stylelint-bundle-worker.js
function fillRange(start, stop, step, options) {
  if (typeof start === 'undefined') {
    return [];
  }

  if (typeof stop === 'undefined' || start === stop) {
    // special case, for handling negative zero
    var isString = typeof start === 'string';
    if (isNumber(start) && !toNumber(start)) {
      return [isString ? '0' : 0];
    }
    return [start];
  }

  if (typeof step !== 'number' && typeof step !== 'string') {
    options = step;
    step = undefined;
  }

  if (typeof options === 'function') {
    options = { transform: options };
  }

  var opts = extend({step: step}, options);
  if (opts.step && !isValidNumber(opts.step)) {
    if (opts.strictRanges === true) {
      throw new TypeError('expected options.step to be a number');
    }
    return [];
  }

  opts.isNumber = isValidNumber(start) && isValidNumber(stop);
  if (!opts.isNumber && !isValid(start, stop)) {
    if (opts.strictRanges === true) {
      throw new RangeError('invalid range arguments: ' + util.inspect([start, stop]));
    }
    return [];
  }

  opts.isPadded = isPadded(start) || isPadded(stop);
  opts.toString = opts.stringify
    || typeof opts.step === 'string'
    || typeof start === 'string'
    || typeof stop === 'string'
    || !opts.isNumber;

  if (opts.isPadded) {
    opts.maxLength = Math.max(String(start).length, String(stop).length);
  }

  // support legacy minimatch/fill-range options
  if (typeof opts.optimize === 'boolean') opts.toRegex = opts.optimize;
  if (typeof opts.makeRe === 'boolean') opts.toRegex = opts.makeRe;
  return expand(start, stop, opts);
}
function fillRange(start, stop, step, options) {
  if (typeof start === 'undefined') {
    return [];
  }

  if (typeof stop === 'undefined' || start === stop) {
    // special case, for handling negative zero
    var isString = typeof start === 'string';
    if (isNumber(start) && !toNumber(start)) {
      return [isString ? '0' : 0];
    }
    return [start];
  }

  if (typeof step !== 'number' && typeof step !== 'string') {
    options = step;
    step = undefined;
  }

  if (typeof options === 'function') {
    options = { transform: options };
  }

  var opts = extend({step: step}, options);
  if (opts.step && !isValidNumber(opts.step)) {
    if (opts.strictRanges === true) {
      throw new TypeError('expected options.step to be a number');
    }
    return [];
  }

  opts.isNumber = isValidNumber(start) && isValidNumber(stop);
  if (!opts.isNumber && !isValid(start, stop)) {
    if (opts.strictRanges === true) {
      throw new RangeError('invalid range arguments: ' + util.inspect([start, stop]));
    }
    return [];
  }

  opts.isPadded = isPadded(start) || isPadded(stop);
  opts.toString = opts.stringify
    || typeof opts.step === 'string'
    || typeof start === 'string'
    || typeof stop === 'string'
    || !opts.isNumber;

  if (opts.isPadded) {
    opts.maxLength = Math.max(String(start).length, String(stop).length);
  }

  // support legacy minimatch/fill-range options
  if (typeof opts.optimize === 'boolean') opts.toRegex = opts.optimize;
  if (typeof opts.makeRe === 'boolean') opts.toRegex = opts.makeRe;
  return expand(start, stop, opts);
}
Return a range of numbers or letters.

@param  {String} `start` Start of the range
@param  {String} `stop` End of the range
@param  {String} `step` Increment or decrement to use.
@param  {Function} `fn` Custom function to modify each element in the range.
@return {Array}