Autoloading of functions

[mathroc]

Hi!

My project depends on symfony/string but when I'm doing something like:

<?php

declare(strict_types=1);

use function Symfony\Component\String\u;

echo u('hello');

with this composer.json:

{
    "require": {
        "symfony/string": "^6.0"
    }
}

Here is Psalm output:

$ psalm --debug index.php 
Registering autoloaded files
   /var/www/tmp/repro/vendor/autoload.php
   /var/www/tmp/repro/vendor/composer/autoload_real.php
   /var/www/tmp/repro/vendor/composer/platform_check.php
   /var/www/tmp/repro/vendor/composer/autoload_static.php
   /var/www/vendor/composer/autoload_files.php

...

Finished registering stub files
Analyzing files...
Getting /var/www/tmp/repro/index.php
Analyzing /var/www/tmp/repro/index.php

ERROR: UndefinedFunction - tmp/repro/index.php:7:6 - Function Symfony\Component\String\u does not exist (see https://psalm.dev/021)
echo u('hello');


------------------------------
1 errors found
------------------------------

In vendor/symfony/string/composer.json, I can see this:

"autoload": {
        "psr-4": { "Symfony\\Component\\String\\": "" },
        "files": [ "Resources/functions.php" ],
        "exclude-from-classmap": [
            "/Tests/"
        ]
    },

and in vendor/symfony/string/Resources/functions.php:

namespace Symfony\Component\String;

if (!\function_exists(u::class)) {
    function u(?string $string = ''): UnicodeString
    {
        return new UnicodeString($string ?? '');
    }
}

...

So I don't know what's missing here, any help is appreciated :)

[Tobion]

The same problem for example also happens when using the \Symfony\Component\DependencyInjection\Loader\Configurator\service function. The functions defined in symfony/dependency-injection/Loader/Configurator/ContainerConfigurator.php are not autoloaded but rather loaded through the use of the class. So psalm cannot do much in this case except loading the file as stub automatically.