index.js

'use strict';

const isObject = val => val !== null && typeof val === 'object' && !Array.isArray(val);

/* eslint-disable no-control-regex */
// this is a modified version of https://github.com/chalk/ansi-regex (MIT License)
const ANSI_REGEX = /[\u001b\u009b][[\]#;?()]*(?:(?:(?:[^\W_]*;?[^\W_]*)\u0007)|(?:(?:[0-9]{1,4}(;[0-9]{0,4})*)?[~0-9=<>cf-nqrtyA-PRZ]))/g;

const hasColor = () => {
  if (typeof process !== 'undefined') {
    return process.env.FORCE_COLOR !== '0';
  }
  return false;
};

const create = () => {
  const colors = {
    enabled: hasColor(),
    visible: true,
    styles: {},
    keys: {}
  };

  const ansi = style => {
    let open = style.open = `\u001b[${style.codes[0]}m`;
    let close = style.close = `\u001b[${style.codes[1]}m`;
    let regex = style.regex = new RegExp(`\\u001b\\[${style.codes[1]}m`, 'g');
    style.wrap = (input, newline) => {
      if (input.includes(close)) input = input.replace(regex, close + open);
      let output = open + input + close;
      // see https://github.com/chalk/chalk/pull/92, thanks to the
      // chalk contributors for this fix. However, we've confirmed that
      // this issue is also present in Windows terminals
      return newline ? output.replace(/\r*\n/g, `${close}$&${open}`) : output;
    };
    return style;
  };

  const wrap = (style, input, newline) => {
    return typeof style === 'function' ? style(input) : style.wrap(input, newline);
  };

  const style = (input, stack) => {
    if (input === '' || input == null) return '';
    if (colors.enabled === false) return input;
    if (colors.visible === false) return '';
    let str = '' + input;
    let nl = str.includes('\n');
    let n = stack.length;
    if (n > 0 && stack.includes('unstyle')) {
      stack = [...new Set(['unstyle', ...stack])].reverse();
    }
    while (n-- > 0) str = wrap(colors.styles[stack[n]], str, nl);
    return str;
  };

  const define = (name, codes, type) => {
    colors.styles[name] = ansi({ name, codes });
    let keys = colors.keys[type] || (colors.keys[type] = []);
    keys.push(name);

    Reflect.defineProperty(colors, name, {
      configurable: true,
      enumerable: true,
      set(value) {
        colors.alias(name, value);
      },
      get() {
        let color = input => style(input, color.stack);
        Reflect.setPrototypeOf(color, colors);
        color.stack = this.stack ? this.stack.concat(name) : [name];
        return color;
      }
    });
  };

  define('reset', [0, 0], 'modifier');
  define('bold', [1, 22], 'modifier');
  define('dim', [2, 22], 'modifier');
  define('italic', [3, 23], 'modifier');
  define('underline', [4, 24], 'modifier');
  define('inverse', [7, 27], 'modifier');
  define('hidden', [8, 28], 'modifier');
  define('strikethrough', [9, 29], 'modifier');

  define('black', [30, 39], 'color');
  define('red', [31, 39], 'color');
  define('green', [32, 39], 'color');
  define('yellow', [33, 39], 'color');
  define('blue', [34, 39], 'color');
  define('magenta', [35, 39], 'color');
  define('cyan', [36, 39], 'color');
  define('white', [37, 39], 'color');
  define('gray', [90, 39], 'color');
  define('grey', [90, 39], 'color');

  define('bgBlack', [40, 49], 'bg');
  define('bgRed', [41, 49], 'bg');
  define('bgGreen', [42, 49], 'bg');
  define('bgYellow', [43, 49], 'bg');
  define('bgBlue', [44, 49], 'bg');
  define('bgMagenta', [45, 49], 'bg');
  define('bgCyan', [46, 49], 'bg');
  define('bgWhite', [47, 49], 'bg');

  define('blackBright', [90, 39], 'bright');
  define('redBright', [91, 39], 'bright');
  define('greenBright', [92, 39], 'bright');
  define('yellowBright', [93, 39], 'bright');
  define('blueBright', [94, 39], 'bright');
  define('magentaBright', [95, 39], 'bright');
  define('cyanBright', [96, 39], 'bright');
  define('whiteBright', [97, 39], 'bright');

  define('bgBlackBright', [100, 49], 'bgBright');
  define('bgRedBright', [101, 49], 'bgBright');
  define('bgGreenBright', [102, 49], 'bgBright');
  define('bgYellowBright', [103, 49], 'bgBright');
  define('bgBlueBright', [104, 49], 'bgBright');
  define('bgMagentaBright', [105, 49], 'bgBright');
  define('bgCyanBright', [106, 49], 'bgBright');
  define('bgWhiteBright', [107, 49], 'bgBright');

  colors.ansiRegex = ANSI_REGEX;
  colors.hasColor = colors.hasAnsi = str => {
    colors.ansiRegex.lastIndex = 0;
    return typeof str === 'string' && str !== '' && colors.ansiRegex.test(str);
  };

  colors.alias = (name, color) => {
    let fn = typeof color === 'string' ? colors[color] : color;

    if (typeof fn !== 'function') {
      throw new TypeError('Expected alias to be the name of an existing color (string) or a function');
    }

    if (!fn.stack) {
      Reflect.defineProperty(fn, 'name', { value: name });
      colors.styles[name] = fn;
      fn.stack = [name];
    }

    Reflect.defineProperty(colors, name, {
      configurable: true,
      enumerable: true,
      set(value) {
        colors.alias(name, value);
      },
      get() {
        let color = input => style(input, color.stack);
        Reflect.setPrototypeOf(color, colors);
        color.stack = this.stack ? this.stack.concat(fn.stack) : fn.stack;
        return color;
      }
    });
  };

  colors.theme = custom => {
    if (!isObject(custom)) throw new TypeError('Expected theme to be an object');
    for (let name of Object.keys(custom)) {
      colors.alias(name, custom[name]);
    }
    return colors;
  };

  colors.alias('unstyle', str => {
    if (typeof str === 'string' && str !== '') {
      colors.ansiRegex.lastIndex = 0;
      return str.replace(colors.ansiRegex, '');
    }
    return '';
  });

  colors.alias('noop', str => str);
  colors.none = colors.clear = colors.noop;

  colors.stripColor = colors.unstyle;
  colors.symbols = require('./symbols');
  colors.define = define;
  return colors;
};

module.exports = create();
module.exports.create = create;