"Extract testable code” & ”Test UI without the simulator”. Small is the beauty!

1. Testing and ViewControllers
"Extract testable code”
&
”Test UI without the simulator”.
Small is the beauty!

2. • What did I do?
• Why / When / Dangers unit test
• A way to make viewControllers testable
• Make tests visible

3. What did I do
• TDD at Philips, small and big projects
• Lots of legacy code refactoring
• App that could have benefitted from testing

4. Unit testing
Integration testing
Webservice
Local device test
External web
service
VC’s Mock web service Views
UI Automation (Calabash)
Helped Developers
Helped ?

5. Legacy code
Legacy class
Sprout Class -> Unit tests
Unit test killers:
• Object should not set there own properties.
• Reach out to a database
• Many dependencies, no default working state on its own

6. Legacy code
Object should not set there own properties.
class ExampleVC: UIViewController {
let userDefaults = NSUserDefaults.standardUserDefaults()
}
class ExampleVC: UIViewController {
var userDefaults : NSUserDefaults?
override func viewDidLoad() {
super.viewDidLoad()
userDefaults = NSUserDefaults.standardUserDefaults()
}
}

7. Legacy code
Object should not set there own properties.
class ExampleVC: UIViewController {
lazy var userDefaults : NSUserDefaults = {
NSUserDefaults.standardUserDefaults()
}()
}

9. Why
Tests written for code coverage
are a waste of time
Write them to write better code or stop writing tests!

10. When
Data
Manipulation
Draw view
What value should I use for
this IndexPath?
I need a list but I have an
object with properties
ViewController
Different states
Do not test animations wait
for the result
Only visible for a very peculiar
state

11. What value should I use for
this IndexPath?
Data
Manipulation
override func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("Cell", forIndexPath: indexPath) as TableViewCell
cell.label.text = self.datasource.item(indexPath)
return cell
}
func testThenHasMessageAndDescription() {
let resultMessage = tableDatasource.item(NSIndexPath(forItem: 0, inSection: 0))
let resultDescription = tableDatasource.item(NSIndexPath(forItem: 1, inSection: 0))
XCTAssertEqual(resultMessage!, “Message”)
XCTAssertEqual(resultDescription!, “Description”)
}

12. Data
Manipulation
I need a list but I have an
object with properties
let fakeResponse = ["message" : "bla", "description" : "bla some more"]
self.mappedArray = [fakeResponse["message"]!, fakeResponse["description"]!]
func item(indexPath: NSIndexPath) -> (String?){
if indexPath.item < mappedArray?.count{
return mappedArray![indexPath.item]
}else{
return nil
}
}

13. Draw view
Different states

14. Do not test animations wait
for the result
Draw view
- (void)testThenShowInPlaceError
{
XCTestExpectation *exp = [self expectationWithDescription:@"Wait for error view"];
self.viewController.viewControllerDatasource.respondWithError = YES;
[self.viewController.viewControllerDatasource reloadDataWithDataCompletion:nil
failure:nil animationCompletion:^(BOOL success) {
FBSnapshotVerifyView(self.viewController.view, @"");
[exp fulfill];
}];
NSTimeInterval animationTime = kAsyncViewsAnimationDuration;
[self waitForExpectationsWithTimeout:animationTime + 2 handler:nil];
}

15. Only visible for a very peculiar
state
Draw view
- (void)testThenOfferCancel
{
id vc = OCMPartialMock([[UIStoryboard storyboardWithName:@"Main" bundle:nil]
instantiateViewControllerWithIdentifier:@"ViewController"]);
//We only use a stub here to have faster test cycles
OCMStub([vc async_timeOutDelay]).andReturn(@1);
XCTestExpectation *exp = [self expectationWithDescription:@"Wait for cancel"];
[self offerCancelOnViewController:vc
exp: exp
test:^(XCTestExpectation *exp) {
FBSnapshotVerifyView(((UIViewController *) vc).view, @"");
[vc stopMocking];
[exp fulfill];
}];
}

16. Danger
Don’t fall in love with your tests

17. Make VC’s Testable
Data
Manipulation
Draw view
ViewController
SharedAsyncDatasource UIViewController+Async

21. Demo
https://github.com/doozMen/SharedAsyncViewController

22. Make Tests visible
Tests are just as important as application
code. Why not put them together?
Jon Reid

23. Inspiration
• http://qualitycoding.org/xcode-unit-testing/
• http://iosunittesting.com
• https://github.com/Inferis/IIAsyncViewController
• “Working Effectively with Legacy Code “
Michael Feathers