Allow to bind inline services by type and name

[vudaltsov]

return function(ContainerConfigurator $configurator) {
    $services = $configurator->services()
        ->defaults()
        ->bind(Foo::class.' $foo', inline_service(Foo::class))
    ;
};

Currently it throws Invalid binding for service "": named arguments must start with a "$", and FQCN must map to references. Neither applies to binding "Foo $foo", while binding inline service just by name works.

[nicolas-grekas]

We might improve the error message, but what it says is that only references are allowed when binding services, and this looks legit to me. Otherwise, there is some non-intuitive issue that is going to happen, eg: should all inline services lead to different instances or should they all refer to the same one ? (note: this would need a ... reference).

[vudaltsov]

@nicolas-grekas, I understand your reasoning, but as a developer I face the following inconsistency. I can bind an inline service by name only, but cannot bind by type and name. So it would be more logical to forbid binding inline services completely, or allow to bind them both ways.

[nicolas-grekas]

Would you mind investigating in the code where this difference happens? I'm surprised that binding by name-only works with inline services.

[vudaltsov]

symfony/src/Symfony/Component/DependencyInjection/Loader/Configurator/Traits/BindTrait.php

Lines 37 to 39 in 2dcf313

	if (!preg_match('/^(?:(?:array|bool|float|int|string)[ \t]*+)?\$/', $nameOrFqcn) && !$valueOrRef instanceof Reference) {
	throw new InvalidArgumentException(sprintf('Invalid binding for service "%s": named arguments must start with a "$", and FQCN must map to references. Neither applies to binding "%s".', $this->id, $nameOrFqcn));
	}

The first matching group in the regexp is optional. Thus, during a call ->bind('$name', inline_service()), preg_match evaluates to true and !preg_match evaluates to false, which immediately prevents exception from being thrown.

[nicolas-grekas]

PR welcome @vudaltsov, let's make this consistent.