Readonly liskov violations in new Dom API

Description

The following code:

<?php
$xml = <<<END
<?xml version="1.0" encoding="UTF-8"?>
<root>
    <child />
</root>
END;

$doc = Dom\XMLDocument::createFromString($xml);
$root = $doc->firstChild;
$text = $root->firstChild;
$child = $root->firstElementChild;

try {
    $text->nodeValue = 'Hello';
} catch (Throwable $t) {
    var_dump($t->getMessage());
}

try {
    $child->nodeValue = 'Hello';
} catch (Throwable $t) {
    var_dump($t->getMessage());
}

try {
    $doc->nodeValue = 'Hello';
} catch (Throwable $t) {
    var_dump($t->getMessage());
}


try {
    $text->textContent = 'Hello';
} catch (Throwable $t) {
    var_dump($t->getMessage());
}

try {
    $child->textContent = 'Hello';
} catch (Throwable $t) {
    var_dump($t->getMessage());
}

try {
    $doc->textContent = 'Hello';
} catch (Throwable $t) {
    var_dump($t->getMessage());
}

Resulted in this output:

string(55) "Cannot modify readonly property Dom\Element::$nodeValue"
string(59) "Cannot modify readonly property Dom\XMLDocument::$nodeValue"
string(61) "Cannot modify readonly property Dom\XMLDocument::$textContent"

But I expected this output instead:

In user code this would result in:

Fatal error: Cannot redeclare non-readonly property X::$y as readonly Y::$y

Since I've found multiple of these exploring the new Dom API it probably needs a closer look.

Tested in both docker (php:8.4-rc-alpine version 8.4.0beta3) and 3v4l

PHP Version

8.4.0beta3

Operating System

No response

Inizia riproducendo il comportamento della proprietà readonly dall’esempio PHP dell’issue rispetto alla nuova Dom API, quindi esamina le dichiarazioni e le relazioni di ereditarietà di nodeValue e textContent su Dom\Element e Dom\XMLDocument. Il lavoro è completato quando le violazioni di compatibilità di Liskov segnalate sono risolte senza gli errori fatali della proprietà readonly mostrati.