TestDefaultExceptionSubscriber example

  public function testOnExceptionWithUnknownFormat() {
    $config_factory = $this->getConfigFactoryStub();

    $kernel = $this->prophesize(HttpKernelInterface::class);
    $request = Request::create('/test');
    // \Drupal\Core\StackMiddleware\NegotiationMiddleware normally takes care     // of this so we'll hard code it here.     $request->setRequestFormat('bananas');
    $e = new MethodNotAllowedHttpException(['POST', 'PUT'], 'test message');
    $event = new ExceptionEvent($kernel->reveal(), $request, HttpKernelInterface::MAIN_REQUEST, $e);
    $subscriber = new TestDefaultExceptionSubscriber($config_factory);
    $subscriber->setStringTranslation($this->getStringTranslationStub());
    $subscriber->onException($event);
    $response = $event->getResponse();

    $this->assertInstanceOf(Response::class, $response);
    $this->assertStringStartsWith('The website encountered an unexpected error. Please try again later.<br><br><em class="placeholder">Symfony\Component\HttpKernel\Exception\MethodNotAllowedHttpException</em>: test message in ', $response->getContent());
    $this->assertEquals(405, $response->getStatusCode());
    $this->assertEquals('POST, PUT', $response->headers->get('Allow'));
    // Also check that the text/plain content type was added.     $this->assertEquals('text/plain', $response->headers->get('Content-Type'));
  }

}