tagRegExp hangs with certain URLs: Catastrophic backtracking?

[Esowteric]

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The following URL causes a node.js app to hang when matching using dom-parser.

DOM source from: https://www.ecosia.org/

I created a simple vanilla javascript match script and tested the web page source against tagRegExp, and the JS script also hung. Could this be catastrophic backtracking?

tagRegExp: /(</?[a-z][a-z0-9](?::[a-z][a-z0-9])?\s*(?:\s+[a-z0-9-_]+=(?:(?:'[\s\S]?')|(?:"[\s\S]?")))\s/?>)|([^<]|<(?![a-z/]))*/gi

Thanks.

[Esowteric]

This is the script I used:

<script type="text/javascript">
var text = '... html source ...';
var text_esc = text
text_esc = text_esc.replace(/\</g, "&lt;");
text_esc = text_esc.replace(/\>/g, "&gt;");
var regex = /(<\/?[a-z][a-z0-9]*(?::[a-z][a-z0-9]*)?\s*(?:\s+[a-z0-9-_]+=(?:(?:'[\s\S]*?')|(?:"[\s\S]*?")))*\s*\/?>)|([^<]|<(?![a-z\/]))*/gi;
var found = text.match(regex);
var found_len = found.length;

document.write("Text: " + text_esc + "<br /><br />" + "Regex pattern: " + regex + "<br /><br />");

document.write("Matches: " + found_len + "<br /><br />");

for (var i=0;i<found_len;i++)
{
	found[i] = found[i].replace(/\</g, "&lt;");
	found[i] = found[i].replace(/\>/g, "&gt;");

	document.write("[" + i + "]: " + found[i] + "<br /><br />");
}
</script>

[Esowteric]

The tagRegExp match is the first stage in the process, to pull out all tags from the DOM into an array, before looking for specific tags using getElementsByTagName, getAttribute, etc.

[Esowteric]

Many thanks to Wiktor Stribiżew at Stack Overflow for this solution:

tagRegExp in /lib/Dom.js:

/(<\/?[a-z][a-z0-9]*(?::[a-z][a-z0-9]*)?\s*(?:\s+[a-z0-9-_]+=(?:'[^']*'|"[^"]*"))*\s*\/?>)|[^<]*(?:<(?![a-z\/])[^<]*)*/gi

See: https://stackoverflow.com/questions/54543223/node-js-dom-parser-tagregexp-regex-match-hangs-catastrophic-backtracking

[ershov-konst]

@Esowteric thx! I will integrate this solution soon.