@guanghechen/chalk-logger

A simple colorful logger

Usage no npm install needed!

<script type="module">
  import guanghechenChalkLogger from 'https://cdn.skypack.dev/@guanghechen/chalk-logger';
</script>

README

@guanghechen/chalk-logger


chalk-logger is a colorful logger tool based on chalk (so you can use a lot of colors), and can be easily integrated into commander.js (so you can use command line parameters to customized the logger's behavior).

Install

  • npm

    npm install --save @guanghechen/chalk-logger
    
  • yarn

    yarn add @guanghechen/chalk-logger
    

Usage

Options

Name Type Required Default Desc
basename string | null false null see below
mode 'normal' | 'loose' false normal see below
placeholderRegex RegExp false /(?<!\\)\{\}/g string formatter placeholder regex
name string false - name of logger
level Level false Level.INFO verbosity level of the logging output
date boolean false false whether to print the date
title boolean false true whether to print the title
inline boolean false false whether to print each log on one line
colorful boolean false true whether to print log surrounded with color
encoding string false utf-8 see below
filepath string false - see below
write (text: string) => void false process.stdout see below
dateChalk Chalk | Color false chalk.gray color of date string
nameChalk Chalk | Color false chalk.gray color of logger name string

Option Details

  • basename: Base of the logger name, when you change logger name according setName function, the basename will be prefixed of the logger name.

  • mode

    • normal: Print log only
    • loose: Print a newline before and after the log
  • encoding: Specifying the file encoding of filepath, only works if filepath is specified

  • filepath: Log output file

  • write: If filepath is specified, the log is output to filepath by default, otherwise to the process.stdout. You can specify your own write function to customize the output behavior of the log.

Cli Options

  • --log-level <debug|verbose|info|warn|error|fatal>: specify global logger level.

  • --log-name <new logger name>: specify global logger name.

  • --log-mode <'normal' | 'loose'>: specify global logger mode.

  • --log-flag <[no-](date|title|inline|colorful)>: the prefix no- represent negation.

    • date: whether to print date. default value is false
    • title: whether to print title. default value is true
    • inline: each log record output in one line. default value is false.
    • colorful: whether to print with colors. default value is true.
  • --log-output <filepath>: specify the output path (default behavior is output directory to stdout).

    • suggest: set colorful = false and inline = true if you want to output logs into a file.
  • --log-encoding <encoding>: specify the log file's encoding.

Test

Use [@guanghechen/jest-helper][] to spy logger.

import {
  composeStringDesensitizers,
  createFilepathDesensitizer,
  createJsonDesensitizer,
  createLoggerMock,
} from '@guanghechen/jest-helper'

const workspaceRootDir = path.resolve(__dirname, '..')
const desensitize: Desensitizer<unknown[]> = createJsonDesensitizer({
  string: composeStringDesensitizers(
    createFilepathDesensitizer(workspaceRootDir, '<$WORKSPACEgt;'),
    text => text.replace(/\d{4}-\d{2}-\d{2} \d{2}:\d{2}:\d{2}/, '<$Dategt;'),
  ),
}) as Desensitizer<unknown[]>

const logger = new Logger({ name: 'demo', level: DEBUG, date: true })
const loggerMock = createLoggerMock({ logger, desensitize })

// collect data
loggerMock.getIndiscriminateAll()

// reset mock
loggerMock.reset()

// restore mock
loggerMock.restore()

Examples

  • Basic:

    // demo/demo1.ts
    import { ChalkLogger, ERROR } from '@guanghechen/chalk-logger'
    
    const logger = new ChalkLogger({
      name: 'demo',
      level: ERROR,   // the default value is INFO
      date: false,    // the default value is false.
      colorful: true, // the default value is true.
    }, process.argv)
    
    
    logger.debug('A', 'B', 'C')
    logger.verbose('A', 'B', 'C')
    logger.info('a', 'b', 'c')
    logger.warn('X', 'Y', 'Z', { a: 1, b: 2})
    logger.error('x', 'y', 'z', { c: { a: 'hello' }, b: { d: 'world' } })
    logger.fatal('1', '2', '3')
    

    demo1.1.png

  • Custom output format:

    // demo/demo2.ts
    import chalk from 'chalk'
    import { ChalkLogger, ERROR, Level } from '@guanghechen/chalk-logger'
    
    const logger = new ChalkLogger({
      name: 'demo',
      level: ERROR,   // the default value is INFO
      date: false,    // the default value is false.
      colorful: true, // the default value is true.
    }, process.argv)
    
    logger.formatHeader = function (level: Level, date: Date): string {
      let { desc } = level
      let { name } = this
      if( this.flags.colorful ) {
        desc = level.headerChalk.fg(desc)
        if (level.headerChalk.bg != null) desc = level.headerChalk.bg(desc)
        name = chalk.gray(name)
      }
    
      const  header = `${desc} ${name}`
      if( !this.flags.date) return `[${header}]`
    
      let dateString = date.toLocaleTimeString()
      if( this.flags.colorful ) dateString = chalk.gray(dateString)
      return `<${dateString} ${header}>`
    }
    
    logger.debug('A', 'B', 'C')
    logger.verbose('A', 'B', 'C')
    logger.info('a', 'b', 'c')
    logger.warn('X', 'Y', 'Z', { a: 1, b: 2})
    logger.error('x', 'y', 'z', { c: { a: 'hello' }, b: { d: 'world' } })
    logger.fatal('1', '2', '3')
    

    demo2.1.png

  • Custom colors with chalk:

