fix quote regexp

[lifaon74]

Hi, first thanks for your excellent library !

I found a strange behaviour when using attribute selectors:

a[attr="abcde"][attr="123"]

link

The second attribute returns:

	{
		"type": "attribute",
		"content": "[attr=\"§\"]",
		"name": "attr",
		"operator": "=",
		"value": "\"§\"",
		"pos": [
			11,
			21
		]
	}

Note the §.

I found and fixed the issue on the quote replace regexp.

[LeaVerou]

Hi there,
Thank you for looking into this!
Could you elaborate on this a bit? What was causing the issue and how did you fix it?
It would help me review the PR, as the answers are not immediately obvious to me by looking at your edit.

[lifaon74]

Ok, so as you commented:

// FIXME Does not account for escaped backslashes before a quote
selector = selector.replace(/(['"])(\\\1|.)+?\1/g, (str, quote, content, start) => {

Actually this regexp is incorrect in 2 points:

• (\\\1|.)+ this puts only the last matching char in content. ((?:\\\1|.)+) is correct
  • this is what triggers the reported bug: link
• you didn't handle escaped quotes, as it is actually not a simple task (you commented about it)

A more accurate regexp is: /(?:"((?:[^"\\]|\\.)*)")|(?:'((?:[^'\\]|\\.)*)')/g

• split: "((?:[^"\\]|\\.)*)" -> select in quotes and handle backslashes

[lifaon74]

Note: the regexp can't handle \\\\ (ex: "ab\\\\"hg"). Actually I guess a regexp can't handle properly every escapes and quotes in string. For this a proper parser may be used.

[lifaon74]

Hi, any news ?

[jrandolf]

Fixed in #57