class MailManagerTest

class MailManagerTest extends UnitTestCase {
    
    /**
     * The cache backend to use.
     *
     * @var \Drupal\Core\Cache\CacheBackendInterface|\PHPUnit\Framework\MockObject\MockObject
     */
    protected $cache;
    
    /**
     * The module handler.
     *
     * @var \Drupal\Core\Extension\ModuleHandlerInterface|\PHPUnit\Framework\MockObject\MockObject
     */
    protected $moduleHandler;
    
    /**
     * The configuration factory.
     *
     * @var \Drupal\Core\Config\ConfigFactoryInterface|\PHPUnit\Framework\MockObject\MockObject
     */
    protected $configFactory;
    
    /**
     * The plugin discovery.
     *
     * @var \Drupal\Component\Plugin\Discovery\DiscoveryInterface|\PHPUnit\Framework\MockObject\MockObject
     */
    protected $discovery;
    
    /**
     * The renderer.
     *
     * @var \Drupal\Core\Render\RendererInterface|\PHPUnit\Framework\MockObject\MockObject
     */
    protected $renderer;
    
    /**
     * The mail manager under test.
     *
     * @var \Drupal\Tests\Core\Mail\TestMailManager
     */
    protected $mailManager;
    
    /**
     * A list of mail plugin definitions.
     *
     * @var array
     */
    protected $definitions = [
        'php_mail' => [
            'id' => 'php_mail',
            'class' => 'Drupal\\Core\\Mail\\Plugin\\Mail\\PhpMail',
        ],
        'test_mail_collector' => [
            'id' => 'test_mail_collector',
            'class' => 'Drupal\\Core\\Mail\\Plugin\\Mail\\TestMailCollector',
        ],
    ];
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() : void {
        parent::setUp();
        // Prepare the default constructor arguments required by MailManager.
        $this->cache = $this->createMock('Drupal\\Core\\Cache\\CacheBackendInterface');
        $this->moduleHandler = $this->createMock('Drupal\\Core\\Extension\\ModuleHandlerInterface');
        // Mock a Discovery object to replace AnnotationClassDiscovery.
        $this->discovery = $this->createMock('Drupal\\Component\\Plugin\\Discovery\\DiscoveryInterface');
        $this->discovery
            ->expects($this->any())
            ->method('getDefinitions')
            ->willReturn($this->definitions);
    }
    
    /**
     * Sets up the mail manager for testing.
     */
    protected function setUpMailManager($interface = []) {
        // Use the provided config for system.mail.interface settings.
        $this->configFactory = $this->getConfigFactoryStub([
            'system.mail' => [
                'interface' => $interface,
            ],
            'system.site' => [
                'mail' => 'test@example.com',
            ],
        ]);
        $logger_factory = $this->createMock('\\Drupal\\Core\\Logger\\LoggerChannelFactoryInterface');
        $string_translation = $this->getStringTranslationStub();
        $this->renderer = $this->createMock(RendererInterface::class);
        // Construct the manager object and override its discovery.
        $this->mailManager = new TestMailManager(new \ArrayObject(), $this->cache, $this->moduleHandler, $this->configFactory, $logger_factory, $string_translation, $this->renderer);
        $this->mailManager
            ->setDiscovery($this->discovery);
        // @see \Drupal\Core\Plugin\Factory\ContainerFactory::createInstance()
        $container = new ContainerBuilder();
        $container->set('config.factory', $this->configFactory);
        \Drupal::setContainer($container);
    }
    
    /**
     * Tests the getInstance method.
     *
     * @covers ::getInstance
     */
    public function testGetInstance() {
        $interface = [
            'default' => 'php_mail',
            'example_testkey' => 'test_mail_collector',
        ];
        $this->setUpMailManager($interface);
        // Test that an unmatched message_id returns the default plugin instance.
        $options = [
            'module' => 'foo',
            'key' => 'bar',
        ];
        $instance = $this->mailManager
            ->getInstance($options);
        $this->assertInstanceOf('Drupal\\Core\\Mail\\Plugin\\Mail\\PhpMail', $instance);
        // Test that a matching message_id returns the specified plugin instance.
        $options = [
            'module' => 'example',
            'key' => 'testkey',
        ];
        $instance = $this->mailManager
            ->getInstance($options);
        $this->assertInstanceOf('Drupal\\Core\\Mail\\Plugin\\Mail\\TestMailCollector', $instance);
    }
    
    /**
     * Tests that mails are sent in a separate render context.
     *
     * @covers ::mail
     */
    public function testMailInRenderContext() {
        $interface = [
            'default' => 'php_mail',
            'example_testkey' => 'test_mail_collector',
        ];
        $this->setUpMailManager($interface);
        $this->renderer
            ->expects($this->exactly(1))
            ->method('executeInRenderContext')
            ->willReturnCallback(function (RenderContext $render_context, $callback) {
            $message = $callback();
            $this->assertEquals('example', $message['module']);
        });
        $this->mailManager
            ->mail('example', 'key', 'to@example.org', 'en');
    }

}