How to test PipelineAndRoutesDelegator?

Questions Mezzio
5

Sure!

Let’s say you have the following delegator factory registering a single route:

namespace Acme;

use Psr\Container\ContainerInterface;

class HomeRouteDelegatorFactory
{
    public function __invoke(ContainerInterface $container, $serviceName, callable $callback)
    {
        $app = $callback();
        $app->get('/', Action\HomePageAction::class, 'home');
        return $app;
    }
}

You could write a test like the following:

<?php
namespace AcmeTest;

use Acme\Action\HomePageAction;
use Acme\HomeRouteDelegatorFactory;
use PHPUnit\Framework\TestCase;
use Psr\Container\ContainerInterface;
use Zend\Expressive\Application;

class HomeRouteDelegatorFactoryTest extends TestCase
{
    public function testRegistersHomePageRoute()
    {
        $container = $this->prophesize(ContainerInterface::class)->reveal();

        $app = $this->prophesize(Application::class);
        $app->get('/', HomePageAction::class, 'home')->shouldBeCalled();
        $callback = function () use ($app) {
            return $app->reveal();
        };

        $delegator = new HomeRouteDelegatorFactory();

        $result = $delegator($container, Application::class, $callback);

        $this->assertSame($app->reveal(), $result);
    }
}

The above mocks the Application class, writes expectations against it, and
then creates a callback that will return it. This is passed to the delegator,
and we can then verify the Application is what is returned.