docxtemplater/js/tests/string-repeat.js

docx and pptx generator working with templates and data (like Mustache, for Word and Powerpoint documents)

"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;