Function promisify

systemvm/agent/noVNC/utils/convert.js:23–33

(original)

// util.promisify requires Node.js 8.x, so we have our own
function promisify(original) {
    return function promiseWrap() {
        const args = Array.prototype.slice.call(arguments);
        return new Promise((resolve, reject) => {
            original.apply(this, args.concat((err, value) => {
                if (err) return reject(err);
                resolve(value);
            }));
        });
    };
}

const writeFile = promisify(fs.writeFile);