trait ContainerMockTrait in Drupal 7 to 8/9 Module Upgrader 8

trait ContainerMockTrait {

  /**
   * @var \Symfony\Component\DependencyInjection\ContainerInterface
   */
  protected $container;
  protected function mockContainer() {
    if (empty($this->container)) {

      // Using a ContainerBuilder lets us simply stick services into the
      // container, which is a whole lot easier than mocking it!
      $this->container = new ContainerBuilder();
    }
  }
  protected function mockTranslator() {
    $this
      ->mockContainer();

    // Mock the string_translation service; calling its translate()
    // method will return the original, unprocessed string.
    $translator = $this
      ->createMock('\\Drupal\\Core\\StringTranslation\\TranslationInterface');
    $translator
      ->method('translate')
      ->willReturnArgument(0);
    $this->container
      ->set('string_translation', $translator);
  }
  protected function mockLogger() {
    $this
      ->mockContainer();

    // Mock the logger.factory service and a logger channel.
    $factory = $this
      ->createMock('\\Drupal\\Core\\Logger\\LoggerChannelFactoryInterface');
    $channel = $this
      ->createMock('\\Drupal\\Core\\Logger\\LoggerChannelInterface');
    $factory
      ->method('get')
      ->willReturn($channel);
    $this->container
      ->set('logger.factory', $factory);
  }

}