http-service.js

import {isJSON} from '../utils/is-json';
import request from './superagent';

export async function({method = 'GET', url}) {
  method = method.toUpperCase();
  const methods = ['GET', 'POST'];
  let [foundMethod] = methods.filter(m => method === m);
  
  if (!foundMethod) {
    throw new Error('you specified an unknown method')
  }
  
  let response
  try {
    response = await superagent(method, url);
  } catch (err) {
    return Promise.reject(err); //async function will automatically wrap this in a returned promise
  }

  return isJson(response) ? response : Promise.reject('Bad JSON :-((')
}

superagent.js

import superagent from 'superagent';
import superagentPromise from 'superagent-promise';

const agent = superagentPromise(superagent, Promise);

export default agent;