build-list.js

'use strict';
const fs = require('fs');
const episodes = require('./content/episodes.json');
const obj = [];

// loop through the episode list and construct a new object
for(let ep in episodes) {
    const episode = episodes[ep].episode;
    const title = episodes[ep].title;
    const description = episodes[ep].description;
    const published = episodes[ep].published;
    if(episode !== undefined) {
        // only use keys from the original JSON needed
        const details = {
            episode: episode,
            title: title,
            description: description,
            published: published
        };

        // add details to object
        obj.push(details);
    }
}

// create episode-list JSON file
fs.writeFile('./content/episode-list.json', JSON.stringify(obj), function (err) {
    return err ? console.log(err) : null;
});