Lightning fast tests at Dutch PHP Conference

One of the benefits of having an automated test suite is the feedback given when code is being changed. As the project grows, the test suite becomes slower and slower every day, until it’s so slow it stops being useful. Tests are disabled, skipped and finally removed.

Huge part of the problem lies in getting the testing pyramid wrong and putting to much effort into wrong type of testing.

Learn how to structure your project to benefit from lightning fast tests. Apply the right amount of testing on appropriate levels, and run your tests in seconds, not hours.

Transcript

1. LIGHTNING FAST TESTS Jakub Zalas https://www.flickr.com/photos/captainkimo/7934118876/ @jakub_zalas @jakzal DUTCH PHP CONFERENCE 25th of JUNE 2016 - RAI - AMSTERDAM
2. WHAT MAKES TESTS SLOW? https://www.flickr.com/photos/davemedia/6158362891/
3. Selenium Web server + PHP Symfony WebDriverTest DB API MyCode Controller Service A Service B GoutteTest BrowserKitTest ServiceTest TYPES OF AUTOMATED TESTS ➤ Integration ➤ UI ➤ Service ➤ Acceptance ➤ etc ➤ Unit
4. if ($serviceA->isEnabled()) {
 $serviceB->callFoo();
 } else {
 $serviceB->callBar();
 }
 
 if ($serviceA->has('foo') && $serviceA->has('bar')) {
 $serviceB->callBaz();
 } COUNT EXECUTION PATHS 2 4 2 x 4 = 8
5. EXECUTION PATHS IN AN INTEGRATION TEST MyCode Controller Repository Service A Service B 4 2 5 2 4 x 2 x 5 x 2 = 80
6. EXECUTION PATHS IN AN INTEGRATION TEST MyCode Controller Repository Service A Service B 4 2 2 2 4 x 2 x 5 x 2 = 80 Service C 3 4 x 2 x 2 x 3 x 2 = 96
7. FEEDBACK
8. RELIABILITY
9. SPEED’S NOT THE ONLY ISSUE https://www.flickr.com/photos/hsing/3580898648/ Unit Integration Fast Slow Reliable Brittle Good feedback Poor feedback Grow linearly Grow exponentially Force better design Put pressure off the design Isolated Can simulate user journeys
10. TEST PYRAMID Unit Service UI Succeeding with Agile: Software Development Using Scrum, Mike Cohn
11. INVERTED TEST PYRAMID Unit Service UI
12. TESTING ICE-CREAM CONE Unit Service UI Manual tests http://watirmelon.com/2012/01/31/introducing-the-software-testing-ice-cream-cone/
13. UNIT TESTING https://www.flickr.com/photos/ghozttramp/15390041831/
14. IMPLEMENTING A PRICE CALCULATOR ➤ A small service to calculate a product price in chosen currency ➤ Products are stored in a database ➤ Currency converter is provided as a third party API
15. THE OBVIOUS IMPLEMENTATION PriceCalculator Guzzle Client use Doctrine\ORM\EntityManager;
 use GuzzleHttp\Client;
 
 final class PriceCalculator
 {
 /**
 * @var EntityManager
 */
 private $em;
 
 /**
 * @var Client
 */
 private $guzzle;
 
 public function __construct(EntityManager $em, Client $guzzle)
 {
 $this->em = $em;
 $this->guzzle = $guzzle;
 }
 
 public function price($productUuid, Currency $targetCurrency)
 {
 }
 } Doctrine EntityManager
16. PriceCalculator Guzzle Client public function price($productUuid, Currency $targetCurrency)
 {
 $products = $this->em->getRepository(Product::class);
 $product = $products->findOneByUuid($productUuid);
 
 if (!$product) {
 throw new ProductNotFoundException();
 }
 
 if ($product->isOutOfStock()) {
 throw new OutOfStockException();
 }
 
 if ($product->isPriceInCurrency($targetCurrency)) {
 return $product->getPrice();
 }
 
 $price = $product->getPrice();
 $query = http_build_query([
 'amount' => $price->getAmount(),
 'from_currency' => $price->getCurrencyCode(),
 'to_currency' => $targetCurrency->getCode(),
 ]);
 $response = $this->guzzle->get('/convert?'.$query);
 
 $price = json_decode($response->getBody());
 
 return new Price($price->amount, $targetCurrency);
 } Doctrine EntityManager THE OBVIOUS IMPLEMENTATION
17. // Dummy
 $dummy = $this->prophesize(Foo::class);
 
