ip.js

/*! Based on ip-regex#https://github.com/sindresorhus/ip-regex/blob/main/index.js#LL1-L34.
 MIT License. Sindre Sorhus <sindresorhus@gmail.com> (https://sindresorhus.com) */
const v4 =
  '(?:25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]\\d|\\d)(?:\\.(?:25[0-5]|2[0-4]\\d|1\\d\\d|[1-9]\\d|\\d)){3}'

const v6segment = '[a-fA-F\\d]{1,4}'

const v6 = `
(?:
(?:${v6segment}:){7}(?:${v6segment}|:)|                                    // 1:2:3:4:5:6:7::  1:2:3:4:5:6:7:8
(?:${v6segment}:){6}(?:${v4}|:${v6segment}|:)|                             // 1:2:3:4:5:6::    1:2:3:4:5:6::8   1:2:3:4:5:6::8  1:2:3:4:5:6::1.2.3.4
(?:${v6segment}:){5}(?::${v4}|(?::${v6segment}){1,2}|:)|                   // 1:2:3:4:5::      1:2:3:4:5::7:8   1:2:3:4:5::8    1:2:3:4:5::7:1.2.3.4
(?:${v6segment}:){4}(?:(?::${v6segment}){0,1}:${v4}|(?::${v6segment}){1,3}|:)| // 1:2:3:4::        1:2:3:4::6:7:8   1:2:3:4::8      1:2:3:4::6:7:1.2.3.4
(?:${v6segment}:){3}(?:(?::${v6segment}){0,2}:${v4}|(?::${v6segment}){1,4}|:)| // 1:2:3::          1:2:3::5:6:7:8   1:2:3::8        1:2:3::5:6:7:1.2.3.4
(?:${v6segment}:){2}(?:(?::${v6segment}){0,3}:${v4}|(?::${v6segment}){1,5}|:)| // 1:2::            1:2::4:5:6:7:8   1:2::8          1:2::4:5:6:7:1.2.3.4
(?:${v6segment}:){1}(?:(?::${v6segment}){0,4}:${v4}|(?::${v6segment}){1,6}|:)| // 1::              1::3:4:5:6:7:8   1::8            1::3:4:5:6:7:1.2.3.4
(?::(?:(?::${v6segment}){0,5}:${v4}|(?::${v6segment}){1,7}|:))             // ::2:3:4:5:6:7:8  ::2:3:4:5:6:7:8  ::8             ::1.2.3.4
)(?:%[0-9a-zA-Z]{1,})?                                             // %eth0            %1
`
  .replace(/\s*\/\/.*$/gm, '')
  .replace(/\n/g, '')
  .trim()

// Pre-compile only the exact regexes because adding a global flag make regexes stateful
const v46Exact = new RegExp(`(?:^${v4}$)|(?:^${v6}$)`)
const v4Exact = new RegExp(`^${v4}$`)
const v6Exact = new RegExp(`^${v6}$`)

module.exports = {
  isIP (ip = '') {
    return v46Exact.test(ip)
  },
  isIPv4 (ip = '') {
    return v4Exact.test(ip)
  },
  isIPv6 (ip = '') {
    return v6Exact.test(ip)
  },
  inferIPVersion (pseudo = '') {
    let result = 0
    if (this.isIPv4(pseudo)) result = 4
    else if (this.isIPv6(pseudo)) result = 6

    return result
  }
}