    // demo/demo3.ts
    import chalk from 'chalk'
    import { ChalkLogger, ERROR } from '@guanghechen/chalk-logger'
    
    const logger = new ChalkLogger({
      name: 'demo',
      level: ERROR,     // the default value is INFO
      date: false,      // the default value is false.
      colorful: true,   // the default value is true.
      dateChalk: 'green',
      nameChalk: chalk.cyan.bind(chalk),
    }, process.argv)
    
    logger.debug('A', 'B', 'C')
    logger.verbose('A', 'B', 'C')
    logger.info('a', 'b', 'c')
    logger.warn('X', 'Y', 'Z', { a: 1, b: 2})
    logger.error('x', 'y', 'z', { c: { a: 'hello' }, b: { d: 'world' } })
    logger.fatal('1', '2', '3')
    

    demo3.1.png

  • Output to file

    // demo/demo4.ts
    import path from 'path'
    import chalk from 'chalk'
    import { ChalkLogger, DEBUG } from '@guanghechen/chalk-logger'
    
    const logger = new ChalkLogger({
      name: 'demo',
      level: DEBUG,       // the default value is DEBUG
      date: true,         // the default value is false.
      inline: true,
      colorful: false,    // the default value is true.
      dateChalk: 'green',
      nameChalk: chalk.cyan.bind(chalk),
      filepath: path.resolve(__dirname, 'orz.log'),
      encoding: 'utf-8',
    }, process.argv)
    
    logger.debug('A', 'B', 'C')
    logger.verbose('A', 'B', 'C')
    logger.info('a', 'b', 'c')
    logger.warn('X', 'Y', 'Z', { a: 1, b: 2})
    logger.error('x', 'y', 'z', { c: { a: 'hello' }, b: { d: 'world' } })
    logger.fatal('1', '2', '3')
    

    demo4.1.png

  • With commander.js:

    // demo/demo5.ts
    import chalk from 'chalk'
    import commander from 'Commander'
    import { ChalkLogger, ERROR } from '../src'
    
    const logger = new ChalkLogger({
      name: 'demo',
      level: ERROR,     // the default value is INFO
      date: false,      // the default value is false.
      colorful: true,   // the default value is true.
      dateChalk: 'green',
      nameChalk: chalk.cyan.bind(chalk),
    }, process.argv)
    
    commander
      .version('v1.0.0')
      .arguments('[orz]')
    
    // register logger option to commander
    logger.registerToCommander(commander)
    // or ChalkLogger.registerToCommander(commander)
    
    commander
      .option('-e, --encoding <encoding>', 'specified <filepath>\'s encoding')
      .parse(process.argv)
    
    logger.debug('A', 'B', 'C')
    logger.verbose('A', 'B', 'C')
    logger.info('a', 'b', 'c')
    logger.warn('X', 'Y', 'Z', { a: 1, b: 2})
    logger.error('x', 'y', 'z', { c: { a: 'hello' }, b: { d: 'world' } })
    logger.fatal('1', '2', '3')
    

    demo5.1.png

  • String format:

    // demo/demo6.ts
    import { ChalkLogger, DEBUG } from '../src'
    
    const logger = new ChalkLogger({
      name: 'demo',
      level: DEBUG,
      date: true,
      colorful: true,
      inline: true,
    }, process.argv)
    
    logger.verbose(
      'user({})', 
      { 
        username: 'guanghechen', 
        avatar: 'https://avatars0.githubusercontent.com/u/42513619?s=400&u=d878f4532bb5749979e18f3696b8985b90e9f78b&v=4'
      }
    )
    logger.error(
      'bad argument ({}). error({})', 
      { username: 123 }, 
      new Error('username is invalid')
    )
    
    const logger2 = new ChalkLogger({
      name: 'demo',
      level: DEBUG,
      date: true,
      colorful: true,
      inline: true,
      placeholderRegex: /(?<!\\)\<\>/g  // change placeholder of string format
    }, process.argv)
    
    logger2.verbose(
      'user(<>)', 
      { 
        username: 'guanghechen', 
        avatar: 'https://avatars0.githubusercontent.com/u/42513619?s=400&u=d878f4532bb5749979e18f3696b8985b90e9f78b&v=4'
      }
    )
    logger2.error(
      'bad argument (<>). error({})',
      { username: 123 },
      new Error('username is invalid')
    )
    

    demo6.1.png