 // Stub
 $stub = $this->prophesize(Foo::class);
 $stub->something(‘abc’)->willReturn('123');
 
 // Mock
 $mock = $this->prophesize(Foo::class);
 $mock->somethingImportant()->shouldBeCalled(); TEST DOUBLES https://www.flickr.com/photos/loriwright/164567533/
18. UNIT TESTING THE PRICE CALCULATOR PriceCalculator class PriceCalculatorTest extends \PHPUnit_Framework_TestCase
 {
 const UUID = 'foo-u-u-i-d';
 
 public function test_it_converts_price_to_the_target_currency()
 {
 $price = new Price(200, new Currency('GBP'));
 $product = new TestProduct($price);
 $expectedPrice = new Price(277, new Currency('EUR'));
 
 $em = $this->prophesize(EntityManager::class); $productRepository = $this->prophesize(EntityRepository::class); $em->getRepository(Product::class)->willReturn($productRepository);
 $productRepository->findOneByUuid(self::UUID)->willReturn($product);
 
 $guzzle = $this->prophesize(Client::class); $guzzle->get(‘/convert?amount=200&from_currency=GBP&to_currency=EUR’); ->willReturn($this->createResponse(227));
 
 $priceCalculator = new PriceCalculator(
 $productRepository->reveal(),
 $guzzle->reveal()
 );
 $price = $priceCalculator->price(self::UUID, new Currency('EUR'));
 
 $this->assertSame($expectedPrice, $price);
 }
 } Guzzle Client Doctrine EntityManager Don’t mock what you don’t own!
20. Doctrine Manager Guzzle Client DB HTTP Unit tests Integration tests PriceCalculator
21. UNIT TESTING THE PRICE CALCULATOR PriceCalculator Guzzle Client interface ProductRepository
 {
 /**
 * @param string $uuid
 *
 * @return Product
 *
 * @throws ProductNotFoundException if there is no product * for the given uuid
 */
 public function findOneByUuid($uuid);
 } ProductRepository
22. UNIT TESTING THE PRICE CALCULATOR PriceCalculator CurrencyConverter interface CurrencyConverter
 {
 /**
 * @param Price $price
 * @param Currency $targetCurrency
 *
 * @return Currency
 */
 public function convert(Price $price, Currency $targetCurrency);
 } ProductRepository
23. UNIT TESTING THE PRICE CALCULATOR PriceCalculator CurrencyConverter class PriceCalculatorTest extends \PHPUnit_Framework_TestCase
 {
 const UUID = 'foo-u-u-i-d';
 
 public function test_it_converts_price_to_the_target_currency()
 {
 $price = new Price(200, new Currency('GBP'));
 $product = new TestProduct($price);
 $expectedPrice = new Price(277, new Currency('EUR'));
 
 $productRepository = $this->prophesize(ProductRepository::class);
 $productRepository->findOneByUuid(self::UUID)
 ->willReturn($product);
 
 $currencyConverter = $this->prophesize(CurrencyConverter::class);
 $currencyConverter->convert($price, new Currency('EUR'))
 ->willReturn($expectedPrice);
 
 $priceCalculator = new PriceCalculator(
 $productRepository->reveal(),
 $currencyConverter->reveal()
 );
 $price = $priceCalculator->price(self::UUID, new Currency('EUR')); 
 $this->assertSame($expectedPrice, $price);
 }
 } ProductRepository
24. UNIT TESTING THE PRICE CALCULATOR PriceCalculator CurrencyConverter final class PriceCalculator
 {
 /**
 * @var ProductRepository
 */
 private $products;
 
 /**
 * @var CurrencyConverter
 */
 private $converter;
 
 public function __construct(
 ProductRepository $products,
 CurrencyConverter $converter
 ) {
 $this->products = $products;
 $this->converter = $converter;
 }
 
 public function price($productUuid, Currency $targetCurrency)
 {
 $product = $this->products->findOneByUuid($productUuid);
 
 return $this->converter->convert(
 $product->getPrice(),
 $targetCurrency
 );
 }
 } ProductRepository
25. UNIT TESTING THE PRICE CALCULATOR PriceCalculator CurrencyConverter /**
 * @expectedException OutOfStockException
 */
 public function test_it_throws_an_exception_if_product_is_out_of_stock() {
 $product = new OutOfStockProduct(
 new Price(200, new Currency('GBP'))
 );
 
