[Express] Handle Syncronous and Asyncronous Errors in Express

When express App run syncronous code:

app.get("/test", (req, res) => {
  throw new Error("Oh no! The world has ended!");
});

Those code works fine.

 

But when run Asyncronous code:

app.get("/test", async (req, res) => {
  throw new Error("Oh no! The world has ended!");
});

It has problem. 

 

1. Using 'next':

app.get("/test", async (req, res, next) => {
  next(throw new Error("Oh no! The world has ended!"));
});

 

2. Using try/catch:

app.get("/test", async (req, res) => {
    try {
          throw new Error("Oh no! The world has ended!");
    } catch(error) {
        next(error)
    }
});

 

3. Library:  express-async-errors

const express = require("express");
const app = express();
require("express-async-errors");

app.get("/test", async (req, res) => {
  throw new Error("Oh no! The world has ended!");
});

 

4. Custom middleware:

const { errorHandling } = require("./utils/error");

app.get("/test", async (req, res) => {
  throw new Error("Oh no! The world has ended!");
});

app.use(errorHandling); // keep it as last step

app.listen(3001, function () {
  console.log("Server started.");
});

function errorHandling(error, req, res, next) {
  if (res.headersSent) {
    next(error);
  } else {
    res.status(500);
    res.json({
      message: error.message,
      ...(process.env.NODE_ENV === "production"
        ? null
        : { stack: error.stack }),
    });
  }
}

module.exports = { errorHandling };