errors.js

/* eslint no-undefined: 0 */
'use strict';

const format = require('./format');
const { LEVEL, MESSAGE } = require('triple-beam');

/*
 * function errors (info)
 * If the `message` property of the `info` object is an instance of `Error`,
 * replace the `Error` object its own `message` property.
 *
 * Optionally, the Error's `stack` property can also be appended to the `info` object.
 */
module.exports = format((einfo, { stack }) => {
 if (einfo instanceof Error) {
 const info = Object.assign({}, einfo, {
 level: einfo.level,
 [LEVEL]: einfo[LEVEL] || einfo.level,
 message: einfo.message,
 [MESSAGE]: einfo[MESSAGE] || einfo.message
 });

 if (stack) info.stack = einfo.stack;
 return info;
 }

 if (!(einfo.message instanceof Error)) return einfo;

 // Assign all enumerable properties and the
 // message property from the error provided.
 Object.assign(einfo, einfo.message);
 const err = einfo.message;
 einfo.message = err.message;
 einfo[MESSAGE] = err.message;

 // Assign the stack if requested.
 if (stack) einfo.stack = err.stack;
 return einfo;
});