class ControllerGenerator extends Generator
{
    // ...

    public function generate(BundleInterface $bundle, $controller, array $actions = array())
    {
        // ...
    }
}

class GenerateControllerCommand extends ContainerAwareCommand
{
    private $generator;

    /**
     * @see Command
     */
    public function configure()
    {
        // ...
    }

    public function execute(InputInterface $input, OutputInterface $output)
    {
        // ...

        $generator = $this->generator;
        $generator->generate($bundle, $controller);

        // ...
    }

    protected function getGenerator()
    {
        if (null === $this->generator) {
            $this->generator = new ControllerGenerator($this->getContainer()->get('filesystem'), __DIR__.'/../Resources/skeleton/bundle');
        }

        return $this->generator;
    }

    public function setGenerator(ControllerGenerator $generator)
    {
        $this->generator = $generator;
    }
}

class GenerateControllerCommandTest extends GenerateCommandTest
{
    public function testNonInteractiveCommand()
    {
        $bundle = 'FooBarBundle';
        $controller = 'PostController';

        $input = array(
            'command' => 'generate:controller',
            '--bundle' => $bundle,
            '--controller' => $controller,
        );

        $application = $this->getApplication();
        $commandTester = $this->getCommandTester($input);
        $generator = $this->getGenerator();

        $generator
            ->expects($this->once())
            ->method('generate')
            ->with($this->getContainer()->get('kernel')->getBundle($bundle), $controller)
        ;

        $commandTester->execute($input, array('interactive' => false));
    }

    protected function getCommandTester($input = '')
    {
        return new CommandTester($this->getCommand($input));
    }

    protected function getCommand($input = '')
    {
        return $this->getApplication($input)->find('generate:controller');
    }

    protected function getApplication($input = '')
    {
        $application = new Application();

        $command = new GenerateControllerCommand();
        $command->setContainer($this->getContainer());
        $command->setHelperSet($this->getHelperSet($input));
        $command->setGenerator($this->getGenerator());

        $application->add($command);

        return $application;
    }

    protected function getGenerator()
    {
        // get a noop generator
        return $this
            ->getMockBuilder('SensioBundleGeneratorBundleGeneratorControllerGenerator')
            ->disableOriginalConstructor()
            ->setMethods(array('generate'))
            ->getMock()
        ;
    }
}

$ phpunit TestsCommandGenerateControllerCommandTest

     PHPUnit 3.7.0 by Sebastian Bergmann.

     Configuration read from E:Wouterwebwampwwwwjsnipvendorsensiogenerator-bundleSensioBundleGeneratorBundlephpunit.xml.dist

     F

     Time: 2 seconds, Memory: 7.25Mb

     There was 1 failure:

     1) SensioBundleGeneratorBundleTestsCommandGenerateControllerCommandTest::testNonInteractiveCommand
     Expectation failed for method name is equal to <string:generate> when invoked 1 time(s).
     Method was expected to be called 1 times, actually called 0 times.

     E:Wouterwebwampbinphpphp5.3.5PEARphpunit:46

     FAILURES!
     Tests: 1, Assertions: 7, Failures: 1.

$generator = $this->getGenerator();

    $generator
        ->expects($this->once())
        ->method('generate')
        ->with($this->getContainer()->get('kernel')->getBundle($bundle), $controller)
    ;

    $commandTester->execute($input, array('interactive' => false));
}

protected function getApplication() {
    //...
    $command->setGenerator($this->getGenerator());
    //...
}