docxtemplater/js/tests/string-repeat.js

Generate docx, pptx, and xlsx from templates (Word, Powerpoint and Excel documents), from Node.js, the Browser and the command line

"use strict";

function repeat(input, count) {
  if (input == null) {
    throw new TypeError("can't convert " + input + " to object");
  }
  var str = "" + input;
  // To convert string to integer.
  count = +count;
  if (count < 0) {
    throw new RangeError("repeat count must be non-negative");
  }
  if (count === Infinity) {
    throw new RangeError("repeat count must be less than infinity");
  }
  count = Math.floor(count);
  if (str.length === 0 || count === 0) {
    return "";
  }

  /*
   * Ensuring count is a 31-bit integer allows us to heavily optimize the
   * main part. But anyway, most current (August 2014) browsers can't handle
   * strings 1 << 28 chars or longer, so:
   */
  if (str.length * count >= 1 << 28) {
    throw new RangeError("repeat count must not overflow maximum string size");
  }
  var maxCount = str.length * count;
  count = Math.floor(Math.log(count) / Math.log(2));
  while (count) {
    str += str;
    count--;
  }
  str += str.substring(0, maxCount - str.length);
  return str;
}
module.exports = repeat;