Node.js¶
各个异步 API 优先级：
process.nextTick > promise.then > setImmediate > setTimeout = setInterval
Common errors¶
- Uncaught TypeError: undefined is not a promise
If you get the Uncaught TypeError: undefined is not a promise error in the console, make sure you use new Promise() instead of just Promise()
- UnhandledPromiseRejectionWarning
This means that a promise you called rejected, but there was no catch used to handle the error. Add a catch after the offending then to handle this properly.