@chainsafe/is-ip

Check if a string is an IP address

Install

1npm install @chainsafe/is-ip

Example

Check if a string is an IP address

1import { expect } from "chai";
2import {
3	isIPv4,
4	isIPv6,
5	isIP,
6	ipVersion,
7} from "@chainsafe/is-ip";
8
9// check if a string is a valid IPv4
10expect(isIPv4("127.0.0.1")).to.equal(true);
11
12// check if a string is a valid IPv6
13expect(isIPv6("127.0.0.1")).to.equal(false);
14
15// check if a string is a valid IPv4 or IPv6
16expect(isIP("127.0.0.1")).to.equal(true);
17
18// return 4, 6, or undefined
19expect(ipVersion("127.0.0.1")).to.equal(4);
20expect(ipVersion("1:2:3:4:5:6:7:8")).to.equal(6);
21expect(ipVersion("invalid ip")).to.equal(undefined);

Parse a string into IP address bytes

1import { expect } from "chai";
2import {
3	parseIPv4,
4	parseIPv4Mapped,
5	parseIPv6,
6	parseIP,
7} from "@chainsafe/is-ip/parse";
8
9// parse a string into IPv4 bytes
10const b1 = parseIPv4("127.0.0.1");
11expect(b1).to.deep.equal(Uint8Array.from([127, 0, 0, 1]));
12
13// parse a string into IPv6 bytes
14const b2 = parseIPv6("::1");
15expect(b2).to.deep.equal(Uint8Array.from([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1]));
16
17// parse an IPv4 string into IPv4-mapped IPv6 bytes
18const b3 = parseIPv4Mapped("127.0.0.1");
19expect(b3).to.deep.equal(Uint8Array.from([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 255, 255, 127, 0, 0, 1]));
20
21// parse a string into either IPv4 or IPv6 bytes
22const b4 = parseIP("127.0.0.1");
23expect(b4).to.deep.equal(Uint8Array.from([127, 0, 0, 1]));
24
25const b5 = parseIP("::1");
26expect(b5).to.deep.equal(Uint8Array.from([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1]));
27
28const b6 = parseIP("127.0.0.1", true);
29expect(b6).to.deep.equal(Uint8Array.from([0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 255, 255, 127, 0, 0, 1]));
30
31// parseIP* functions return undefined on invalid input
32expect(parseIP("not an IP")).to.equal(undefined);

License

MIT