Symfony Mocker Container Laravel Package

Getting Started

Minimal Setup

1. Installation:

   composer require polishsymfonycommunity/symfony-mocker-container
   

   Add the package to your composer.json under require (as shown in the README).

2. Configure Kernel: Override getContainerBaseClass() in AppKernel.php (or Kernel.php in Symfony 4+):

   protected function getContainerBaseClass()
   {
       if ('test' === $this->getEnvironment()) {
           return \PSS\SymfonyMockerContainer\DependencyInjection\MockerContainer::class;
       }
       return parent::getContainerBaseClass();
   }
   

   Clear cache:

   php bin/console cache:clear
   

3. First Use Case: In a functional test (or Behat scenario), mock a service:

   $mock = $this->getMockBuilder('App\Service\MyService')
       ->disableOriginalConstructor()
       ->getMock();
   
   $this->container->set('app.my_service', $mock);
   

Implementation Patterns

Workflows

1. Functional Tests:

   • Use MockerContainer to replace real services with mocks/stubs.
   • Example: Mocking a database service to return canned responses:

     $mockDb = $this->getMockBuilder('Doctrine\DBAL\Connection')
         ->disableOriginalConstructor()
         ->getMock();
     
     $mockDb->method('fetchAll')
         ->willReturn([['id' => 1, 'name' => 'Test']]);
     
     $this->container->set('database_connection', $mockDb);
     

2. Behat Integration:

   • Combine with Symfony2MockerExtension for scenario-level mocking.
   • Example in a Behat context:

     use Behat\MinkExtension\Context\MinkContext;
     use PSS\SymfonyMockerExtension\Context\MockerContext;
     
     class FeatureContext extends MinkContext implements MockerContext {
         public function mockService($serviceId, $mockClass) {
             $mock = $this->getMockBuilder($mockClass)
                 ->disableOriginalConstructor()
                 ->getMock();
             $this->container->set($serviceId, $mock);
         }
     }
     

3. Partial Mocking:

   • Mock only specific methods while keeping others real:

     $partialMock = $this->getMockBuilder('App\Service\Logger')
         ->setMethods(['log'])
         ->getMock();
     
     $partialMock->expects($this->once())
         ->method('log')
         ->with('Test message');
     
     $this->container->set('app.logger', $partialMock);
     

Integration Tips

• Avoid in Unit Tests: This package is functional-test-only. Use PHPUnit's native mocking for unit tests.
• BrowserKit Limitation: Only works with BrowserKitDriver (Symfony functional tests/Behat). HTTP-based drivers (e.g., Goutte) cannot use this.
• Service Aliases: Mock aliases by resolving the target service first:

  $realService = $this->container->get('app.real_service');
  $mock = $this->getMockBuilder(get_class($realService))->getMock();
  $this->container->set('app.alias', $mock);
  

Gotchas and Tips

Pitfalls

1. Cache Dependency:

   • Forgetting to clear the cache after changing AppKernel.php will cause the mocker container to not activate.
   • Always run:

     php bin/console cache:clear
     

2. Environment Mismatch:

   • The mocker only activates in the test environment. Running tests in dev or prod will ignore the override.

3. Non-Test Drivers:

   • Attempting to mock services with Goutte, Selenium2Driver, or other HTTP-based drivers will fail silently. The mocker only works with BrowserKitDriver.

4. Lazy Services:

   • Services defined as lazy (lazy: true in YAML/XML) may not be mockable directly. Resolve them first:

     $this->container->get('app.lazy_service'); // Force initialization
     $mock = $this->getMockBuilder(get_class($service))->getMock();
     $this->container->set('app.lazy_service', $mock);
     

5. Constructor Injection:

   • If a service has constructor arguments, mocking may fail unless you:
     • Use ->disableOriginalConstructor() or
     • Manually set up the mock to accept arguments.

Debugging

• Verify Mock Activation: Check if the container is using the mocker by inspecting its class:

  $this->assertInstanceOf(
      \PSS\SymfonyMockerContainer\DependencyInjection\MockerContainer::class,
      $this->container
  );
  

• Service Not Found: If $this->container->set() fails, the service ID might be incorrect. Verify with:

  $this->container->has('app.my_service'); // Returns bool
  

• Mock Not Triggered: Ensure expectations are set correctly. Use ->shouldReceive() for older PHPUnit versions:

  $mock->shouldReceive('methodName')
       ->once()
       ->andReturn('mocked value');
  

Extension Points

1. Custom Mock Factories: Extend the mocker to support custom mock creation:

   $this->container->set('app.custom_service', $this->createCustomMock());
   

   Example factory method:

   protected function createCustomMock() {
       return $this->getMockBuilder('App\Service\CustomService')
           ->setMethods(['customMethod'])
           ->getMock();
   }
   

2. Reset Mocks Between Tests: Use PHPUnit's afterEach() to reset the container:

   public function tearDown(): void {
       $this->container = static::createClient()->getContainer();
   }
   

3. Mocking Private Methods: Enable private method mocking (PHPUnit 5.3+):

   $mock = $this->getMockBuilder('App\Service\PrivateService')
       ->setMethods(['privateMethod'])
       ->getMock();
   $mock->expects($this->any())
        ->method('privateMethod')
        ->will($this->returnValue('mocked'));