Behat BDD Skill

Core Patterns

Feature File (features/login.feature)

Feature: User Login
  As a user I want to log in

  Scenario: Successful login
    Given I am on "/login"
    When I fill in "email" with "user@test.com"
    And I fill in "password" with "password123"
    And I press "Login"
    Then I should see "Dashboard"
    And I should be on "/dashboard"

  Scenario: Invalid credentials
    Given I am on "/login"
    When I fill in "email" with "wrong@test.com"
    And I fill in "password" with "wrong"
    And I press "Login"
    Then I should see "Invalid credentials"

Custom Context (features/bootstrap/LoginContext.php)

<?php
use Behat\MinkExtension\Context\MinkContext;
use Behat\Behat\Context\Context;

class LoginContext extends MinkContext implements Context
{
    /**
     * @When I login as :email with password :password
     */
    public function iLoginAs(string $email, string $password): void
    {
        $this->visit('/login');
        $this->fillField('email', $email);
        $this->fillField('password', $password);
        $this->pressButton('Login');
    }

    /**
     * @Then I should see the dashboard
     */
    public function iShouldSeeTheDashboard(): void
    {
        $this->assertSession()->addressEquals('/dashboard');
        $this->assertSession()->pageTextContains('Welcome');
    }

    /**
     * @Then the response time should be under :ms milliseconds
     */
    public function responseUnder(int $ms): void
    {
        // Custom performance assertion
    }
}

Built-in MinkContext Steps

# Navigation
Given I am on "/path"
When I go to "/path"
When I reload the page

# Forms
When I fill in "field" with "value"
When I select "option" from "select"
When I check "checkbox"
When I uncheck "checkbox"
When I press "button"
When I attach the file "path" to "field"

# Assertions
Then I should see "text"
Then I should not see "text"
Then I should be on "/path"
Then the response status code should be 200
Then the "field" field should contain "value"
Then I should see an "css-selector" element
Then print current URL

behat.yml

default:
  suites:
    default:
      contexts:
        - LoginContext
        - Behat\MinkExtension\Context\MinkContext
  extensions:
    Behat\MinkExtension:
      base_url: 'http://localhost:3000'
      sessions:
        default:
          selenium2:
            browser: chrome
            wd_host: 'http://localhost:4444/wd/hub'

Tags

./vendor/bin/behat --tags=@smoke
./vendor/bin/behat --tags="@smoke&&~@slow"

Setup: composer require --dev behat/behat behat/mink-extension behat/mink-selenium2-driver

Init: ./vendor/bin/behat --init

Cloud Execution on TestMu AI

Set environment variables: LT_USERNAME, LT_ACCESS_KEY

# behat.yml
default:
  extensions:
    Behat\MinkExtension:
      base_url: 'https://your-app.com'
      selenium2:
        wd_host: 'https://hub.lambdatest.com/wd/hub'
        capabilities:
          browser: 'chrome'
          extra_capabilities:
            'LT:Options':
              user: '%env(LT_USERNAME)%'
              accessKey: '%env(LT_ACCESS_KEY)%'
              build: 'Behat Build'
              name: 'Behat Test'
              platformName: 'Windows 11'
              video: true
              console: true
              network: true

Run: ./vendor/bin/behat or ./vendor/bin/behat features/login.feature

Deep Patterns

See reference/playbook.md for production-grade patterns:

Section	What You Get
§1 Project Setup	behat.yml with suites, Mink extension, profiles, project structure
§2 Feature Files	Gherkin with Scenario Outline, Background, TableNode data
§3 Context Classes	Step definitions, dependency injection, API context, assertions
§4 Hooks	BeforeSuite/Scenario/Step, screenshot on failure, transaction rollback
§5 Page Objects	Page Object pattern with elements map, reusable components
§6 LambdaTest Integration	Remote Selenium config, cloud browser profiles
§7 Custom Formatters	HTML report formatter, result collection
§8 CI/CD Integration	GitHub Actions with MySQL, Selenium, JUnit reports
§9 Debugging Table	12 common problems with causes and fixes
§10 Best Practices	14-item BDD testing checklist