06 Node Js Error Handing

Review

  1. 2023-10-10 22:36
  2. 2024-10-03

一、Introduction #

Error handling is a way to find bugs and solve them as quickly as humanly possible. The errors in Node.js can be either operation or programmer errors.

有两种错误

  • 编程错误：程序员写出的错误（语法错误、引用错误、类型错误）
  • 业务错误：外部因素导致服务不能正常运行（超时、服务端异常、输入错误）

Error handling techniques #

  1. throw
  2. try…catch blocks
  3. Callbacks
  4. Promises or Async/await
  5. Event emitters(events)
  6. Middleware
  7. unhandledRejection, uncaughtException, uncaughtExceptionMonitor
process.on('uncaughtException', function(err) {
  console.log('Caught exception: ' + err);
});
process.on('unhandledRejection', (err) => {

})

Common exit codes in Node.js:

  • 0: The program exited normally.
  • 1: A generic error occurred.
  • 12: The program received a SIGTERM signal (termination signal).
  • 13: The program received a SIGKILL signal (kill signal).
  • 14: The program received a SIGALRM signal (alarm signal).
  • 15: The program received a SIGTERM signal and had a timeout.

Other possible exit codes:

  • 2: A syntax error occurred.
  • 3: A runtime error occurred.
  • 4: A system error occurred.
  • 5: A disk full error occurred.
  • 6: An unknown error occurred.

Reference #