custom error class (uses lodash)

error.js

'use strict';

import lodash as _ from 'lodash';

/*
  options can be:
   - name: The name property represents a name for the type of error.

  See this for throwing a custom error: 
   - https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error/name
*/

class WHError extends Error {
  constructor (message = "Error without a message",
               inner = null,
               { name: "WHError" }) {

    this.name = name;
    this.message = message;

    if (inner) {
      this.innerError = inner;
    }

    this.toString = formatErrorMessage;
  }
}

function formatErrorMessage () {
  let err = this;
  let messages = [ constructMessage(err) ];

  while (err.innerError) {
    err = err.innerError;
    messages.push( constructMessage(err) );
  }

  return _.chain(messages)
    .reverse(messages)
    .join(' -> ')
    .value();
}

function constructMessage ({ name, message }) {
  return `${name}: ${message}`;
}

export default WHError;