logger.js

/**
 * @module utils/logger
 */

/**
 * Object from Sentry SDK
 * @see {@link https://docs.sentry.io/clients/javascript/}
 * 
 * Raven (Sentry SDK) is expected to be loaded directly from their CDN.
 * Or you can instead use npm pkg: [raven-js]{@link https://github.com/getsentry/raven-js}
 *
 * Reason for this setup is performance: js bundle are usually quite big in modern websites.
 * If code-splitting is properly implemented, then using npm pkg is a better option.
 *
 * @type {Object}
 */
const Raven = window.Raven;

const LOG_LEVELS = [
  'error',
  'warn',
  'log',
  'info',
  'debug',
  'assert',
  'dir',
  'profile',
  'profileEnd'
];
const __DEV__ = process.env.NODE_ENV !== 'production';
const SENTRY_DSN = process.env.REACT_APP_SENTRY_DSN;

export const init = () => {
  if (SENTRY_DSN && Raven && !__DEV__) {
    Raven.config(SENTRY_DSN).install();
    // if you want to identify user
    // Raven.setUserContext({ id: ''});
  }
};

/**
 * @example
 *   logger('error', new Error('Somehting happened!', {
 *     logger: '',
 *     tags: {},
 *     extra: any
 *   }))
 *
 * @func logger
 * @param {string} level
 * @param {string|Error} message
 * @param {object} additionalData
 */
function logger () {
  const args = Array.prototype.slice.call(arguments);
  // first param can be optionaly the log level
  let level = LOG_LEVELS.every(elem => !(elem === args[0]))
    ? 'info'
    : args.shift();
  if (__DEV__) {
    // check if console[level] is a method of object console <- To be ignored by IE9 and lower
    if (typeof console === 'object' && console[level] && console[level].apply) {
      console[level].apply(console, args);
    }
  }
  // Send log to Sentry
  if (SENTRY_DSN && Raven && !__DEV__) {
    Raven.captureMessage(args[0], Object.assign({ level: level }, args[1]));
  }
}

export default logger;