/** Used to compose unicode character classes. */
const rsAstralRange = '\\ud800-\\udfff';
const rsComboMarksRange = '\\u0300-\\u036f';
const reComboHalfMarksRange = '\\ufe20-\\ufe2f';
const rsComboSymbolsRange = '\\u20d0-\\u20ff';
const rsComboRange = rsComboMarksRange + reComboHalfMarksRange + rsComboSymbolsRange;
const rsVarRange = '\\ufe0e\\ufe0f';

/** Used to compose unicode capture groups. */
const rsZWJ = '\\u200d';

/** Used to detect strings with [zero-width joiners or code points from the astral planes](http://eev.ee/blog/2015/09/12/dark-corners-of-unicode/). */
const reHasUnicode = RegExp(`[${ rsZWJ + rsAstralRange + rsComboRange + rsVarRange }]`);

/**
 * Checks if `string` contains Unicode symbols.
 *
 * @private
 * @param {string} string The string to inspect.
 * @returns {boolean} Returns `true` if a symbol is found, else `false`.
 */
function hasUnicode(string) {
  return reHasUnicode.test(string);
}

export default hasUnicode;