ilog

light-weight, smart and pure log module.

Installation

npm install ilog

API

const ilog = require('ilog')

or

import { ilog } from 'ilog'

ilog([arguments]) [no level]

ilog.log([arguments]) [no level]

Format one or more arguments to string and write it to ilog._stdout.

Example:

ilog('hello', {a: 1, b: 2}, [1, 2, 3])
// Output: hello { a: 1, b: 2 } [ 1, 2, 3 ]

Source Code:

function ilog () {
  if (arguments.length) {
    ilog._stdout.write(ilog._assembleLog(util.format.apply(null, arguments)))
  }
}

ilog.emerg(error) [level 0]

ilog.alert(error) [level 1]

ilog.crit(error) [level 2]

ilog.error(error) [level 3]

ilog.warning(error) [level 4]

Format the error object to error string and write it to ilog._stderr.

Example:

ilog.error()
// Nothing

ilog.error(null)
// Nothing

ilog.level = 3
ilog.error(new Error('test error'))
// Output: [2015-11-02T14:07:52.368Z] ERROR {"message":"test error","name":"Error","stack":"Error: test error\n ..."}

ilog.error('test error 2')
// Output: [2015-11-02T14:07:52.368Z] ERROR {"name":"Error","message":"test error 2"}

ilog.warning(new Error('test warning'))
// Nothing, because log level is lower than warning level[level 4]

Source Code:

// ilog.emerg, ilog.alert, ilog.crit, ilog.error, ilog.warning
levels.slice(0, 5).map(function (level, index) {
  ilog[level.toLowerCase()] = function (error) {
    if (error != null && index <= ilog.level) {
      error = ilog._stringify(ilog._errorify(error))
      ilog._stderr.write(ilog._assembleLog(error, level, ilog._time(new Date())))
    }
  }
})

ilog.notice(message) [level 5]

ilog.info(message) [level 6]

Format the message object to string and write it to ilog._stdout.

Example:

ilog.info()
// Nothing

ilog.info(null)
// Nothing

ilog.notice({a: 1, b: 2})
// Output: [2015-11-02T14:11:44.588Z] NOTICE {"a":1,"b":2}

ilog.info('{a: 1, b: 2}')
// [2015-11-05T07:21:36.916Z] INFO "{a: 1, b: 2}"

Source Code:

// ilog.notice, ilog.info
levels.slice(5, 7).map(function (level, index) {
  index += 5
  ilog[level.toLowerCase()] = function (message) {
    if (message != null && index <= ilog.level) {
      message = ilog._stringify(message)
      ilog._stdout.write(ilog._assembleLog(message, level, ilog._time(new Date())))
    }
  }
})

ilog.debug(message[, message, ...]) [level 7]

Format one or more arguments to string and write it to ilog._stdout. if only one argument, use JSON.stringify, else use util.format

Example:

ilog.debug({a: 1, b: 2})
// [2015-11-05T07:24:55.551Z] DEBUG {"a":1,"b":2}

ilog.debug('{a: 1, b: 2}')
// [2015-11-05T07:25:20.103Z] DEBUG "{a: 1, b: 2}"

ilog.debug(null, {a: 1, b: 2}, null, [1, 2, 3])
// [2015-11-05T07:26:03.119Z] DEBUG null { a: 1, b: 2 } null [ 1, 2, 3 ]

ilog.debug('Hello, %s', [1, 2, 3], {a: 1, b: 2})
// [2015-11-05T07:27:02.020Z] DEBUG Hello, 1,2,3 { a: 1, b: 2 }

Source Code:

// ilog.notice, ilog.info
ilog.debug = function () {
  if (arguments.length && ilog.level >= 7) {
    let messages = arguments.length === 1
      ? ilog._stringify(arguments[0]) : util.format.apply(null, arguments)
    ilog._stdout.write(ilog._assembleLog(messages, 'DEBUG', ilog._time(new Date())))
  }
}

ilog.auto(error[, message]) [level error, info, debug]

A error (error instanceof Error) will log to ilog.error. A message will log to ilog.info. One more message will log to ilog.debug.

Example:

ilog.auto(new Error('some error'), {a: 1, b: 2})
// Output: [2015-11-02T14:13:24.409Z] ERROR {"message":"some error","name":"Error","stack":"Error: some error\n ..."}
ilog.auto(null, {a: 1, b: 2})
// Output: [2015-11-02T14:14:18.483Z] INFO {"a":1,"b":2}
ilog.auto({a: 1, b: 2})
// Output: [2015-11-02T14:14:53.412Z] INFO {"a":1,"b":2}
ilog.auto(null, {a: 1, b: 2}, [1, 2, 3])
// Output: [2015-11-02T14:15:16.933Z] DEBUG { a: 1, b: 2 } [ 1, 2, 3 ]
ilog.auto({a: 1, b: 2}, [1, 2, 3])
// Output: [2015-11-02T14:15:41.398Z] DEBUG { a: 1, b: 2 } [ 1, 2, 3 ]

Source Code:

ilog.auto = function (error) {
  if (error instanceof Error) return ilog.error(error)
  let args = slice.call(arguments, +(error == null))
  if (args.length === 1) ilog.info(args[0])
  else if (args.length > 1) ilog.debug.apply(null, args)
}

ilog.setLevel(level)

Set the log level, any value in ilog.levels will be fine, default to DEBUG

ilog.levels

All log levels: ['EMERG', 'ALERT', 'CRIT', 'ERR', 'WARNING', 'NOTICE', 'INFO', 'DEBUG'].

ilog._stdout

Set the log standard out stream, default to process.stdout

ilog._stderr

Set the log error out stream, default to process.stderr

ilog._time

Set the time format function, default to:

ilog._time = function (time) {
  return '[' + time.toISOString() + ']'
}

ilog._stringify

Set the object format function, default to:

ilog._stringify = function (obj) {
  try {
    return JSON.stringify(obj)
  } catch (e) {
    return util.format(obj)
  }
}

ilog._assembleLog

Set the log format function, default to:

ilog._assembleLog = function (log, level, time) {
  log = log + '\n'
  if (level) log = level + ' ' + log
  if (time) log = time + ' ' + log
  return log
}

ilog._errorify

Set the error object format function, default to:

ilog._errorify = function (error) {
  return new Errorify(error)
}