Variadic Extension Laravel Package

Getting Started

Minimal Setup

1. Installation:

   composer require friends-of-behat/variadic-extension --dev
   

   Add to behat.yml:

   extensions:
       FriendsOfBehat\VariadicExtension: ~
   

2. First Use Case: Replace repetitive step definitions like:

   /**
    * @When I have :count items
    */
   public function iHaveOneItem() { ... }
   
   /**
    * @When I have :count items
    */
   public function iHaveTwoItems($count) { ... }
   

   With a single variadic method:

   /**
    * @When I have :count items
    */
   public function iHaveItems($count, ...$additionalArgs) { ... }
   

Implementation Patterns

Core Workflow

1. Step Definition Consolidation: Use variadic arguments (...$args) to handle dynamic argument counts:

   /**
    * @When I perform action :action on :target with :options
    */
   public function performAction($action, $target, ...$options) {
       if (empty($options)) {
           // Handle minimal args
       } else {
           // Process additional args
       }
   }
   

2. Integration with Laravel:

   • Service Container: Inject dependencies via Laravel's DI:

     public function __construct(private UserRepository $users) {}
     

   • Context Initialization: Use Laravel's app() helper in contexts:

     $this->users = app(UserRepository::class);
     

3. Type Safety: Combine with PHP 7.4+ typed properties or return types:

   public function calculateTotal(float ...$prices): float { ... }
   

Advanced Patterns

• Argument Validation:

  public function processItems(...$items) {
      if (count($items) < 1) {
          throw new \InvalidArgumentException("At least one item required");
      }
  }
  

• Default Values:

  public function configure($name, ...$config) {
      $defaults = ['timeout' => 30];
      $merged = array_merge($defaults, $config);
  }
  

Gotchas and Tips

Common Pitfalls

1. Argument Order Sensitivity: Variadic args must be last in the method signature. This will fail:

   // ❌ Wrong
   public function example(...$args, $required) { ... }
   

2. Behat Step Matching:

   • Overly generic step definitions may cause ambiguity. Prefix with context:

     @user When I have :count items
     

   • Use @Given/@When/@Then consistently to avoid conflicts.

3. Performance:

   • Avoid complex logic in step definitions. Offload to services:

     $this->userService->process(...$args);
     

Debugging Tips

• Enable Verbose Output:

  behat --verbose
  

  Reveals argument parsing details.

• Check Step Registry:

  behat --dry-run
  

  Validates step definitions before execution.

Extension Points

1. Custom Argument Parsers: Extend FriendsOfBehat\VariadicExtension\ArgumentParser for domain-specific types.

2. Laravel-Specific:

   • Service Binding: Bind Behat contexts to Laravel's container:

     $this->app->bind(FeatureContext::class, function () {
         return new FeatureContext(app(UserRepository::class));
     });
     

   • Environment Awareness: Use Laravel's config in contexts:

     $this->app['config']['behat.timeout'];
     

3. Testing:

   • Mock variadic args in PHPUnit:

     $this->context->processItems(...['item1', 'item2']);