insomnia/app/lib/querystring.js

export function getJoiner (url) {
  url = url || '';
  return url.indexOf('?') === -1 ? '?' : '&';
}

export function joinURL (url, qs) {
  if (!qs) { return url; }
  url = url || '';
  return url + getJoiner(url) + qs;
}

export function build (param) {
  // Skip non-name ones
  if (!param.name) { return ''; }

  if (param.value) {
    return encodeURIComponent(param.name) + '=' + encodeURIComponent(param.value);
  } else {
    return encodeURIComponent(param.name);
  }
}

export function buildFromParams (parameters) {
  let items = [];
  for (var i = 0; i < parameters.length; i++) {
    let built = build(parameters[i]);

    if (!built) {
      continue;
    }

    items.push(built);
  }

  return items.join('&');
}