class DOMNodeComparator

final class DOMNodeComparator extends ObjectComparator {
    public function accepts(mixed $expected, mixed $actual) : bool {
        return $expected instanceof DOMNode && $actual instanceof DOMNode;
    }
    
    /**
     * @throws ComparisonFailure
     */
    public function assertEquals(mixed $expected, mixed $actual, float $delta = 0.0, bool $canonicalize = false, bool $ignoreCase = false, array &$processed = []) : void {
        assert($expected instanceof DOMNode);
        assert($actual instanceof DOMNode);
        $expectedAsString = $this->nodeToText($expected, true, $ignoreCase);
        $actualAsString = $this->nodeToText($actual, true, $ignoreCase);
        if ($expectedAsString !== $actualAsString) {
            $type = $expected instanceof DOMDocument ? 'documents' : 'nodes';
            throw new ComparisonFailure($expected, $actual, $expectedAsString, $actualAsString, sprintf("Failed asserting that two DOM %s are equal.\n", $type));
        }
    }
    
    /**
     * Returns the normalized, whitespace-cleaned, and indented textual
     * representation of a DOMNode.
     */
    private function nodeToText(DOMNode $node, bool $canonicalize, bool $ignoreCase) : string {
        if ($canonicalize) {
            $document = new DOMDocument();
            try {
                $c14n = $node->C14N();
                assert(!empty($c14n));
                @$document->loadXML($c14n);
            } catch (ValueError) {
            }
            $node = $document;
        }
        $document = $node instanceof DOMDocument ? $node : $node->ownerDocument;
        $document->formatOutput = true;
        $document->normalizeDocument();
        $text = $node instanceof DOMDocument ? $node->saveXML() : $document->saveXML($node);
        return $ignoreCase ? mb_strtolower($text, 'UTF-8') : $text;
    }

}