Test applications services can boot

ContainerTest.php

<?php

namespace Tests\Integration;

use Symfony\Bundle\FrameworkBundle\Test\KernelTestCase;
use Symfony\Bundle\FrameworkBundle\Test\TestContainer;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\DependencyInjection\Definition;

class ContainerTest extends KernelTestCase
{
    public function testContainer()
    {
        static::bootKernel(['debug' => true]);
        /** @var TestContainer $container */
        $container = static::getContainer();
        /** @var string $projectDir */
        $projectDir = $container->getParameter('kernel.project_dir');
        /** @var string $containerDumpFile */
        $containerDumpFile = $container->getParameter('debug.container.dump');
        /** @var ContainerBuilder $dumpedContainer */
        $dumpedContainer = unserialize(file_get_contents(substr_replace($containerDumpFile, '.ser', -4)));

        $count = 0;

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

            try {
                $container->get($id);
            } catch (\Throwable $e) {
                $this->fail($e->getMessage());
            }
            ++$count;
        }

        $this->addToAssertionCount($count);
    }

    private function getFilterList(): array
    {
        return [
            \App\Foo\Bar::class,
        ];
    }

    private function isSkipped(string $id, Definition $service, ContainerBuilder $builder, string $projectDir): bool
    {
        if (\in_array($id, $this->getFilterList(), true)) {
            return true;
        }

        if (str_starts_with($id, '.')) {
            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
        }

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

        $filename = $rc->getFileName();
        if (!str_starts_with($filename, "{$projectDir}/src")) {
            return true;
        }

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

        return false;
    }
}

For the record, I have updated the gist for Symfony 7.4+

Important

for older symfony version, please check older revisions