Generics issues with PHPStorm

example1.php

<?php

declare(strict_types=1);

// composer require webonyx/graphql-php

use GraphQL\Language\AST\DirectiveNode;
use GraphQL\Language\AST\FieldNode;
use GraphQL\Language\AST\NodeList;

include __DIR__ . '/vendor/autoload.php';

/**
 * @var NodeList<DirectiveNode> $list
 */
$list = new NodeList([
    new DirectiveNode([])
]);

foreach ($list as $item) {
    // this works, PHPStorm understands $item is DirectiveNode
    echo $item::class . PHP_EOL;
}

// But now we do this:

$fieldNode = new FieldNode([
    'directives' => new NodeList([
        new DirectiveNode([])
    ])
]);

foreach ($fieldNode->directives as $item) {
    // PHPStorm thinks $item is mixed
    echo $item::class . PHP_EOL;
}

example2.php

<?php

declare(strict_types=1);

include __DIR__ . '/vendor/autoload.php';

final class ChunkedIterator
{
    /**
     * @template TKey of array-key
     * @template TValue of mixed
     *
     * @param Iterator<TKey, TValue> $iterable
     *
     * @return Generator<int, non-empty-array<TKey, TValue>>
     */
    public static function chunk(Iterator $iterable, int $chunkSize) : Generator
    {
        $chunk = [];

        for ($i = 0; $iterable->valid(); ++$i) {
            $chunk[$iterable->key()] = $iterable->current();

            if (count($chunk) === $chunkSize) {
                yield $chunk;
                $chunk = [];
            }

            $iterable->next();
        }

        if ($chunk !== []) {
            yield $chunk;
        }
    }
}

/**
 * @return Generator<int, array{id: int}>
 */
function generator() : Generator
{
    for ($i = 0; $i < 13; ++$i) {
        yield ['id' => $i];
    }
}

$iterator = ChunkedIterator::chunk(generator(), 3);
// \PHPStan\dumpType($iterator);
// Dumped type: Generator<int, non-empty-array<int, array{id: int}>, mixed, mixed>
foreach ($iterator as $chunk) {
    // \PHPStan\dumpType($chunk);
    // Dumped type: non-empty-array<int, array{id: int}>
    // But PHPStorm thinks $chunk is $2|array|mixed
    foreach ($chunk as $item) {
        // \PHPStan\dumpType($item);
        // Dumped type: array{id: int}
        // But PHPStorm thinks $item is array|Generator
        echo $item['id'] . PHP_EOL;
    }

    echo "Flush...\n";
}

example3.php

<?php

declare(strict_types=1);

include __DIR__ . '/vendor/autoload.php';

// composer require symfony/type-info

use Symfony\Component\TypeInfo\Type;

/**
 * @template T of Type = Type
 */
interface TypeInitializer
{
    /**
     * @param T $type
     */
    public function initialize(Type $type) : void;
}

/**
 * @implements TypeInitializer<Type\ObjectType<*>>
 */
final class ObjectTypeInitializer implements TypeInitializer
{
    #[Override]
    public function initialize(Type $type) : void
    {
        // \PHPStan\dumpType($type);
        // Dumped type: Symfony\Component\TypeInfo\Type\ObjectType<*>
        
        // PHPStorm thinks $type is just a Type
    }
}