simple.js

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

const format = require('./format');
const { MESSAGE } = require('triple-beam');
const jsonStringify = require('safe-stable-stringify');

/*
 * function simple (info)
 * Returns a new instance of the simple format TransformStream
 * which writes a simple representation of logs.
 *
 *    const { level, message, splat, ...rest } = info;
 *
 *    ${level}: ${message}                            if rest is empty
 *    ${level}: ${message} ${JSON.stringify(rest)}    otherwise
 */
module.exports = format(info => {
  const stringifiedRest = jsonStringify(Object.assign({}, info, {
    level: undefined,
    message: undefined,
    splat: undefined
  }));

  const padding = info.padding && info.padding[info.level] || '';
  if (stringifiedRest !== '{}') {
    info[MESSAGE] = `${info.level}:${padding} ${info.message} ${stringifiedRest}`;
  } else {
    info[MESSAGE] = `${info.level}:${padding} ${info.message}`;
  }

  return info;
});