Express middleware error handling with ease

app.js

// catch 404 and forward to error handler
app.use((req, res, next) => {
  res.status(404).json({ message: 'API not found' });
  next();
});

// error handler, send stacktrace only during development
app.use((err, req, res, next) => {
  if (res.headersSent) {
    return next(err);
  }
  const status = err.status ? err.status : httpStatus.INTERNAL_SERVER_ERROR;
  const sendAsOutput = { message: err.message };
  if (config.env === 'development') {
    sendAsOutput.error = err;
  }
  return res.status(status).json(sendAsOutput);
});

error.js

// helper file for generating error in next()
const genError = (message, status, error) => ({
  error,
  message,
  status,
});

module.exports = { genError };