Behat: Why and How?

Unit tests are great, but on their own, they don't tell you whether your application behaves as expected. Can a user access someone else's records? Do your translations work correctly based on request headers? Learn how to write relevant Behat tests, how to set everything up and how a backend and a frontend can be developed in parallel.

Transcript

1. @afilina Behat: Why and How? ConFoo | March 7, 2018 | Montreal
2. • Project rescue expert. • Dev, mentor, public speaker. • Consultant at Zenika. Anna Filina
3. Behavior: does it do what
 the user wants?
4. class CartTest extends TestCase { public function testGetTax() { $mock = $this->getMock('Cart',['getTaxRate']); $mock->expects($this->once()) ->method('getTaxRate') ->will($this->returnValue(0.15)); $this->assertEquals(15, $mock->getTax(100)); } }
5. Feature: Cart Items In order to let customers purchase products As a developer I need to add items to the shopping cart Background: Given the fixtures file "cart_items.yml" is loaded Scenario: List own cart items Given I send a "GET" request to "/api/users/1/cart" Then the response status code should be 200 And the JSON node "data" should have 2 elements
6. $ vendor/bin/behat Feature: Cart Items In order to let customers purchase products As a developer I need to add items to the shopping cart Background: Given the fixtures file "cart_items.yml" is loaded
 Scenario: List own cart items Given I send a "GET" request to "/api/users/1/cart" Then the response status code should be 200 And the JSON node "data" should have 2 elements 1 scenario (1 passed) 4 steps (4 passed) 0m0.31s (29.05Mb)
7. Feature: Cart Items In order to let customers purchase products As a developer I need to add items to the shopping cart Background: Given the fixtures file "cart_items.yml" is loaded Scenario: List own cart items Given I send a "GET" request to "/api/users/1/cart" Then the response status code should be 200 And the JSON should be equal to file "users_1_cart.json"
8. /api/users/1/cart { "data": [ { "id": 2, "name": "Product 2", "price": 10, "quantity": 2 }, { "id": 1, "name": "Product 1", "price": 10, "quantity": 2 } ] } Backend dev Frontend dev
9. --- Expected +++ Actual @@ @@ "data": [ { "id": 2, - "name": "Product 2", + "name": "WRONG DATA", "price": 10, "quantity": 2 },
10. More than just
 JSON matching.
11. Scenario: Unauthenticated list Given I send a "GET" request to "/api/users/1/cart" Then the response status code should be 401 Scenario: List own cart items Given I add "Authorization" header equal to "Bearer TOKEN_1" And I send a "GET" request to "/api/users/1/cart" Then the response status code should be 200
12. Scenario: List another user's cart items Given I add "Authorization" header equal to "Bearer TOKEN_1" And I send a "GET" request to "/api/users/2/cart" Then the response status code should be 403
13. Bug in Mobile App Items GET /api/users/1/cart Authorization: Bearer TOKEN_1 Cart
14. Background: Given the fixtures file "expired_token.yml" is loaded Scenario: Expired token Given I add "Authorization" header equal to "Bearer TOKEN_1" And I send a "GET" request to "/api/users/1/cart" Then the response status code should be 401
15. Scenario: List cart items in French Given I add "Accept-Language" header equal to "fr-CA,en;q=0.9"
 And I send a "GET" request to "/api/users/1/cart" Then the response status code should be 200 And the JSON should be equal to file "users_1_cart_fr.json"
16. Scenario: List own cart items Given I add "Authorization" header equal to "Bearer TOKEN_1" And I send a "GET" request to "/api/users/1/cart" Then the response status code should be 200 And max 3 queries were executes And query time is under 0.05 seconds
17. I need my API to go faster. How much faster? It takes 3s.
 Bring it under 0.5 Got it.
18. Custom Steps
19. Given I add "Authorization" header equal to "Bearer TOKEN_1"
 Given I send a "GET" request to "/api/users/1/cart"
 Then the response status code should be 200
20. Given the fixtures file "expired_token.yml" is loaded 
 Then max 3 queries were executes
 Then query time is under 0.05 seconds
21. class JsonContext extends \Behatch\Context\JsonContext { /** * @Then the JSON should be equal to file :filename */ public function theJsonShouldBeEqualToFile(string $filename):void { $actualJson = json_encode( $this->getJson()->getContent(), JSON_PRETTY_PRINT ); $expectedJson = file_get_contents( __DIR__ . '/../../json/'.$filename ); PHPUnit\Framework\Assert::assertJsonStringEqualsJsonString( $expectedJson, $actualJson ); } }
22. /** * @Given the fixtures file :filename is loaded */ public function loadYamlFixtures(string $filename):void { $loader = new \Nelmio\Alice\Loader\NativeLoader(); $objectSet = $loader->loadFile(__DIR__.'/../../fixtures/'.$filename); foreach ($objectSet->getObjects() as $object) { $className = get_class($object); $this->em->persist($object); } $this->em->flush(); }
23. More than just
 REST APIs.
25. Feature: Product search Background: Given the fixtures file "products.yml" is loaded Scenario: Search existing products Given I am on "/products/Elder+Scrolls" Then the response status code should be 200 And I should see 5 "div.product" elements
26. Feature: Product search Background: Given the fixtures file "products.yml" is loaded Scenario: Search existing products Given I am on "/products/Elder+Scrolls" Then the response status code should be 200 And I should see 5 "div.product" elements 1 scenario (1 passed) 4 steps (4 passed) 0m0.28s (29.15Mb)
27. Goutte Web Server Behat Behat
 Goutte Driver Started before tests
28. But my JavaScript!
29. Selenium Browser Behat Behat
 Selenium Driver Selenium Server Started before tests Web Server Browser's Driver
30. composer require --dev \ behat/mink-selenium2-driver \
 se/selenium-server-standalone
 
 
 npm install chromedriver

32. @javascript Scenario: Filter products Given I am on "/products" When I fill in "search" with "path" Then I should see 1 "div.product.visible" element No :visible pseudoclass
33. Feature: Product search Background: Given the fixtures file "products.yml" is loaded @javascript Scenario: Filter products Given I am on "/products" When I fill in "search" with "path" Then I should see 1 "div.product.visible" element 1 scenario (1 passed) 4 steps (4 passed) 0m2.27s (20.53Mb)
34. Browser tests are
 hardest to maintain.
35. • Limit number of browser tests. • Test the JS using JS tooling. • Focus on critical path (checkout). Tips
36. Behat can do
 unit tests, but...
37. • Does the app do what the user wants? • Useful for "design by contract". • Security, performance, etc. • API, HTML & browser. Takeaways
38. @afilina | afilina.com | youtube.com/c/AnnaFilina