Node.js 最佳實作¶

Referrer from express.js best practice.

In most cases, these are still useful in different frameworks or applications.

Do In Code¶

Compression: proxy > app.use(compression())
Asynchronous (async.) >> Synchronous (sync.)
- The only reason to use sync. function is the time to start up server.
- 唯一有理由使用同步函數的時機是在最初啟動之時
Static files: proxy > serve-static > res.sendFile()
Console is sync! Always use async or use sync only in development.
- Debugging: debug >> console
- Application: Winston / Bunyan >> console
Handle Error ( Important!, Detailed in next section )
- Try-catch
- Promise

Handle Error¶

Try-catch is synchronous.
Express catch all sync. error in default (v.5 catch Promise as well)

What will log?¶

const callback = async () => {
    console.log("do another thing");
    throw new Error("foo");
    console.log("do more thing");
};

const method = async () => {
    console.log("do first thing");
    callback();
    console.log("do second thing");
};

const main = async () => {
    try {
        method();
    } catch (err) {
        console.log("fire try-catch!");
    }

    console.log("finish project!");
};

Result¶

do first  thing
do another thing
do second thing
finish project!
UnhandledPromiseRejectionWarning: Error: foo
... (error stack)

why?¶

callback invoked some time later after method (do another thing).
happened exception! wait to finish other synchronous processes (do second thing).
finish try-catch block.
final run (finish project!).
Fire the asynchronous exception!

Category¶

Operational Errors
- The errors you are/can except.
- Log, Show, Retry/Abort.
Programmer Errors
- The best way to recover from programmer errors is to crash immediately
- Try debug your program rather than handle it.

Do In Configuration¶

env.NODE_ENV='production';
Rebuild after error, use helpers or init system ¹ ²
Multi-threads ³ ⁴
Caching ⁵ ⁶
Reverse-Proxy ⁷ ⁸