@dcloudio/uni-debugger/src/util/logger.js

uni-app debugger

const chalk = require('chalk')
const EventEmitter = require('events').EventEmitter

const events = new EventEmitter()
const LOGLEVELS = ['verbose', 'log', 'info', 'warn', 'error', 'success']

// global var
const LOGLEVEL = {
  VERBOSE: 'verbose',
  LOG: 'log',
  WARN: 'warn',
  INFO: 'info',
  ERROR: 'error',
  SUCCESS: 'success'
}

const SEVERITY = {
  verbose: 1000,
  log: 2000,
  warn: 3000,
  info: 3000,
  error: 5000,
  success: 10000
}

const LOGCOLOR = {
  verbose: 'grey',
  log: 'white',
  warn: 'yellow',
  info: 'white',
  error: 'red',
  success: 'green'
}

let DEFAULT_LOGLEVEL = LOGLEVEL.LOG

const formatError = (error, isVerbose) => {
  let message = ''
  if (error instanceof Error) {
    if (isVerbose) {
      message = error.stack
    }
    else {
      message = error
    }
  }
  else {
    // Plain text error message
    message = error.stack
  }
  if (
    typeof message === 'string' &&
    message.toUpperCase().indexOf('ERROR:') !== 0
  ) {
    // Needed for backward compatibility with external tools
    message = 'Error: ' + message
  }
  return message
}

const fill = num => {
  return num > 9 ? num : `0${num}`
}
const log = loglevel => {
  return message => {
    const isVerbose = DEFAULT_LOGLEVEL === LOGLEVEL.VERBOSE
    if (
      !SEVERITY[DEFAULT_LOGLEVEL] ||
      SEVERITY[DEFAULT_LOGLEVEL] > SEVERITY[loglevel]
    ) {
      // return instance to allow to chain calls
      return
    }
    if (message instanceof Error || (isVerbose && loglevel === 'error')) {
      message = formatError(message, isVerbose)
    }
    const color = LOGCOLOR[loglevel]
    let time
    let prefix
    let sep
    if (SEVERITY[loglevel] >= SEVERITY[LOGLEVEL.INFO]) {
      time = new Date()
      prefix = chalk.gray(
        `${fill(time.getHours())}:${fill(time.getMinutes())}:${fill(
          time.getSeconds()
        )}`
      )
      sep = ':'
      console.log(chalk.grey(prefix), sep, chalk[color](message))
    }
    else {
      console.log(chalk[color](message))
    }
  }
}

const subscribe = event => {
  if (!(event instanceof EventEmitter)) {
    throw new Error(
      'Subscribe method only accepts an EventEmitter instance as argument'
    )
  }
  event
    .on('verbose', log('verbose'))
    .on('log', log('log'))
    .on('info', log('info'))
    .on('warn', log('warn'))
    .on('error', log('error'))
    .on('success', log('success'))

  return event
}

const setLevel = logLevel => {
  DEFAULT_LOGLEVEL = logLevel
}

module.exports = {
  setLevel,
  subscribe,
  verbose: log('verbose'),
  log: log('log'),
  info: log('info'),
  warn: log('warn'),
  error: log('error'),
  success: log('success'),
  events,
  LOGLEVELS
}