Suggest packages on missing autowiring aliases

[nicolas-grekas]

When I use a type-hint for an interface that is not installed, autowiring fails with a generic message, e.g.: Cannot autowire argument $client of "App\Controller\HelloController::index()": argument "$responseFactory" of method "Symfony\Component\HttpClient\Psr18Client::__construct()" has type "Psr\Http\Message\ResponseFactoryInterface" but this class was not found.

But in this example, we could suggest a solution: compose require nyholm/psr7 will install recipes for the interface. Maybe we could display this as a suggestion when we detect that flex is installed? We would do this for packages with official recipes only to reduce the scope.

Another example is Cannot determine controller argument for "App\Controller\HelloController::index()": the $client argument is type-hinted with the non-existent class or interface: "Psr\Http\Client\ClientInterface". when psr/http-client is missing.

[moynzzz]

I would like to work on this issue @nicolas-grekas how do you suggest implementing the desired functionality in terms of which packages interfaces should be suggested. Should we extract all possible interfaces from the packages that exist in the Symfony recipes repository or some more robust way of doing that?

[nicolas-grekas]

From what I read, these two messages are found:

1. in AutowirePass::createTypeNotFoundMessage()
2. in RegisterControllerArgumentLocatorsPass::process()

I think we could add a static class in the DI component that would hard-code a few packages - let's start with only the ones mentionned in the description and see later if/how to grow the list?

[moynzzz]

Okay I'm working on a PR for this feature.

[moynzzz]

I have a qustion about how to check if flex is installed in a symfony application. I tried to check if flex class exists (Symfony\Flex\Flex) but it depends on Composer\Plugin\PluginInterface which is not autoloaded (because composer autoloader doesn't add it to the list of loaded classes which is expected we don't need it in our applications) and so the check will fail. A solution will be to check for a class that exists in the flex source like Symfony\Flex\Lock but I don't think this is the best one.

Does anybody have an idea how this can be solved?

[nicolas-grekas]

A solution will be to check for a class that exists in the flex source like Symfony\Flex\Lock

I think that's the best solution actually :)

[Simperfit]

@moynzzz Are you still working on it ?

[moynzzz]

@Simperfit Yes, I am. Sorry for the delay I was a little busy last month.