Document how to "integration" test private services

[weaverryan]

Question:

What if you do container->get() some services in tests.

Answer:

The proper solution would be to create a public alias for the service you want to test in the test environment only:

# app/config/config_test.yml
services:
    test_alias.AppBundle\Service\MyService:
        alias: 'AppBundle\Service\MyService'
        public: true # require on SF4, where everything is private by default

Then, you would actually fetch test_alias.AppBundle\Service\MyService out of the container in your unit test. It's a nice idea too: you only need to expose your service as public in the test environment.

[soullivaneuh]

Nice idea.

Could be also named:

• test.AppBundle\Service\MyService
• AppBundle\Service\MyService.test

[theofidry]

Not ideal but I avoided any pain by making all my services public thanks a compiler pass for my libraries...

[weaverryan]

I added this to the 4.0 milestone, so we will remember to do it. But a PR for this should go into 3.3 I believe.

[weaverryan]

... with a note that the config paths will need to change when merged into 4.0. We're going to be trying to remember to do that a lot :)

[nicolas-grekas]

I'd suggest to prefix the aliases by test. as a convention we would advocate.

[theofidry]

@nicolas-grekas I know you're not happy with it but I don't use the container as a service locator anywhere except in my tests so having this limitation makes really no sense to me.

I've got the choice between updating hundreds of service definitions and registering a compiler pass turning my library/application services into public services. I don't have much time for it, so I need to be pragmatic, the former solution is too much of a burden.

Another idea: maybe having a "non secure" container registered as a different service name than container which one could use during tests? This way you wouldn't need to change any alias but instead simply doing something like:

$kernel->getTestContainer()->get('foo');
// or
$kernel->getContainer()->get('test_container')->get('foo');

[nicolas-grekas]

@6ecuk don't do that: if you happen to use a service in eg your controllers, your tests will be green, but your prod will fail. The worst combination of events.

[nicolas-grekas]

@6ecuk you do as you want of course - but advocating this is giving a footgun to ppl

[theofidry]

@6ecuk your snippet is incomplete as you are missing the aliases as well. But already mentioned I would strongly suggest against it if there is commands or controllers using the container as a service locator.

@nicolas-grekas what do you think of my second proposal? I think that would be a more acceptable compromise than the two extremes we currently see (alias everything or make everything public).

[nicolas-grekas]

@theofidry a container is a compiled php class. The removed services are actually removed. So there is "hand" to get them. The only way to make that work is to dump another container just for tests. Which is actually what the compiler pass is doing. I don't think there is anything in between.

[soullivaneuh]

@theofidry The only is issue I see with your method is if I test a controller doing this:

$this->get('a.service.that.should.be.private');

It will works on your test, but not in production neither and dev env.