isHSL.js

import assertString from './util/assertString';

const hslComma = /^hsla?\(((\+|\-)?([0-9]+(\.[0-9]+)?(e(\+|\-)?[0-9]+)?|\.[0-9]+(e(\+|\-)?[0-9]+)?))(deg|grad|rad|turn)?(,(\+|\-)?([0-9]+(\.[0-9]+)?(e(\+|\-)?[0-9]+)?|\.[0-9]+(e(\+|\-)?[0-9]+)?)%){2}(,((\+|\-)?([0-9]+(\.[0-9]+)?(e(\+|\-)?[0-9]+)?|\.[0-9]+(e(\+|\-)?[0-9]+)?)%?))?\)$/i;
const hslSpace = /^hsla?\(((\+|\-)?([0-9]+(\.[0-9]+)?(e(\+|\-)?[0-9]+)?|\.[0-9]+(e(\+|\-)?[0-9]+)?))(deg|grad|rad|turn)?(\s(\+|\-)?([0-9]+(\.[0-9]+)?(e(\+|\-)?[0-9]+)?|\.[0-9]+(e(\+|\-)?[0-9]+)?)%){2}\s?(\/\s((\+|\-)?([0-9]+(\.[0-9]+)?(e(\+|\-)?[0-9]+)?|\.[0-9]+(e(\+|\-)?[0-9]+)?)%?)\s?)?\)$/i;

export default function isHSL(str) {
  assertString(str);

  // Strip duplicate spaces before calling the validation regex (See  #1598 for more info)
  const strippedStr = str.replace(/\s+/g, ' ').replace(/\s?(hsla?\(|\)|,)\s?/ig, '$1');

  if (strippedStr.indexOf(',') !== -1) {
    return hslComma.test(strippedStr);
  }

  return hslSpace.test(strippedStr);
}