`DOMNamedNodeMap`, `Dom\NamedNodeMap`, `DOMNodeList`, `Dom\NodeList`, `Dom\HTMLCollection`, and `Dom\DtdNamedNodeMap` raises `UndefinedMethod - 5:16 - Method DOMNamedNodeMap::offsetGet does not exist`

[Girgias]

Similar to phpstan/phpstan#12235.

Some internal classes do not implement ArrayAccess but allow accessing offsets regardless.

This would be fixed on the PHP side with https://wiki.php.net/rfc/container-offset-behaviour

[psalm-github-bot]

Hey @Girgias, can you reproduce the issue on https://psalm.dev? These will be used as phpunit tests when implementing the feature or fixing this bug.

[Girgias]

Psalm snippet: https://psalm.dev/r/f52aab0ba2

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/f52aab0ba2

<?php

function takesAnInt(DOMElement $e): ?DOMAttr {
    if ($e->hasAttributes()) {
        return $e->attributes[0];
    }
    return null;
}

Psalm output (using commit 765dcbf):

ERROR: UndefinedMethod - 5:16 - Method DOMNamedNodeMap::offsetGet does not exist

INFO: MixedReturnStatement - 5:16 - Could not infer a return type