Function truncate

lodash.js:15196–15250

* Truncates `string` if it's longer than the given maximum string length. * The last characters of the truncated string are replaced with the omission * string which defaults to "...". * * @static * @memberOf _ * @since 4.0.0 * @category String * @param {strin

(string, options)

     * // => 'hi-diddly-ho there, neig [...]'
     */
    function truncate(string, options) {
      var length = DEFAULT_TRUNC_LENGTH,
          omission = DEFAULT_TRUNC_OMISSION;

      if (isObject(options)) {
        var separator = 'separator' in options ? options.separator : separator;
        length = 'length' in options ? toInteger(options.length) : length;
        omission = 'omission' in options ? baseToString(options.omission) : omission;
      }
      string = toString(string);

      var strLength = string.length;
      if (hasUnicode(string)) {
        var strSymbols = stringToArray(string);
        strLength = strSymbols.length;
      }
      if (length >= strLength) {
        return string;
      }
      var end = length - stringSize(omission);
      if (end < 1) {
        return omission;
      }
      var result = strSymbols
        ? castSlice(strSymbols, 0, end).join('')
        : string.slice(0, end);

      if (separator === undefined) {
        return result + omission;
      }
      if (strSymbols) {
        end += (result.length - end);
      }
      if (isRegExp(separator)) {
        if (string.slice(end).search(separator)) {
          var match,
              substring = result;

          if (!separator.global) {
            separator = RegExp(separator.source, toString(reFlags.exec(separator)) + 'g');
          }
          separator.lastIndex = 0;
          while ((match = separator.exec(substring))) {
            var newEnd = match.index;
          }
          result = result.slice(0, newEnd === undefined ? end : newEnd);
        }
      } else if (string.indexOf(baseToString(separator), end) != end) {
        var index = result.lastIndexOf(separator);
        if (index > -1) {
          result = result.slice(0, index);
        }
      }
      return result + omission;
    }

    /**
     * The inverse of `_.escape`; this method converts the HTML entities