ads-repository.js

const jsonfile = require('jsonfile');
const _ = require('lodash');

const previousAdsFilename = './previous-ads.json';
const previousAds = (jsonfile.readFileSync(previousAdsFilename) || {}).ads || [];

module.exports = {
  wasAlreadySent: (id) => _.includes(previousAds, id),
  updateSent: (id) => previousAds.push(id),
  flush: () => jsonfile.writeFile(previousAdsFilename, { ads: previousAds })
};