Function to turn node style functions with callbacks into promises. This is useful when using async/await, since promises can be awaited upon.

awaitable.js

// Function to turn node style functions with callbacks into promises.
// This is useful when using async/await, since promises can be awaited upon.

const callback = (resolve, reject) => (err, res) => err ? reject(err) : resolve(res);
const awaitable = async action => new Promise((resolve, reject) => action(callback(resolve, reject)))
module.exports = awaitable;

// Usage:
//   const fs = require("fs");
//   const awaitable = require("./awaitable");
//   await awaitable(cb => fs.mkdir("new-folder", cb));