ES6 fetch syntactic sugar: handling common fetch usage with json content type, same headers, and stringified body

ES6-request-json.js

/*
  fetch is awesome, there's no question about it.
  But aren't you tired of:
   - Writing your `res => res.json()` handler
   - Having to stringify your body 
   - Signin your request with the same headers (```{'Content-Type': json, Authorization: 'JWT ...'}```)
   - Inconsistently handling the response status code and not reject promise when relevant.
   
  Usage:
  request('http://yourawesome.api.com').then(console.log).catch(console.error);
  request('http://yourawesome.api.com', {
    method: 'PUT',
    body: { coworkingAt: 'fishburners' },
  })
  .then(console.log)
  .catch(console.error);
*/

const defaultHeaders = { 'Content-Type': 'application/json' };
const RESOLVE_STATUS_CODES = [200];

const request = (url, options = {}) => {
  const params = Object.assign({}, options, {
    headers: Object.assign(defaultHeaders, options.headers || {})
  });
  if (options.body && typeof options.body !== 'string') {
    params.body = JSON.stringify(options.body);
  }
  return fetch(url, params)
  .then(res => {
    const verb = RESOLVE_STATUS_CODES.indexOf(res.status) === -1 ? 'reject' : 'resolve';
    return res.json()
    .then(payload => Promise[verb](payload));
  });
};

export default request;

Edit: handling responses status' code and reject promise accordingly.