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
   

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2. • Project rescue expert.
   • Dev, mentor, public speaker.
   • Consultant at Zenika.
   Anna Filina
   

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3. Behavior:
   does it do what

   the user wants?
   

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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));
   }
   }
   

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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
   

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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)
   

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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"
   

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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
   

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9. --- Expected
   +++ Actual
   @@ @@
   "data": [
   {
   "id": 2,
   - "name": "Product 2",
   + "name": "WRONG DATA",
   "price": 10,
   "quantity": 2
   },
   

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10. More than just

    JSON matching.
    

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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
    

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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
    

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13. Bug in Mobile App
    Items
    GET /api/users/1/cart
    Authorization: Bearer TOKEN_1
    Cart
    

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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
    

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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"
    

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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
    

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17. I need my API
    to go faster.
    How much
    faster?
    It takes 3s.

    Bring it under 0.5
    Got it.
    

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18. Custom Steps
    

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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
    

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20. Given the fixtures file "expired_token.yml" is loaded
    

    Then max 3 queries were executes

    Then query time is under 0.05 seconds
    

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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
    );
    }
    }
    

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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();
    }
    

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23. More than just

    REST APIs.
    

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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
    

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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)
    

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27. Goutte
    Web Server
    Behat
    Behat

    Goutte Driver
    Started before tests
    

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28. But my
    JavaScript!
    

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29. Selenium
    Browser
    Behat
    Behat

    Selenium Driver
    Selenium Server
    Started before tests
    Web Server
    Browser's
    Driver
    

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30. composer require --dev \
    behat/mink-selenium2-driver \

    se/selenium-server-standalone

    

    

    npm install chromedriver

    

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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
    

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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)
    

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34. Browser tests are

    hardest to maintain.
    

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35. • Limit number of browser tests.
    • Test the JS using JS tooling.
    • Focus on critical path (checkout).
    Tips
    

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36. Behat can do

    unit tests, but...
    

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37. • Does the app do what the user wants?
    • Useful for "design by contract".
    • Security, performance, etc.
    • API, HTML & browser.
    Takeaways
    

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38. @afilina | afilina.com | youtube.com/c/AnnaFilina
    

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