php-language-server/src/FqnUtilities.php

<?php

namespace LanguageServer\FqnUtilities;

use phpDocumentor\Reflection\{Type, Types};
use Microsoft\PhpParser;

/**
 * Returns all possible FQNs in a type
 *
 * @param Type|null $type
 * @return string[]
 */
function getFqnsFromType($type): array
{
    $fqns = [];
    if ($type instanceof Types\Object_) {
        $fqsen = $type->getFqsen();
        if ($fqsen !== null) {
            $fqns[] = substr((string)$fqsen, 1);
        }
    }
    if ($type instanceof Types\Compound) {
        for ($i = 0; $t = $type->get($i); $i++) {
            foreach (getFqnsFromType($type) as $fqn) {
                $fqns[] = $fqn;
            }
        }
    }
    return $fqns;
}