error-handler.js

/**
 * Copyright 2015 IBM Corp. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
 /* eslint no-unused-vars: "off" */


module.exports = function (app) {
  // catch 404 and forward to error handler
  app.use((req, res, next) => {
    const err = new Error('Not Found');
    err.code = 404;
    err.message = 'Not Found';
    next(err);
  });

  // error handler
  app.use((err, req, res, next) => {
    const error = {
      // node.js will throw if the http status code is invalid
      code: typeof err.code === 'number' && err.code >= 100 && err.code <= 999 ? err.code : 500,
      error: err.error || err.message,
    };
    res.status(error.code).json(error);
  });
};