@polkadot/util/is/ip.js

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 v6s = '[a-fA-F\\d]{1,4}';
const v6 = `
(?:
(?:${v6s}:){7}(?:${v6s}|:)|                                    // 1:2:3:4:5:6:7::  1:2:3:4:5:6:7:8
(?:${v6s}:){6}(?:${v4}|:${v6s}|:)|                             // 1:2:3:4:5:6::    1:2:3:4:5:6::8   1:2:3:4:5:6::8  1:2:3:4:5:6::1.2.3.4
(?:${v6s}:){5}(?::${v4}|(?::${v6s}){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
(?:${v6s}:){4}(?:(?::${v6s}){0,1}:${v4}|(?::${v6s}){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
(?:${v6s}:){3}(?:(?::${v6s}){0,2}:${v4}|(?::${v6s}){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
(?:${v6s}:){2}(?:(?::${v6s}){0,3}:${v4}|(?::${v6s}){1,5}|:)| // 1:2::            1:2::4:5:6:7:8   1:2::8          1:2::4:5:6:7:1.2.3.4
(?:${v6s}:){1}(?:(?::${v6s}){0,4}:${v4}|(?::${v6s}){1,6}|:)| // 1::              1::3:4:5:6:7:8   1::8            1::3:4:5:6:7:1.2.3.4
(?::(?:(?::${v6s}){0,5}:${v4}|(?::${v6s}){1,7}|:))             // ::2:3:4:5:6:7:8  ::2:3:4:5:6:7:8  ::8             ::1.2.3.4
)(?:%[0-9a-zA-Z]{1,})?                                             // %eth0            %1
`.replace(/\s*\/\/.*$/gm, '').replace(/\n/g, '').trim();
const v46Exact = new RegExp(`(?:^${v4}$)|(?:^${v6}$)`);
const v4exact = new RegExp(`^${v4}$`);
const v6exact = new RegExp(`^${v6}$`);
/**
 * @name isIp
 * @summary Tests if the value is a valid IP address
 * @description
 * Checks to see if the value is a valid IP address. Optionally check for either v4/v6
 * @example
 * <BR>
 *
 * ```javascript
 * import { isIp } from '@polkadot/util';
 *
 * isIp('192.168.0.1')); // => true
 * isIp('1:2:3:4:5:6:7:8'); // => true
 * isIp('192.168.0.1', 'v6')); // => false
 * isIp('1:2:3:4:5:6:7:8', 'v4'); // => false
 * ```
 */
export function isIp(value, type) {
    switch (type) {
        case 'v4': return v4exact.test(value);
        case 'v6': return v6exact.test(value);
        default: return v46Exact.test(value);
    }
}