 $productRepository = $this->prophesize(ProductRepository::class);
 $productRepository->findOneByUuid(self::UUID)
 ->willReturn($product);
 
 $currencyConverter = $this->prophesize(CurrencyConverter::class);
 
 $priceCalculator = new PriceCalculator(
 $productRepository->reveal(),
 $currencyConverter->reveal()
 );
 $priceCalculator->price(self::UUID, new Currency('EUR'));
 } ProductRepository
26. UNIT TESTING THE PRICE CALCULATOR PriceCalculator CurrencyConverter final class PriceCalculator
 {
 // ...
 
 public function price($productUuid, Currency $targetCurrency)
 {
 $product = $this->products->findOneByUuid($productUuid);
 
 if ($product->isOutOfStock()) {
 throw new OutOfStockException($product);
 }
 
 return $this->converter->convert(
 $product->getPrice(),
 $targetCurrency
 );
 }
 } ProductRepository
27. Doctrine Manager Guzzle Client DB HTTP Unit tests Integration tests PriceCalculator
28. Doctrine Manager Guzzle Client DB HTTP Unit tests Integration tests PriceCalculator
29. Doctrine Manager Guzzle Client DB HTTP Unit tests Integration tests CurrencyConverter ProductRepository PriceCalculator
30. Doctrine Manager Guzzle Client DB HTTP Unit tests Integration tests CurrencyConverter ProductRepository DoctrineProductRepository GuzzleCurrencyConverter PriceCalculator
31. INTEGRATION TESTING THE REPOSITORY PriceCalculator CurrencyConverter class DoctrineProductRepositoryTest extends \PHPUnit_Framework_TestCase
 {
 protected function setUp()
 {
 // set up the database with fixtures
 }
 
 public function test_it_returns_a_product_by_its_uuid()
 {
 $repository = new DoctrineProductRepository(
 $this->createEntityManager()
 );
 
 $product = $repository->findByUuid('known-u-u-i-d');
 
 $this->assertInstanceOf(Product::class, $product);
 }
 
 /**
 * @expectedException ProductNotFound
 */
 public function test_it_throws_an_exception_if_product_is_not_found( {
 $repository = new DoctrineProductRepository(
 $this->createEntityManager()
 );
 
 $repository->findByUuid('unknown-u-u-i-d');
 }
 } ProductRepository DoctrineProductRepository
32. TWO SIDES OF THE CONTRACT ➤ An interface is a contract ➤ User of the interface makes assumptions about its behaviour in unit tests with test doubles ➤ The implementor of the interface needs to prove it implements the contract properly (test double assumptions are true) ➤ For each expectation in the unit test there should be at least one test to verify that expectation PriceCalculator CurrencyConverter ProductRepository DoctrineProductRepository
33. Doctrine Manager Guzzle Client DB HTTP Unit tests Integration tests CurrencyConverter ProductRepository DoctrineProductRepository GuzzleCurrencyConverter PriceCalculator
34. UNIT TESTING THE CURRENCY CONVERTER PriceCalculator CurrencyConverter interface AcmeApi
 {
 /**
 * @param int $price
 * @param string $fromCurrency
 * @param string $toCurrency
 *
 * @return int
 */
 public function convert($price, $fromCurrency, $toCurrency);
 } ProductRepository DoctrineProductRepository AcmeApiCurrencyConverter GuzzleCurrencyConverter AcmeApi
35. UNIT TESTING THE CURRENCY CONVERTER PriceCalculator CurrencyConverter class AcmeApiCurrencyConverterTest extends \PHPUnit_Framework_TestCase
 {
 public function test_it_returns_the_original_price_if_no_conversion_ {
 $price = new Price(200, new Currency('GBP'));
 $targetCurrency = new Currency('GBP');
 
 $acmeApi = $this->prophesize(AcmeApi::class);
 
 $converter = new AcmeApiCurrencyConverter($acmeApi);
 $actualPrice = $converter->convert($price, $targetCurrency);
 
 $this->assertSame($price, $actualPrice);
 }
 
 public function test_it_calls_the_api_to_convert_the_currency()
 {
 $price = new Price(200, new Currency('GBP'));
 $targetCurrency = new Currency('GBP');
 
 $acmeApi = $this->prophesize(AcmeApi::class);
 $acmeApi->convert(200, 'GBP', 'EUR')->willReturn(277);
 
