Simple methods to send javascript obejects to slack webhook

simple_slack_vanilla.js

let js_obj = {a:'test_track', b:2};

function __getSlackFields(data){
var fields = [];
Object.keys(data).map((key) => {
    fields.push({ title: key, value: data[key], short: true });
    return key;
  });
return fields;
}
function __postMessageToSlack(webhook_url, payload){
    var xhr = new XMLHttpRequest()
    xhr.open('POST', webhook_url, false);
    xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    xhr.send(payload);
}

payload = JSON.stringify({'attachments': [{'fields': __getSlackFields(js_obj)}]});

__postMessageToSlack($$YOUR_SLACK_WEBHOOK$$, payload);