Generate JSON string of environment variables of a wercker pipeline

envToJSON.js

var envVar = {};
var tr = Array.from(
    document.querySelectorAll("table")[0].querySelectorAll('tbody')[0].querySelectorAll('tr'));
        tr.map((el)=>{
            var tmp = [];
            tmp[el.querySelectorAll('.envvarItem_key')[0].querySelectorAll('input')[0].value] = el.querySelectorAll('td')[1].querySelectorAll('.envvarItem_value')[0].querySelectorAll('.envvarItem_value_container')[0].querySelectorAll('textarea')[0].value;
            envVar = Object.assign(envVar, tmp);
        }
    );
    
console.log(JSON.stringify(envVar));