acho/lib/Format.js

The Hackable Log

'use strict'

const { createFormatter } = require('fmt-obj')
const slice = require('sliced')

const {
  getColor,
  colorize,
  isString,
  isEmpty,
  isSymbol,
  isObject,
  isBuffer,
  isError,
  isDate,
  isFalsy,
  isArray,
  hasWhiteSpace
} = require('./Util')
const CONST = require('./Constants')

const ESCAPE_REGEX = /%{2,2}/g
const TYPE_REGEX = /(%?)(%([Jjds]))/g

function prettyObj (obj, color, opts) {
  const lineColor = getColor(CONST.LINE_COLOR)
  const { offset, depth } = opts

  const fmtObj = createFormatter({
    offset,
    formatter: {
      punctuation: lineColor,
      annotation: lineColor,
      property: getColor(color),
      literal: lineColor,
      number: lineColor,
      string: lineColor
    }
  })

  return fmtObj(obj, depth)
}

function serialize (obj, color, key) {
  // symbols cannot be directly casted to strings
  if (isSymbol(key)) key = key.toString()
  if (isSymbol(obj)) obj = obj.toString()
  if (isFalsy(obj)) obj = JSON.stringify(obj)
  if (!isObject(obj)) {
    if (key && isString(obj) && hasWhiteSpace(obj)) obj = `'${obj}'`
    return key ? `${key}=${obj}` : obj
  }

  if (isBuffer(obj)) {
    obj = obj.toString('base64')
    return key ? `${key}=${obj}` : obj
  }

  if (isError(obj)) return obj.message || obj

  let msg = ''
  const keys = Object.keys(obj)
  const { length } = keys
  let i = 0
  while (i < length) {
    key = keys[i]
    const value = obj[key]

    if (isArray(value)) {
      msg += key + '=['
      let j = 0
      const l = value.length
      while (j < l) {
        msg += serialize(value[j], color)
        if (j < l - 1) {
          msg += ' '
        }
        j++
      }
      msg += ']'
    } else if (isDate(value)) {
      msg += key + '=' + value
    } else {
      msg += serialize(value, color, colorize(color, key))
    }
    if (i < length - 1) {
      msg += ' '
    }
    i++
  }
  return msg
}

const createFormat = opts =>
  function format (messages) {
    const args = slice(arguments, 1)
    const color = args.pop()

    if (!isEmpty(args)) {
      messages = messages.replace(TYPE_REGEX, function (
        match,
        escaped,
        ptn,
        flag
      ) {
        let arg = args.shift()
        switch (flag) {
          case 's':
            arg = colorize(color, String(arg))
            break
          case 'd':
            arg = colorize(color, Number(arg))
            break
          case 'j':
            arg = serialize(arg, color)
            break
          case 'J':
            arg = prettyObj(arg, color, opts)
            break
        }
        if (!escaped) return arg
        args.unshift(arg)
        return match
      })
      if (!isEmpty(args)) {
        for (const arg of args) messages += ` ${serialize(arg, color)}`
      }
    }

    if (messages.replace != null) messages = messages.replace(ESCAPE_REGEX, '%')
    return serialize(messages, color)
  }

module.exports = createFormat