Automated Testing (Cocoaheads Montréal - 11/02/2014) 

Who ? ▸ Romain Pouclet ▸ iOS developer ▸ Building stuff at TechSolCom 

How many developer in the room? 

How many of you have already written a unit test case? 

How many of you have already written a functional test case ? 

The streching session is over, you can go back to your beer 

Reasons to test 

Reasons to test ▸ Make sure everything work as expected ▸ Avoid regression ▸ Natural documentation ▸ Ease maintenance and refactoring ▸ Sleep better at night 

Reasons not to test 

Reasons not to test Prototyping Deadlines Testing is hard I don't need them, I know what I'm doing 

Reasons not to test Prototyping Deadlines Testing is hard I don't need them, I know what I'm doing 

Reasons not to test Prototyping Deadlines Testing is hard I don't need them, I know what I'm doing 

Reasons not to test Prototyping Deadlines Testing is hard I don't need them, I know what I'm doing 

Example Parsing some XML 

Example : XML parsing ▸ Augmented reality application using Vuforia ▸ Metadata stored here (Vuforia) and there (Client database) 

Example : XML parsing 1 Harry Potter and the goblet of fire 2 Harry Potter and the Deathly Hallows 

Dead simple XML parsing PCSGetBookDetailsParserDelegate *parsingDelegate = [[PCSGetBookDetailsParserDelegate alloc] init]; NSXMLParser *parser = [[NSXMLParser alloc] initWithContentsOfURL: url]; parser.delegate = parsingDelegate; BOOL result = [parser parse]; PCSBook *book = parsingDelegate.book; 

The developer (not me, another nice guy) didn't write any test for this 

"There are too much metadata on Vuforia, please only use item and image data and fetch the rest from the backoffice" 

Sure! [[PCSGetBookDetailsParserDelegate alloc] initWithWhiteList: @[@"imagedata", @"item"]]; 

Guess what? 

There is a bug in the application when the user search for a book on a tuesday — A (nice) client 

Achievement unlocked ! humility 

Write a failing test case - (void)testItemIdIsNotOverridenByRecommandationItemId { NSURL *url = [[NSBundle bundleForClass: [self class]] URLForResource: @"342279" withExtension: @"xml"]; NSAssert(url, @"URL for sample payload should be properly loadded"); PCSGetBookDetailsParserDelegate *parsingDelegate = [[PCSGetBookDetailsParserDelegate alloc] initWithWhiteList: @[@"imagedata", @"item"]]; NSXMLParser *parser = [[NSXMLParser alloc] initWithContentsOfURL: url]; parser.delegate = parsingDelegate; BOOL result = [parser parse]; NSAssert(result, @"Payload shoud be successfully parsed."); PCSBook *book = parsingDelegate.book; XCTAssertEqualObjects(@"342279", book.item); } 

Failing test case : load data you know NSURL *url = [[NSBundle bundleForClass: [self class]] URLForResource: @"342279" withExtension: @"xml"]; NSAssert(url, @"URL for sample payload should be properly loadded"); 

Failing test case : do the actual parsing PCSGetBookDetailsParserDelegate *parsingDelegate = [[PCSGetBookDetailsParserDelegate alloc] initWithWhiteList: @[@"imagedata", @"item"]]; NSXMLParser *parser = [[NSXMLParser alloc] initWithContentsOfURL: url]; parser.delegate = parsingDelegate; BOOL result = [parser parse]; NSAssert(result, @"Payload shoud be successfully parsed."); 

Failing test case : add your assertions PCSBook *book = parsingDelegate.book; XCTAssertEqualObjects(@"342279", book.item); 

Run your code ⌘ + U or xcodebuild test 

Or... Xctool (facebook) $ brew install xctool $ xctool -project XMLParsing.xcodeproj -scheme XMLParsing test 

Or... Xcodebuild and XCPretty $ gem install xcpretty $ xcodebuild test | xcpretty 

The secret of happiness* 1. Find a bug 2. Write a (failing) test case 3. Fix the bug 4. Repeat (* not really) 

Unit testing Test the smallest part of an application (= unit) 

A good test suite is... 

Easy to read - (void)testSomethingShouldHappenThisWay { Stuff *someStuff = [[Stuff alloc] init]; XCTAssertEqualObjects(@"Expected result", [someStuff performSomeAction], @"The action should do something") } 

Fast to run 

Separation of concern Don't duplicate your checks : higher-level tests assume that lower-level code works. 

Avoid singletons @implementation PCSSuperImportantObject - (instancetype)init { self = [super init]; if (self) { self.connection = [PCSTwitterConnection sharedConnection]; } return self; } @end 

Use dependency injection! @implementation PCSSuperImportantObject - (instancetype)initWithConnection:(PCSTwitterConnection *)connection { self = [super init]; if (self) { self.connection = connection; } return self; } @end 

... So you can mock them later id connection = [OCMockObject mockForClass: [PCSTwitterConnection class]]; [[[connection stub] andReturn: @367] followerCountsForUsername: [OCMArg any]]; NSLog(@"Followers = %@", [connection followerCountsForUsername: @"CocoaheadsMTL"]); 

Don't test everything HSWizard *harry = [[HSWizard alloc] init]; harry.house = @"Gryffindor"; XCTAssertEqualsObject(@"Gryffindor", harry.house); 

But wait there's more ! 

Acceptance testing using KIF - (void)testSuccessfulLogin { [tester enterText: @"https://confluence-url.com" intoViewWithAccessibilityLabel: @"Confluence URL"]; [tester enterText: @"apple.review" intoViewWithAccessibilityLabel: @"Confluence username"]; [tester enterText: @"applereview" intoViewWithAccessibilityLabel: @"Confluence password"]; [tester tapViewWithAccessibilityLabel: @"Log In"]; // Verify that the login succeeded [tester waitForTappableViewWithAccessibilityLabel: @"Spaces list"]; [tester tapRowInTableViewWithAccessibilityLabel: @"Spaces list" atIndexPath: [NSIndexPath indexPathForRow: 0 inSection: 0]]; [tester waitForTappableViewWithAccessibilityLabel: @"Main menu"]; } 

Acceptance testing using Frank Feature: As a user I want to be able to see the weather of a region So I can see if I need to bring flip flops or a snow shovel Scenario: I need to be able to select a city Given I launch the app And I touch "Select weather city" And I wait to see "Alma" And I touch "Alma" Then I should see "Alma" $ cucumber features/weather.feature 

It is not about testing everything It is about raising your level of confidence in your code 

Thank you! (Questions ?)