index.js

const valueParser = require('postcss-values-parser');
const colors = require('color-name');

const {
  convertingHEXColor,
  convertingRGBColor,
  convertingHSLColor,
  convertingKeywordColor,
} = require('./src/converts');
const {
  HEX_COLOR,
  RGB_COLOR,
  HSL_COLOR,
  KEYWORD_COLOR,
} = require('./src/constants');

const colorNames = Object.keys(colors);
const colorFormats = [HEX_COLOR, RGB_COLOR, HSL_COLOR, KEYWORD_COLOR];

const propsWithColorRegExp = /(background|border|shadow|color|fill|outline|@|--|\$)/;
const ignoredValuesRegExp = /(url)/;
const specValuesInParamsRegExp = /(\$|calc|var)/;

const defaultOptions = {
  outputColorFormat: '',
  alwaysAlpha: false,
  ignore: [],
};

module.exports = (options = {}) => {
  const currentOptions = {
    ...defaultOptions,
    ...options,
  };

  if (!currentOptions.outputColorFormat) {
    throw new Error(`'outputColorFormat' option is undefined.`)
  }

  if (!colorFormats.includes(currentOptions.outputColorFormat)) {
    throw new Error(`The specified value of 'outputColorFormat' is not contained in [${colorFormats.join()}].`)
  }

  return {
    postcssPlugin: 'postcss-color-converter',
    Declaration (decl) {
      if (
        decl.prop && propsWithColorRegExp.test(decl.prop) && decl.value && !ignoredValuesRegExp.test(decl.value)
      ) {
        let valueObj = valueParser.parse(decl.value, { ignoreUnknownWords: true });

        valueObj.walk(node => {
          if (node.isColor) {
            if (
              !currentOptions.ignore.includes(HEX_COLOR) &&
              currentOptions.outputColorFormat !== HEX_COLOR &&
              node.isHex
            ) {
              node = convertingHEXColor(node, currentOptions);
            } else if (
              (
                !currentOptions.ignore.includes(RGB_COLOR) &&
                (
                  currentOptions.alwaysAlpha ||
                  currentOptions.outputColorFormat !== RGB_COLOR
                )
              ) &&
              (node.name === 'rgb' || node.name === 'rgba') &&
              !specValuesInParamsRegExp.test(node.params)

            ) {
              node = convertingRGBColor(node, currentOptions);
            } else if (
              (
                !currentOptions.ignore.includes(HSL_COLOR) &&
                (
                  currentOptions.alwaysAlpha ||
                  currentOptions.outputColorFormat !== HSL_COLOR
                )
              ) &&
              (node.name === 'hsl' || node.name === 'hsla') &&
              !specValuesInParamsRegExp.test(node.params)
            ) {
              node = convertingHSLColor(node, currentOptions);
            } else if (
              !currentOptions.ignore.includes(KEYWORD_COLOR) &&
              colorNames.includes(node.value)
            ) {
              node = convertingKeywordColor(node, currentOptions);
            }
          }
        });

        decl.value = valueObj.toString();
      }
    }
  };
};

module.exports.postcss = true;