The document summarizes iOS testing frameworks and techniques. It discusses XCTest for unit and functional testing, OCMock for mocking objects in tests, and KIF for integration testing. It provides examples of testing asynchronous functions, singletons, and MVP architecture. The benefits of testing include specifying requirements, reducing bugs, and enforcing good architecture.

1. iOS Testing
Derrick Chao @ Loopd

2. Frameworks
• XCTest
• OCMock
• KIF

3. XCTest
• XCTest is the testing framework in Xcode
• A test method is an instance method of a
test class that begins with the prefix test
- (void)testExample {
// This is an example of a functional test case.
XCTAssert(YES, @"Pass");
XCTAssert(1+1==2);
XCTAssertTrue(1+1==2);
XCTAssertFalse(1+1==3);
}
• XCTAssert
XCTAssert(expression, …);
XCTAssertTrue(expression, …);
XCTAssertFalse(expression, ...);

4. Unit Test Example
- (void)testValidatePassword {
NSString *password1 = @"AbCd1234";
NSString *password2 = @"AbCd12";
NSString *password3 = @"ABCD";
NSString *password4 = @"AbCd1";
NSString *password5 = @"";
XCTAssertTrue([Helper validatePassword:password1]);
XCTAssertTrue([Helper validatePassword:password2]);
XCTAssertFalse([Helper validatePassword:password3]);
XCTAssertFalse([Helper validatePassword:password4]);
XCTAssertFalse([Helper validatePassword:password5]);
}

5. Test Async Function
Example
• send a message to another user
• async
• block callback

6. Test Async Function
Example
- (void)testSendMessageWithNilMessage {
XCTestExpectation *expectation =
[self expectationWithDescription:@"completion should be called"];
[Message sendMessage:nil recipientInfo:nil completion:^(id responseObject, NSError
*error) {
[expectation fulfill];
XCTAssertNotNil(error);
XCTAssert([error.userInfo[@"message"] isEqualToString:@"message can't be
nil"]);
}];
[self waitForExpectationsWithTimeout:2 handler:nil];
}

7. Singleton
// LoopdManager.h file
+ (instancetype)sharedManager;
// LoopdManager.m file
+ (instancetype)sharedManager {
static dispatch_once_t onceToken;
static LoopdManager *sharedInstance;
dispatch_once(&onceToken, ^{
sharedInstance = [[LoopdManager alloc] init];
});
return sharedInstance;
}

8. Test Singleton Example
- (void)testSharedManager {
LoopdManager *manager1 = [LoopdManager sharedManager];
LoopdManager *manager2 = [LoopdManager sharedManager];
LoopdManager *manager3 = [LoopdManager new];
XCTAssertNotNil(manager1);
XCTAssertNotNil(manager2);
XCTAssertEqual(manager1, manager2);
XCTAssertNotEqual(manager1, manager3);
}

9. OCMock
• mock objects are simulated objects that mimic the
behavior of real objects in controlled ways
- (void)testMock {
id mockUserInfo = OCMClassMock([UserInfo class]);
// fullname should be nil for now
XCTAssertNil([mockUserInfo fullname]);
// make a custom return value
OCMStub([mockUserInfo fullname]).andReturn(@"David");
// fullname should be David now
XCTAssert([[mockUserInfo fullname] isEqualToString:@"David"]);
}

10. OCMock Example (1)
ListViewController has a collection view
find all SomeModel from server when viewDidLoad
// in SomeModel.h file
@interface SomeModel : ModelObject
+ (void)findAllByCurrentUserId:(NSString *)currentUserId
completion:(ArrayResultBlock)completion;
@end

11. OCMock Example (2)
- (void)testCollectionViewCellNumber {
id mockSomeModel = OCMClassMock([SomeModel class]);
OCMStub([mockSomeModel findAllRelationshipsByCurrentUserId:[OCMArg any]
completion:[OCMArg
any]]).andDo(^(NSInvocation *invocation) {
ArrayResultBlock completion;
[invocation getArgument:&completion atIndex: 3];
NSArray *someModels = @[@“1”, @“2”, @“3”, @“4”, @“5”];
completion(someModels, nil);
});
ListViewController *listVC = [ListViewController new];
listVC.view;
NSInteger num = [listVC collectionView:nil numberOfItemsInSection:0];
XCTAssert(num == 5);
XCTAssert(num != 6);
}