 $converter = new AcmeApiCurrencyConverter($acmeApi);
 $actualPrice = $converter->convert($price, $targetCurrency);
 
 $this->assertEquals(new Price(277, 'EUR'), $actualPrice);
 }
 } ProductRepository DoctrineProductRepository AcmeApiCurrencyConverter GuzzleCurrencyConverter AcmeApi
36. INTEGRATION TESTING THE CURRENCY CONVERTER PriceCalculator CurrencyConverter use GuzzleHttp\Client;
 
 class GuzzleAcmeApiTest extends \PHPUnit_Framework_TestCase
 {
 public function test_it_converts_the_price()
 {
 $acmeApi = new GuzzleAcmeApi(new Client());
 
 $amount = $acmeApi->convert(200, 'GBP', 'EUR');
 
 $this->assertInternalType('int', $amount);
 }
 } ProductRepository DoctrineProductRepository AcmeApiCurrencyConverter GuzzleCurrencyConverter AcmeApi
37. INTEGRATION TESTING THE CURRENCY CONVERTER PriceCalculator CurrencyConverter use GuzzleHttp\Client;
 
 final class GuzzleAcmeApi implements AcmeApi
 {
 /**
 * @var Client
 */
 private $guzzle;
 
 public function __construct(Client $guzzle)
 {
 $this->guzzle = $guzzle;
 }
 
 public function convert($price, $fromCurrency, $toCurrency)
 {
 $query = http_build_query([
 'amount' => $price,
 'from_currency' => $fromCurrency,
 'to_currency' => $toCurrency,
 ]);
 $response = $this->guzzle->get('/convert?'.$query);
 
 $price = json_decode($response->getBody());
 
 return (int) $price->amount;
 }
 } ProductRepository DoctrineProductRepository AcmeApiCurrencyConverter GuzzleCurrencyConverter AcmeApi
38. Doctrine Manager Guzzle Client DB HTTP Unit tests Integration tests CurrencyConverter ProductRepository DoctrineProductRepository GuzzleCurrencyConverter PriceCalculator
39. Doctrine Manager Guzzle Client DB HTTP Unit tests Integration tests CurrencyConverter ProductRepository DoctrineProductRepository GuzzleCurrencyConverter PriceCalculator
40. Doctrine Manager Guzzle Client DB HTTP Unit tests Integration tests CurrencyConverter ProductRepository DoctrineProductRepository GuzzleCurrencyConverter PriceCalculator AcmeApi
41. Doctrine Manager Guzzle Client DB HTTP Unit tests Integration tests CurrencyConverter ProductRepository DoctrineProductRepository GuzzleCurrencyConverter PriceCalculator AcmeApiCurrencyConverter AcmeApi
42. HEXAGONAL ARCHITECTURE Ports & Adapters https://www.flickr.com/photos/ghozttramp/15390041831/ https://www.flickr.com/photos/25689440@N06/2537853794/
43. PriceCalculator CurrencyConverter ProductRepository AcmeApiCurrencyConverter AcmeApi
44. PriceCalculator CurrencyConverter ProductRepository AcmeApiCurrencyConverter AcmeApi DoctrineProductRepository Doctrine Manager
45. PriceCalculator CurrencyConverter ProductRepository AcmeApiCurrencyConverter AcmeApi DoctrineProductRepository GuzzleCurrencyConverter Doctrine Manager Guzzle Client
46. PriceCalculator CurrencyConverter ProductRepository AcmeApiCurrencyConverter AcmeApi DoctrineProductRepository GuzzleCurrencyConverter Doctrine Manager Guzzle Client InMemoryRepository
47. PriceCalculator CurrencyConverter ProductRepository AcmeApiCurrencyConverter AcmeApi DoctrineProductRepository GuzzleCurrencyConverter Doctrine Manager Guzzle Client InMemoryRepository UI
48. PriceCalculator CurrencyConverter ProductRepository AcmeApiCurrencyConverter AcmeApi DoctrineProductRepository GuzzleCurrencyConverter Doctrine Manager Guzzle Client InMemoryRepository UI PriceCalculatorController Symfony
49. PriceCalculator CurrencyConverter ProductRepository AcmeApiCurrencyConverter AcmeApi DoctrineProductRepository GuzzleCurrencyConverter Doctrine Manager Guzzle Client InMemoryRepository UI PriceCalculatorController Symfony BehatContext Behat
50. @jakub_zalas @jakzal Thank you. Rate my talk, please: https://joind.in/talk/998fb