fetch.js

import _fetch from 'isomorphic-fetch'
import checkStatus from '../src/utils/check-status'
import parseBody from '../src/utils/parse-body'
import jsonFile from 'jsonfile'

let cache = {}
const cachePath = __dirname + '/cache.json'

export default function fetch (url, ignoreCache = false) {
  if (!ignoreCache) {
    try {
      cache = jsonFile.readFileSync(cachePath)
      if (cache[url]) return Promise.resolve(cache[url])
    } catch (e) {
      cache = {}
    }
  }

  return _fetch(url).then(checkStatus).then(parseBody)
    .then(response => {
      if (!ignoreCache) {
        cache[url] = response
        jsonFile.writeFileSync(cachePath, cache)
      }

      return response
    })
}