12. KIF
• KIF iOS Integration Testing Framework

14. KIF Example
@interface UITests : KIFTestCase
@end
@implementation UITests
- (void)testLoginSteps {
[tester tapViewWithAccessibilityLabel:@"regular_button"];
[tester enterText:@"123@123.com" intoViewWithAccessibilityLabel:@"emailTextField"];
[tester enterText:@"abcdefg" intoViewWithAccessibilityLabel:@"passwordTextField"];
[tester tapViewWithAccessibilityLabel:@“checkmark_button"];
}
@end

15. MVC & MVP

16. MVC
• view can retrieve data
from model directly
• view hosts all the UI
controls
• high coupling

17. MVC & MVP

18. MVP
• MVP is a derivation of the
MVC architectural pattern
• view can’t retrieve data from
model directly
• low coupling

19. MVP's advantage
• easier to unit test, clean
separation of the View and Model
• maintainability of UI increases
due to almost no dependency on
business logic
• Usually view to presenter map
one to one. Complex views may
have multi presenters

20. - (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView
cellForItemAtIndexPath:(NSIndexPath *)indexPath {
UICollectionViewCell *cell = [collectionView
dequeueReusableCellWithReuseIdentifier:@"Cell"
forIndexPath:indexPath];
// config cell
Car *car = self.cars[indexPath.item];
cell.makeLabel.text = car.make;
cell.modelLabel.text = car.model;
cell.yearLabel.text = car.year;
cell.detailLabel.text = car.detail;
return cell;
}

21. - (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView
cellForItemAtIndexPath:(NSIndexPath *)indexPath {
UICollectionViewCell *cell = [collectionView
dequeueReusableCellWithReuseIdentifier:@"Cell"
forIndexPath:indexPath];
// config cell
Car *car = self.cars[indexPath.item];
cell.car = car;
[cell showUI];
return cell;
}

23. Test Cell
- (void)testCollectionViewCellNumber {
id mockSomeModel = OCMClassMock([SomeModel class]);
OCMStub([mockSomeModel findAllRelationshipsByCurrentUserId:[OCMArg any]
completion:[OCMArg
any]]).andDo(^(NSInvocation *invocation) {
ArrayResultBlock completion;
[invocation getArgument:&completion atIndex: 3];
NSArray *someModels = @[mod1, mod2, mod3, mod4, mod5];
completion(someModels, nil);
});
ListViewController *listVC = [ListViewController new];
listVC.view;
NSInteger num = [listVC collectionView:nil numberOfItemsInSection:0];
XCTAssert(num == 5);
XCTAssert(num != 6);
UICollectionViewCell *cell = [contactListVC collectionView:nil
cellForItemAtIndexPath:0];
}

26. Spike Solution

27. Spike Solution
• not sure how to achieve some
requirement.

28. Spike Solution (2)
• A spike solution is dirty and quick.
Code just enough to get the answer
you need.
• Throw it away when you’re done with
it.

29. Spike Solution (3)
• open a new branch
• do some test in the branch
• Throw it away when you’re done with
it

30. TDD with Xcode
• requirement: a helper for add two
integers

31. TDD with Xcode (2)
• create files

32. TDD with Xcode (3)

33. TDD with Xcode (4)
• command+u

34. TDD with Xcode (5)
• verify the function

35. TDD with Xcode (6)
• finish the function then test again

36. how I feel for TDD at
beginning

37. benefits of Testing/TDD
• test => spec
• saves you development time
• saves you development time
• Good unit testing forces good
architecture. In order to make your
code unit-testable, it must be properly
modularized, by writing the unit
testing first various architectural
problems tend to surface earlier

38. The End

39. references
• http://iosunittesting.com
• http://stackoverflow.com/questions/
1053406/why-does-apple-say-iphone-
apps-use-mvc
• http://blog.sanc.idv.tw/2011/09/uimvp-
passive-view.html