ipUtils – Utilities for working with IP address whitelist/blacklist patterns

ipUtils.js

/**
 * @file Utilities for working with IP address whitelist/blacklist patterns
 * @author Avana Vana
 * @module ipUtils
 * @version 2.0.2
 */

module.exports = {
  
  /*
   * Returns an array of IP addresses from a string of space separated IP patterns, expanding any wildcard characters (*)
   *
   * @deprecated /!\ DO NOT USE /!\ superseded by {@link patternsToRegEx}, which is far more efficient—just a single IP with two wildcards passed to this method creates an array with 65,536 elements...with four wildcards it would be ~4.3 billion elements in length...but just too cool of a one-liner for me to delete
   * @method patternsToArray
   * @param {string} patterns - List of ip address patterns, space-separated, with optional wildcard parts (*)
   * @returns {string[]} Flat array of all combinatorically possible ip addresses using given wildcards
   *
   * @example <caption>Without wildcards (*)</caption>
   * // returns ['67.118.0.1','255.255.1.1'] (2)
   * patternsToArray('67.118.0.1 255.255.1.1');
   *
   * @example <caption>With wildcards (*)</caption>
   * // returns ['67.118.0.1','255.255.1.0','255.255.1.1', ... , '255.255.1.254', '255.255.1.255'] (257)
   * patternsToArray('67.118.0.1 255.255.1.*');
   */
  
  patternsToArray: (patterns) => patterns
    .split(' ')
    .map((pattern) => pattern
      .split('.')
      .map((part) => (part === '*' ? [...Array(256).keys()] : [part])))
    .flatMap((ip) => [...ip]
      .reduce((a, b) => a
        .flatMap((d) => b
          .map((e) => [d, e]
            .flat()))))
    .map((ip) => ip
      .join('.')),
  
  /*
   * Returns a regular expression from a string of space-separated IP patterns, with wildcard characters (*)
   *
   * @method patternsToRegEx
   * @param {string} patterns - List of ip addresses, space-separated, with optional wildcards (*)
   * @returns {RegExp} Regular expression equivalent to IP patterns
   *
   * @example <caption>Without wildcards (*)</caption>
   * // returns true
   * let patterns = '67.118.0.1 255.255.1.1';
   * patternsToRegEx(patterns).test('67.118.0.1');
   *
   * @example <caption>With wildcards (*)</caption>
   * // returns true
   * let patterns = '67.118.0.1 255.255.*.*';
   * patternsToRegEx(patterns).test('255.255.0.1');
   */
  
  patternsToRegEx: (patterns) => new RegExp(
    `(?:${patterns
      .split(' ')
      .map((pattern) => pattern
        .replace(/\./g, '\\.')
        .replace(/\*/g, '\\b(?:1\\d{2}|2[0-4]\\d|[1-9]?\\d|25[0-5])\\b'))
      .join('|')})`)

}