From Callback Hell to Callback HeavenRemember the time when a lot of JavaScript code looked like this? router.put('/some-url', (req, res) => { fs.readFile(filePath(req), (err, file) => { if (err) res.status(500).send() else { parse(file, (err, parsed) => { if (err) res.status(500).send() else db.insert(parsed, err => { if (err) res.status(500).send() else res.status(200).send() }) }) } }) }) For those fortunate enough to not remember
