Automated Testing with Objective-C

A quick tour of automated testing in Objective-C, starting with why we should care. Covers the basics of testing with XCTest, when to leverage mocks for testing interactions, how to test Storyboard / IB related things like instantiated view controllers or wired up actions. Follows it up with a more complex example of testing a callback block.

Originally presented at Mobile Developer Summit, Oct 10th in Bangalore, India.

Transcript

1. Automated Testing with Objective-C Ben Scheirman
2. Ben Scheirman Director of Development at ChaiOne Houston,
4. nsscreencast.com
5. Automated Tests
6. Automated Tests
7. Does your application work?
8. ˒ˑˑˑˑ
9. Application Code Automated Tests
10. Application Code Automated Tests
11. Application Code Automated Tests ✓ ✓ ✓ ✓ x x
12. Unit Tests Integration Tests Acceptance Tests
13. Unit Tests
14. Unit Tests
15. Integration Tests
16. Acceptance Tests
17. Acceptance Tests
20. What's in a test run?
21. What's in a test run? Setup Test Test Tear Down Setup Tear Down
22. What's in a test? Test Arrange Act Assert
23. What's in a test? Test
24. What's in a test? Test - (void)test_adding_numbers { Calculator *calc = [Calculator new]; int sum = [calc add:x to:y]; XCTAssertEquals(7, sum, @"math is hard :("); }
25. What's in a test? Test - (void)test_adding_numbers { Calculator *calc = [Calculator new]; int sum = [calc add:x to:y]; XCTAssertEquals(7, sum, @"math is hard :("); } Arrange
26. What's in a test? Test - (void)test_adding_numbers { Calculator *calc = [Calculator new]; int sum = [calc add:x to:y]; XCTAssertEquals(7, sum, @"math is hard :("); } Act
27. What's in a test? Test - (void)test_adding_numbers { Calculator *calc = [Calculator new]; int sum = [calc add:x to:y]; XCTAssertEquals(7, sum, @"math is hard :("); } Assert
28. 1 assertion per test
30. Unit Tests come default on Xcode 5
32. ⌘U
34. Demo: Guess the number game
35. How do we know what number it will generate?
36. Game
37. Game RNG
38. Game RNG
39. Game RNG
40. Game RNG NG Stub
41. Demo: Stubbing with OCMock
42. What about... View Controllers? Interface Builder? Storyboards?
43. DETOUR AHEAD Behavior Driven Development
44. GIVEN WHEN THEN
45. GIVEN WHEN THEN Some Behavior
46. GIVEN WHEN THEN Some Behavior I do X
47. GIVEN WHEN THEN Some Behavior I do X Y should happen
48. SpecBegin(CalculatorSpec) describe(@"Calculator", ^{ __block Calculator *_calc; beforeEach(^{ _calc = [Calculator new]; }); it(@"should add two numbers", ^{ int sum = [_calc add:5 to:7]; expect(sum).to.equal(12); }); }); SpecEnd Specta / Expecta
49. Kiwi expect(sum).to.equal(12); [theValue(sum) should] equal:theValue(12)]; Expecta
50. Kiwi Leverage OCMock for mocks & stubs Built-in powerful mocking & stubbing functionality Expecta
51. UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil]; UINavigationController *nav = [mainStoryboard instantiateInitialViewController]; ViewController *vc = (ViewController *)[nav visibleViewController]; UIView *view = vc.view; expect(view).toNot.beNil(); Testing Storyboards
52. UIButton *button = _vc.loginButton; NSArray *actions = [button actionsForTarget:_vc forControlEvent:UIControlEventTouchUpInside ]; expect(actions[0]).to.equal(@"loginTapped:"); Testing Wired Actions
53. Testing Block Based interaction VC Login Service External API
54. Testing Block Based interaction VC Login Service External API
55. Testing Block Based interaction VC Login Service External API ^{ } ^(User *user){ if (user) { NSLog(@"Logged in!"); } else { NSLog(@"Invalid login..."); } }
56. Testing Block Based interaction VC Login Service External API ^{ } ^(User *user){ if (user) { NSLog(@"Logged in!"); } else { NSLog(@"Invalid login..."); } }
57. VC Login Service External API ^{ }
58. VC Login Service External API ^{ } System
59. VC Login Service External API ^{ } System
60. Step 1: Verify Login Service is called
61. describe(@"logging in", ^{ it(@"should verify username & password w/ login svc", ^{ id mockLoginService = [OCMockObject mockForClass:[LoginService class]]; [[mockLoginService expect] verifyUsername:@"user1" password:@"password1" completion: [OCMArg any]]; _vc.loginService = mockLoginService; _vc.usernameTextField.text = @"user1"; _vc.passwordTextField.text = @"password1"; [_vc loginTapped:nil]; [mockLoginService verify]; }); });
62. describe(@"logging in", ^{ it(@"should verify username & password w/ login svc", ^{ id mockLoginService = [OCMockObject mockForClass:[LoginService class]]; [[mockLoginService expect] verifyUsername:@"user1" password:@"password1" completion: [OCMArg any]]; _vc.loginService = mockLoginService; _vc.usernameTextField.text = @"user1"; _vc.passwordTextField.text = @"password1"; [_vc loginTapped:nil]; [mockLoginService verify]; }); });
63. Step 2: Define the behavior when the login service calls back
64. Step 2: Define the behavior when the login service calls back 2 cases: success & failure
65. describe(@"logging in", ^{ it(@"should welcome the user when the login is valid", ^{ id mockLoginService = [OCMockObject mockForClass:[LoginService class]]; [[mockLoginService expect] verifyUsername:[OCMArg any] password:[OCMArg any] completion:... ]; _vc.loginService = mockLoginService; [_vc loginTapped:nil]; [mockLoginService verify]; }); });
66. describe(@"logging in", ^{ it(@"should welcome the user when the login is valid", ^{ id mockLoginService = [OCMockObject mockForClass:[LoginService class]]; [[mockLoginService expect] verifyUsername:[OCMArg any] password:[OCMArg any] completion:... ]; _vc.loginService = mockLoginService; [_vc loginTapped:nil]; [mockLoginService verify]; }); });
67. [[mockLoginService expect] verifyUsername:[OCMArg any] password:[OCMArg any] completion:[OCMArg checkWithBlock:^BOOL(id completionBlock) { // fake login successful for a user id mockUser = [OCMockObject mockForClass:[User class]]; completionBlock(mockUser); return YES; // signify that this argument is valid }]];
68. Where to go from here? Explore Acceptance Test Frameworks: KIF Frank UIAutomation
69. Some Parting Tips... If it's hard to test, improve your design
70. Some Parting Tips... If it's hard to test, improve your design Try to test 1 thing
71. Some Parting Tips... If it's hard to test, improve your design Try to test 1 thing Write tests first to avoid creating untestable designs
72. Some Parting Tips... If it's hard to test, improve your design Try to test 1 thing Write tests first to avoid creating untestable designs Use a continuous integration server
73. Some Parting Tips... If it's hard to test, improve your design Try to test 1 thing Write tests first to avoid creating untestable designs Use a continuous integration server PRACTICE!
74. Thank you! Ben Scheirman @subdigital benscheirman.com