Symfony 4 : Override public services in container - php

Question

I am migrating our project to Symfony 4. In my test suites, we used PHPUnit for functional tests (I mean, we call endpoints and we check result). Often, we mock services to check different steps.
Since I migrated to Symfony 4, I am facing this issue: Symfony\Component\DependencyInjection\Exception\InvalidArgumentException: The "my.service" service is already initialized, you cannot replace it.
when we redefine it like this : static::$container->set("my.service", $mock);
Only for tests, how can I fix this issue?
Thank you

Answer 1

Replacing is deprecated since Symfony 3.3. Instead of replacing service you should try using aliases.
http://symfony.com/doc/current/service_container/alias_private.html
Also, you can try this approach:
$this->container->getDefinition('user.user_service')->setSynthetic(true);
before doing $container->set()
Replace Symfony service in tests for php 7.2

Answer 2

Finally, I found a solution. Maybe not the best, but, it's working:
I created another test container class and I override the services property using Reflection:
<?php
namespace My\Bundle\Test;
use Symfony\Bundle\FrameworkBundle\Test\TestContainer as BaseTestContainer;
class TestContainer extends BaseTestContainer
{
private $publicContainer;
public function set($id, $service)
{
$r = new \ReflectionObject($this->publicContainer);
$p = $r->getProperty('services');
$p->setAccessible(true);
$services = $p->getValue($this->publicContainer);
$services[$id] = $service;
$p->setValue($this->publicContainer, $services);
}
public function setPublicContainer($container)
{
$this->publicContainer = $container;
}
Kernel.php :
<?php
namespace App;
use Symfony\Component\HttpKernel\Kernel as BaseKernel;
class Kernel extends BaseKernel
{
use MicroKernelTrait;
public function getOriginalContainer()
{
if(!$this->container) {
parent::boot();
}
/** #var Container $container */
return $this->container;
}
public function getContainer()
{
if ($this->environment == 'prod') {
return parent::getContainer();
}
/** #var Container $container */
$container = $this->getOriginalContainer();
$testContainer = $container->get('my.test.service_container');
$testContainer->setPublicContainer($container);
return $testContainer;
}
It's really ugly, but it's working.

Answer 3

I've got a couple of tests like this (the real code performs some actions and returns a result, the test-version just returns false for every answer).
If you create and use a custom config for each environment (eg: a services_test.yaml, or in Symfony4 probably tests/services.yaml), and first have it include dev/services.yaml, but then override the service you want, the last definition will be used.
app/config/services_test.yml:
imports:
- { resource: services.yml }
App\BotDetector\BotDetectable: '#App\BotDetector\BotDetectorNeverBot'
# in the top-level 'live/prod' config this would be
# App\BotDetector\BotDetectable: '#App\BotDetector\BotDetector'
Here, I'm using an Interface as a service-name, but it will do the same with '#service.name' style as well.

Answer 4

As I understood it, it means that class X was already injected(because of some other dependency) somewhere before your code tries to overwrite it with self::$container->set(X:class, $someMock).

Answer 5

If you on Symfony 3.4 and below you can ovverride services in container regardless it privite or public. Only deprication notice will be emmited, with content similar to error message from question.
On Symfony 4.0 error from the question was thown.
But on Symfony 4.1 and above you can lean on special "test" container. To learn how to use it consider follow next links:
https://symfony.com/blog/new-in-symfony-4-1-simpler-service-testing
https://dev.to/nikolastojilj12/symfony-5-mocking-private-autowired-services-in-controller-functional-tests-24j4