(nil, mockJSON); return nil; // We don't care of what's returned }]; __block NSArray *response = nil; [Network getLatestResourcesWithCompletionHandler:^(NSArray *_) { response = _; }]; [[expectFutureValue([response.firstObject identifier]) shouldEventuallyBeforeTimingOutAfter(10)] equal:@123]; [[expectFutureValue([response.firstObject name]) shouldEventuallyBeforeTimingOutAfter(10)] equal:@"John Doe"]; });
67. it(@"should return an array of resources", ^{ NSArray *mockJSON = @[ @{ @"id": @123, @"name": @"John Doe" }, @{ @"id": @124, @"name": @"Jane Doe" }, ]; // Stub AFNetworking AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager]; [AFHTTPRequestOperationManager stub:@selector(manager) andReturn:manager]; [[AFHTTPRequestOperationManager manager] stub:@selector(GET:parameters:success:failure:) withBlock:^id(NSArray *params) { // Get the success handler void (^success)(id _, id responseObject) = params[2]; // Call it with our JSON success(nil, mockJSON); return nil; // We don't care of what's returned }]; __block NSArray *response = nil; [Network getLatestResourcesWithCompletionHandler:^(NSArray *_) { response = _; }]; [[expectFutureValue([response.firstObject identifier]) shouldEventuallyBeforeTimingOutAfter(10)] equal:@123]; [[expectFutureValue([response.firstObject name]) shouldEventuallyBeforeTimingOutAfter(10)] equal:@"John Doe"]; });
68. it(@"should return an array of resources", ^{ NSArray *mockJSON = @[ @{ @"id": @123, @"name": @"John Doe" }, @{ @"id": @124, @"name": @"Jane Doe" }, ]; // Stub AFNetworking AFHTTPRequestOperationManager *manager = [AFHTTPRequestOperationManager manager]; [AFHTTPRequestOperationManager stub:@selector(manager) andReturn:manager]; [[AFHTTPRequestOperationManager manager] stub:@selector(GET:parameters:success:failure:) withBlock:^id(NSArray *params) { // Get the success handler void (^success)(id _, id responseObject) = params[2]; // Call it with our JSON success(nil, mockJSON); return nil; // We don't care of what's returned }]; __block NSArray *response = nil; [Network getLatestResourcesWithCompletionHandler:^(NSArray *_) { response = _; }]; [[expectFutureValue([response.firstObject identifier]) shouldEventuallyBeforeTimingOutAfter(10)] equal:@123]; [[expectFutureValue([response.firstObject name]) shouldEventuallyBeforeTimingOutAfter(10)] equal:@"John Doe"]; });
69. github.com/allending/Kiwi/wiki