error-handling-with-express.js

var express = require("express");
var path = require("path");

var app = express();

var filePath = path.join(__dirname, "celine.jpg");

app.use(function(req, res, next){
    res.sendFile(filePath, function(err){
        if(err){
            next(new Error("Error sending the file!"));
        } 
    });
});

app.use(function(err, req, res, next){
    console.error(err);
    next(err);
});

app.use(function(err, req, res, next){
    res.status(500);
    res.send("Internal server error.");
});

app.listen(8080, function(){
    console.log("App started on port 8080");
})