Build a JSON from given query part of an URL

buildJsonFromUrlQuery.js

function buildJsonFromUrlQuery(query){
	if(!query || typeof query !== 'string' || !query.length) return {};
    
    var partsArray = query.split('&');
    var partsObject = {};

    for(let i in partsArray){
        let thisPart = partsArray[i];
        let keyValue = thisPart.split('=');
        let key = decodeURI(keyValue[0]);
        let value = keyValue[1];

        if(key.includes('[')){
            let keyJsonString = '{"' + key.replaceAll(/\]\[/ig, '":{"').replaceAll(/\[/ig, '":{"').replaceAll(/\]/ig, '":') + '"' + value + '"' + ''.padEnd((key.match(/\]/g) || []).length, '}') + '}';
            let keyJsonObject = JSON.parse(keyJsonString);

            $.extend(true, partsObject, keyJsonObject);
        }
        else{
            partsObject[key] = value;
        }
    }
    
    return partsObject;
}

tests.js

let textQuery = 'action=view&month_year=2021-09&fk_district_id=&fk_subdistrict_id=&fk_union_id=null&order%5B0%5D%5Bcolumn%5D=1&order%5B0%5D%5Bdir%5D=asc';

console.log(buildJsonFromUrlQuery(textQuery));