const regex = new RegExp('(?:\\n\\s{8,}(.*))|(?:\\n\\s{6,}(]|}))', 'mg')
const str = `{
"layer1": {
"layer2": {
"layer3_1": [
{
"x": 1,
"y": 7
},
{
"x": 0,
"y": 4
},
{
"x": 5,
"y": 3
},
{
"x": 6,
"y": 9
}
],
"layer3_2": "string"
}
}
}`;
const subst = `\1\2`;
// The substituted value will be contained in the result variable
const result = str.replace(regex, subst);
console.log('Substitution result: ', result);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for JavaScript, please visit: https://developer.mozilla.org/en/docs/Web/JavaScript/Guide/Regular_Expressions