Test applications services can boot

ContainerTest.php

<?php

namespace Tests\Integration;

use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
use Symfony\Component\Config\FileLocator;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Definition;
use Symfony\Component\DependencyInjection\Loader\XmlFileLoader;

class ContainerTest extends KernelTestCase
{
    private const FILTER_LIST = [
        // some services can exist only in dev or prod (thus not in test env)
        // or some services are behind some features flags
        // or some services are static (thus they are not real service)
    ];

    public function testContainer()
    {
        static::bootKernel(['debug' => true]);
        $projectDir = static::getContainer()->getParameter('kernel.project_dir');
        $container = static::getContainer();

        $builder = new ContainerBuilder();
        $loader = new XmlFileLoader($builder, new FileLocator());
        $loader->load($container->getParameter('debug.container.dump'));

        $count = 0;

        foreach ($builder->getDefinitions() as $id => $service) {
            if ($this->isSkipped($id, $service, $builder, $projectDir)) {
                continue;
            }

            $container->get($id);
            ++$count;
        }

        $this->addToAssertionCount($count);
    }

    private function isSkipped(string $id, Definition $service, ContainerBuilder $builder, string $projectDir): bool
    {
        if (str_starts_with($id, '.instanceof.') || str_starts_with($id, '.abstract.') || str_starts_with($id, '.errored.')) {
            return true; // Symfony internal stuff
        }

        if ($service->isAbstract()) {
            return true; // Symfony internal stuff
        }

        $class = $service->getClass();
        if (!$class) {
            return true; // kernel, or alias, or abstract
        }

        if (\in_array($class, self::FILTER_LIST)) {
            return true;
        }

        $rc = $builder->getReflectionClass($class, false);
        if (!$rc) {
            return true;
        }

        $filename = $rc->getFileName();
        if (!str_starts_with($filename, "{$projectDir}/src")) {
            return true; // service class not in tests/Integration
        }

        if ($rc->isAbstract()) {
            return true;
        }

        return false;
    }
}

FYI, I ended up with something like this as a PoC:

class ContainerTest extends KernelTestCase
{
    private const FILTER_LIST = [
        // some services can exist only in dev or prod (thus not in test env)
        // or some services are behind some features flags
        // or some services are static (thus they are not real service)
    ];

    public function testContainer(): void
    {
        static::bootKernel(['debug' => true]);
        $projectDir = static::getContainer()->getParameter('kernel.project_dir');
        $container = static::getContainer();

        $this->bootstrapContainer($container);

        $builder = new ContainerBuilder();
        $loader = new XmlFileLoader($builder, new FileLocator());
        $loader->load($container->getParameter('debug.container.dump'));

        $invalidServices = [];
        $count = 0;

        foreach ($builder->getDefinitions() as $id => $service) {
            if ($this->isSkipped($id, $service, $builder, $projectDir)) {
                continue;
            }

            try {
                $container->get($id);
            } catch (\Throwable $e) {
                $invalidServices[] = sprintf('[%s] %s', $id, $e->getMessage());
                continue;
            }

            ++$count;
        }

        $this->addToAssertionCount($count);

        if (count($invalidServices) > 0) {
            throw new \RuntimeException(sprintf(
                "Invalid services found: \n  - %s",
                implode("\n\n  - ", $invalidServices)
            ));
        }
    }

    private function isSkipped(string $id, Definition $service, ContainerBuilder $builder, string $projectDir): bool
    {
        if (str_starts_with($id, '.instanceof.')
            || str_starts_with($id, '.abstract.')
            || str_starts_with($id, '.errored.')
            || $service->isAbstract() // Incomplete definitions that can't be instantiated
            || $service->isSynthetic() // Synthetic services don't actually have a definition, these are set in runtime
            || $service->isLazy() // @TODO support lazy services
        ) {
            return true; // Symfony internal stuff
        }

        $class = $service->getClass();
        if (!$class) {
            return true; // kernel, or alias, or abstract
        }

        if (\in_array($class, self::FILTER_LIST)) {
            return true;
        }

        $rc = $builder->getReflectionClass($class, false);
        if (!$rc) {
            return true;
        }

        $filename = $rc->getFileName();
        if (false === $filename || str_starts_with($filename, "{$projectDir}/vendor/symfony")) {
            return true;
        }

        if ($rc->isAbstract()) {
            return true;
        }

        return false;
    }

    /**
     * Do all the stuff required for bootstrapping services/factories, that are used when services are being built
     */
    private function bootstrapContainer(ContainerInterface $container): void {
    }
}

The differences from gist's version:

• iterate over all service, collect all the errors and print them at once at the end
• ignore synthetic services (these are meant to be set in runtime, no need to check them)
• ignore lazy services (it's something to tackle, I had some problems and did not want to spend much time on it)
• ignore Symfony services registered from vendor/symfony, instead of narrowing to src only (our app has several dirs with production code, I did not want to list them all or to prepare complex logic)
• skip if service reflection returned false

Anyway, thanks for sharing, it was good to make some kind of experiment. What I found more than lint:container is that we rely on EventDispatcher, not on EventDispatcherInterface, so when traceable event dispatcher is injected in test environment, there's TypeError, which means we should fix the signatures and use the interface as a contract.

PS. in our case bootstrapContainer() has logic, I just removed it as it's crafted for our code. But if there are any things that need to be pre-defined before services are created (like $_SERVER['HTTP_CLIENT_IP'] for example), you also need to do it before iterating over container.

hey @lyrixx

thanks for this snippet.

I'm trying to implement this in one huge project, and I'm facing some memory limit problems. I tried to run with 'debug' => false, or to shutdown kernel, but still have a huge memory usage with this test. Do you have some hints about this? thanks!

@nikophil

On project I'm working ATM:

• 6557 services in total

• OK (1 test, 1008 assertions)
  Time: 00:01.455, Memory: 119.00 MB
  

  so 1008 services tested

So it looks like it does not consume too much memory

Maybe you have a memory leak somewhere...

we have more than 20.000 services and 4000 services tested, memory consumption ends at ~600 Mo just for this test 😞

Now that XmlFileLoader is deprecated, what's the best way to resolve this deprecation here? :)

Hello, I haven't tried it yet. However, I think you could take inspiration from this: https://github.com/symfony/symfony/blob/8.1/src/Symfony/Bundle/FrameworkBundle/Command/BuildDebugContainerTrait.php#L33

Thanks, that works well