express js error handling code example

Example 1: how to handle all error of all router in express

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
    app.use(function (err, req, res, next) {
        res.status(err.status || 500);
        res.render('error.ejs', {
            message: err.message,
            error: err
        });
    });
}

// production error handler
// no stacktraces leaked to user
app.use(function (err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
        message: err.message,
        error: {}
    });
});

Example 2: express error handling

app.use(function (err, req, res, next) {
  console.error(err.stack)
  res.status(500).send('Something broke!')
})

Example 3: error * route

app.get('*', (request, response) => response.status(404).send('This route does not exist'));

Example 4: express generator error handling

app.get('/', function (req, res) {
  throw new Error('BROKEN') // Express will catch this on its own.
})