The last few years have seen a huge adoption of testing practices, and an explosion of different testing tools, in the PHP space. The difficulties come when we have to choose which tools to use, in what combinations, and how to apply them to existing codebases. In this talk we will look at what tools are available, what their strengths are, how to decide which set of tools to use for new or legacy projects, and when to prioritise decoupling and testability over the convenience we get from our frameworks.

1. Building a Test
Pyramid: Symfony
testing strategies
with Ciaran McNulty

2. Before we start:
You must test your
applications!

3. What kind of tests to use?
» Manual testing
» Acceptance testing
» Unit testing
» Integration testing
» End-to-end testing
» Black box / white box

4. What tools to use?
» PHPUnit
» PhpSpec
» Behat
» Codeception
» BrowserKit / Webcrawler

5. Question:
Why can't someone
tell me which one to
use?

6. Answer:
Because there is no
best answer that fits
all cases
You have to find the

7. Testing different layers
Introducing the pyramid
» Defined by Mike Cohn in Succeeding with Agile
» For understanding different layers of testing

9. UI layer tests
» Test the whole application end-to-end
» Sensitive to UI changes
» Aligned with acceptance criteria
» Does not require good code
» Probably slow
e.g. Open a browser, fill in the form and submit it

10. Service layer tests
» Test the application logic by making service calls
» Faster than UI testing
» Aligned with acceptance criteria
» Mostly written in the target language
» Requires high-level services to exist
e.g. Instantiate the Calculator service and get it to add two
numbers

11. Unit level tests
» Test individual classes
» Much faster than service level testing
» Very fine level of detail
» Requires good design

12. Why a pyramid?
» Each layer builds on the one below it
» Lower layers are faster to run
» Higher levels are slower and more brittle
» Have more tests at the bottom than at the top

13. Why do you want
tests?
The answer will affect the type of
tests you write

14. If you want existing
features from
breaking
... write Regression Tests

15. Regression tests
» Check that behaviour hasn't changed
» Easiest to apply at the UI level
» ALL tests become regression tests eventually

16. 'Legacy' code
class BasketController extends Controller
{
public function addAction(Request $request)
{
$productId = $request->attributes->get('product_id');
$basket = $request->getSession()->get('basket_context')->getCurrent();
$products = $basket->getProducts();
$products[] = $productId;
$basket->setProducts($products);
return $this->render('::basket.html.twig', ['basket' => $basket]);
}
}

17. Regression testing with PHPUnit
+ BrowserKit
class PostControllerTest extends WebTestCase
{
public function testShowPost()
{
$client = static::createClient();
$crawler = $client->request('GET', '/products/1234');
$form = $crawler->selectButton('Add to basket')->form();
$client->submit($form, ['id'=>1234]);
$product = $crawler->filter('html:contains("Product: 1234")');
$this->assertCount(1, $product);
}
}

18. Regression testing with
Codeception
$I = new AcceptanceTester($scenario);
$I->amOnPage('/products/1234');
$I->click('Add to basket');
$I->see('Product: 1234');

19. Regression testing with Behat +
MinkExtension
Scenario: Adding a product to the basket
Given I am on "/product/1234"
When I click "Add to Basket"
Then I should see "Product: 1234"

20. Regression testing with Ghost
Inspector

21. When regression testing
» Use a tool that gets you coverage quickly and easily
» Plan to phase out regression tests later
» Lean towards testing end-to-end
» Recognise they will be hard to maintain

22. If you want to match
customer
requirements better
... write Acceptance Tests

23. Acceptance Tests
» Check the system does what the customer wants
» Are aligned with customer language and intention
» Write them in English (or another language) first
» Can be tested at the UI or Service level

24. Start with an
example-led
conversation
... before you start working on it
... but not too long before

25. » "What should the system do when X happens?"
» "Does Y always happen when X?"
» "What assumptions Z are causing Y to be the outcome?"
» "Given Z when X then Y"
» "What other things aside from Y might happen?"
» "What if...?"

26. Write the examples
out in business-
readable tests
Try and make the code look like
the natural conversation you had

27. Easiest to test through
the User Interface

28. UI Acceptance testing with
PHPUnit + BrowserKit
class PostControllerTest extends WebTestCase
{
public function testAddingProductToTheBasket()
{
$this->addProductToBasket(1234);
$this->productShouldBeShownInBasket(1234);
}
private function addProductToBasket($productId)
{
//... browser automation code
}
private function productShouldBeShownInBasket($productId)
{
//... browser automation code
}
}

29. UI Acceptance testing with
Codeception
$I = new AcceptanceTester($scenario);
$I->amGoingTo('Add a product to the basket');
$I->amOnPage('/products/1234');
$I->click('Add to basket');
$I->expectTo('see the product in the basket');
$I->see('Product: 1234');

30. UI Acceptance testing with Behat
+ MinkExtension
Scenario: Adding a product to the basket
When I add product 1234 to the basket
Then I should see product 1234 in the basket

31. UI Acceptance testing with Behat
+ MinkExtension
/**
* @When I add product :productId to the basket
*/
public function iAddProduct($productId)
{
$this->visitUrl('/product/' . $productId);
$this->getSession()->clickButton('Add to Basket');
}
/**
* @Then I should see product :productId in the basket
*/
public function iShouldSeeProduct($productId)
{
$this->assertSession()->elementContains('css', '#basket', 'Product: ' . $productId);
}

