Replace single quotes, but not if within double quotes to use JSON.parse()

I need a solution to only exchange pairs of single quotes, which are NOT within a pair of double quotes.

A simplified example (original is > 100 KB):

['Element1',"Element's2",{"Element3":"E3"},'Element4']

In this example Element's2 should not become Element"s2, but 'Element1' should become "Element1".

Background: I need to extract some website data contained in big Javascript blocks. To get it i need JOSN.parse() which does not accept single quotes (') as quotes.

but i can not simply use replace(/'/g, '"'), because the single quote is also used as apostrophe in some texts like: "that's it".

BTW: As @hakre recommenced, a much more simple solution for my case was to use eval() instead of JOSN.parse(). With eval() there was no need to exchange the single quotes.

Solution

I made a second variant, which also cares about escaped quotes like:[\'Element1\',"Element's2",{"Elements3":"E3"},'Element\'s4']

but it is a bit slower and the code looks a bit more complicated (so i use the other variant):

function convert(input) {

    var openQuote 
    var close = {symbol:null,level:0,firstPos:null}
    openQuote = close;
    const singleQuote = "'"
    const doubleQuote = '"'
    const replaceBy = '"'
    var pairCount = 0
    var data = Array.from(input)

    function replacePair(data, newChar, firstPos, secondPos) {
        data[firstPos] =  newChar;
        data[secondPos] =  newChar;
        pairCount++
    }

    function checkEscaped (data, pos, level = 0) {
        if (pos <= 0) return level
        if (data[pos-1] ==  "\\")  { return checkEscaped(data,pos-1,level+1) }
        return level
    }

    function checkQuotes(data,pos){

        if (data[pos] == singleQuote) {
        let level = checkEscaped(data, pos)

          if (openQuote.symbol == null) {openQuote = {symbol: singleQuote, level: level, firstPos: pos}; return}
          if (openQuote.symbol == singleQuote && openQuote.level == level) {replacePair(data,replaceBy,openQuote.firstPos,pos); openQuote = close; return;}
          return
        }

        if (data[pos] == doubleQuote) {
        let level = checkEscaped(data, pos)

          if (openQuote.symbol == null) {openQuote = {symbol: doubleQuote, level: level, firstPos: pos}; return}
          if (openQuote.symbol == doubleQuote && openQuote.level == level) {openQuote = close; return;}
        }
    }

    for (let i=0; i < data.length; i++) {
      checkQuotes(data,i)
    }

    var result = data.join("");
    console.log(pairCount , "Pairs of Single Quotes exchanged")
    return result
}

document.getElementById('start').addEventListener('click', () => {
    var dataIn = document.getElementById('input').value;
    var output = document.getElementById('output').value = convert(dataIn)
});

<html><body>
<button id="start">start</button><BR>

Input:<br><textarea id="input" name="w3review" rows="2" cols="100" spellcheck="false">
[\'Element1\',"Element's2",{"Elements3":"E3"},'Element\'s4']
</textarea><BR>

Output:<br><textarea id="output" name="w3review" rows="2" cols="100" spellcheck="false"></textarea>
 
</body></html>