cli-helper.js

import readline from 'readline'

function clearScreen() {
  const repeatCount = process.stdout.rows - 2
  const blank = repeatCount > 0 ? '\n'.repeat(repeatCount) : ''
  console.log(blank)
  readline.cursorTo(process.stdout, 0, 0)
  readline.clearScreenDown(process.stdout)
}

function formatter(open, close, replace = open) {
  return input => {
    const string = '' + input
    const index = string.indexOf(close, open.length)
    return ~index ? open + replaceClose(string, close, replace, index) + close : open + string + close
  }
}

function replaceClose(string, close, replace, index) {
  const start = string.substring(0, index) + replace
  const end = string.substring(index + close.length)
  const nextIndex = end.indexOf(close)
  return ~nextIndex ? start + replaceClose(end, close, replace, nextIndex) : start + end
}

function createColors() {
  return {
    reset: s => `\x1b[0m${s}\x1b[0m`,
    bold: formatter('\x1b[1m', '\x1b[22m', '\x1b[22m\x1b[1m'),
    dim: formatter('\x1b[2m', '\x1b[22m', '\x1b[22m\x1b[2m'),
    italic: formatter('\x1b[3m', '\x1b[23m'),
    underline: formatter('\x1b[4m', '\x1b[24m'),
    inverse: formatter('\x1b[7m', '\x1b[27m'),
    hidden: formatter('\x1b[8m', '\x1b[28m'),
    strikethrough: formatter('\x1b[9m', '\x1b[29m'),
    black: formatter('\x1b[30m', '\x1b[39m'),
    red: formatter('\x1b[31m', '\x1b[39m'),
    green: formatter('\x1b[32m', '\x1b[39m'),
    yellow: formatter('\x1b[33m', '\x1b[39m'),
    blue: formatter('\x1b[34m', '\x1b[39m'),
    magenta: formatter('\x1b[35m', '\x1b[39m'),
    cyan: formatter('\x1b[36m', '\x1b[39m'),
    white: formatter('\x1b[37m', '\x1b[39m'),
    gray: formatter('\x1b[90m', '\x1b[39m'),
    bgBlack: formatter('\x1b[40m', '\x1b[49m'),
    bgRed: formatter('\x1b[41m', '\x1b[49m', '\x1b[22m\x1b[1m'),
    bgGreen: formatter('\x1b[42m', '\x1b[49m'),
    bgYellow: formatter('\x1b[43m', '\x1b[49m'),
    bgBlue: formatter('\x1b[44m', '\x1b[49m'),
    bgMagenta: formatter('\x1b[45m', '\x1b[49m'),
    bgCyan: formatter('\x1b[46m', '\x1b[49m'),
    bgWhite: formatter('\x1b[47m', '\x1b[49m'),
  }
}

export { clearScreen, createColors }