32. Acceptance testing
through the UI is slow
and brittle
To test at the service layer, we
need to introduce services

33. 'Legacy' code
class BasketController extends Controller
{
public function addAction(Request $request)
{
$productId = $request->attributes->get('product_id');
$basket = $request->getSession()->get('basket_context')->getCurrent();
$products = $basket->getProducts();
$products[] = $productId;
$basket->setProducts($products);
return $this->render('::basket.html.twig', ['basket' => $basket]);
}
}

34. 'Service-oriented' code
class BasketController extends Controller
{
public function addAction(Request $request)
{
$basket = $this->get('basket_context')->getCurrent();
$productId = $request->attributes->get('product_id');
$basket->addProduct($productId);
return $this->render('::basket.html.twig', ['basket' => $basket]);
}
}

35. A very small change
but now the business logic is out of
the controller

36. Service layer Acceptance testing
with PHPUnit
class PostControllerTest extends PHPUnit_Framework_TestCase
{
public function testAddingProductToTheBasket()
{
$basket = new Basket(new BasketArrayStorage());
$basket->addProduct(1234);
$this->assertContains(1234, $basket->getProducts());
}
}

37. Service layer acceptance testing
with Behat + MinkExtension
Scenario: Adding a product to the basket
When I add product 1234 to the basket
Then I should see product 1234 in the basket

38. Service layer acceptance testing
with Behat
/**
* @When I add product :productId to the basket
*/
public function iAddProduct($productId)
{
$this->basket = new Basket(new BasketArrayStorage());
$this->basket->addProduct($productId);
}
/**
* @Then I should see product :productId in the basket
*/
public function iShouldSeeProduct($productId)
{
assert(in_array($productId, $this->basket->getProducts());
}

39. When all of the
acceptance tests are
running against the
Service layer
... how many also need to be run
through the UI?

40. Symfony is a controller for your
app

41. If you test everything
through services
... you only need
enough UI tests to be
sure the UI is

42. Multiple Behat suites
Scenario: Adding a product to the basket
When I add product 1234 to the basket
Then I should see product 1234 in the basket
Scenario: Adding a product that is already there
Given I have already added product 1234 to the basket
When I add product 1234 to the basket
Then I should see 2 instances of product 1234 in the basket
@ui
Scenario: Adding two products to my basket
Given I have already added product 4567 to the basket
When I add product 1234 to the basket
Then I should see product 4567 in the basket
And I should also see product 1234 in the basket

43. Multiple Behat suites
default:
suites:
ui:
contexts: [ UiContext ]
filters: { tags: @ui }
service:
contexts: [ ServiceContext ]

44. If you want the design
of your code to be
better
... write Unit Tests

45. Unit Tests
» Check that a class does what you expect
» Use a tool that makes it easy to test classes in isolation
» Move towards writing them first
» Unit tests force you to have good design
» Probably too small to reflect acceptance criteria

46. Unit tests are too granular
Customer: "The engine needs to produce 500bhp"
Engineer: "What should the diameter of the main drive shaft
be?"

47. Unit testing in PHPUnit
class BasketTest extends PHPUnit_Framework_Testcase
{
public function testGetsProductsFromStorage()
{
$storage = $this->getMock('BasketStorage');
$storage->expect($this->once())
->method('persistProducts')
->with([1234]);
$basket = new Basket($storage);
$basket->addProduct(1234);
}
}

48. Unit testing in PhpSpec
class BasketSpec extends ObjectBehavior
{
function it_gets_products_from_storage(BasketStorage $storage)
{
$this->beConstructedWith($storage);
$this->addProduct(1234);
$storage->persistProducts([1234])->shouldHaveBeenCalled([1234]);
}
}

49. Unit test
... code that is responsible for
business logic
... not code that interacts with
infrastructure including Symfony

50. You can unit test
interactions with
Symfony (e.g.
controllers)
You shouldn't need to if you have
acceptance tests

51. Coupled architecture

52. Unit testing third party
dependencies
class FileHandlerSpec extends ObjectBehaviour
{
public function it_uploads_data_to_the_cloud_when_valid(
CloudApi $client, FileValidator $validator, File $file
)
{
$this->beConstructedWith($client, $validator);
$validator->validate($file)->willReturn(true);
$client->startUpload()->shouldBeCalled();
$client->uploadData(Argument::any())->shouldBeCalled();
$client->uploadSuccessful()->willReturn(true);
$this->process($file)->shouldReturn(true);
}
}

53. Coupled architecture

54. Layered architecture

55. Testing layered architecture

56. class FileHandlerSpec extends ObjectBehaviour
{
public function it_uploads_data_to_the_cloud_when_valid(
FileStore $filestore, FileValidator $validator, File $file
)
{
$this->beConstructedWith($filestore, $validator);
$validator->validate($file)->willReturn(true);
$this->process($file);
$filestore->store($file)->shouldHaveBeenCalled();
}
}

57. Testing layered architecture

58. class CloudFilestoreTest extends PHPUnit_Framework_TestCase
{
function testItStoresFiles()
{
$testCredentials = …
$file = new File(…);
$apiClient = new CloudApi($testCredentials);
$filestore = new CloudFileStore($apiClient);
$filestore->store($file);
$this->assertTrue($apiClient->fileExists(…));
}
}

59. Testing layered architecture

60. To build your
pyramid...

61. Have isolated unit-
tested objects
representing your core
business logic
10,000s of tests running in <10ms
each

62. Have acceptance tests
at the service level
1,000s of tests running in <100ms
each

63. Have the bare
minimum of
acceptance tests at the
UI level
10s of tests running in <10s each

64. Thank You!
Any questions?
https://joind.in/talk/view/14972
@ciaranmcnulty
ciaran@sessiondigital.co.uk