Use IPv6 by default, add useIPv6 option (#12)

Co-authored-by: Sindre Sorhus <sindresorhus@gmail.com>

index.d.ts

@@ -1,9 +1,18 @@
 declare namespace ipify {
 	interface Options {
+		/**
+		Use the IPv6 API endpoint. The IPv6 endpoint will return an IPv6 address if available, IPv4 address otherwise.
+
+		Setting the `endpoint` option will override this.
+
+		@default true
+		*/
+		readonly useIPv6?: boolean;
+
 		/**
 		Custom API endpoint.
 
-		@default 'https://api.ipify.org'
+		@default 'https://api6.ipify.org'
 		*/
 		readonly endpoint?: string;
 	}
@@ -18,8 +27,11 @@ Get your public IP address.
 ```
 import ipify = require('ipify');
 
-(async => {
+(async () => {
 	console.log(await ipify());
+	//=> '2001:0db8:85a3:0000:0000:8a2e:0370:7334'
+
+	console.log(await ipify({useIPv6: false});
 	//=> '82.142.31.236'
 })();
 ```

index.js

@@ -1,12 +1,14 @@
 'use strict';
 const got = require('got');
 
-module.exports = async options => {
-	options = {
-		endpoint: 'https://api.ipify.org',
-		...options
-	};
+const IPIFY_ENDPOINT_IPV4 = 'https://api.ipify.org';
+const IPIFY_ENDPOINT_IPV6 = 'https://api6.ipify.org';
 
-	const {body} = await got(options.endpoint);
+module.exports = async ({useIPv6 = true, endpoint} = {}) => {
+	if (endpoint === undefined) {
+		endpoint = useIPv6 ? IPIFY_ENDPOINT_IPV6 : IPIFY_ENDPOINT_IPV4;
+	}
+
+	const {body} = await got(endpoint);
 	return body;
 };

index.test-d.ts

@@ -3,4 +3,6 @@ import ipify = require('.');
 
 const options: ipify.Options = {};
 expectType<Promise<string>>(ipify());
+expectType<Promise<string>>(ipify({useIPv6: true}));
+expectType<Promise<string>>(ipify({useIPv6: false}));
 expectType<Promise<string>>(ipify({endpoint: 'https://example.com'}));

readme.md

@@ -17,8 +17,11 @@ $ npm install ipify
 ```js
 const ipify = require('ipify');
 
-(async => {
+(async () => {
 	console.log(await ipify());
+	//=> '2001:0db8:85a3:0000:0000:8a2e:0370:7334'
+
+	console.log(await ipify({useIPv6: false});
 	//=> '82.142.31.236'
 })();
 ```
@@ -34,10 +37,19 @@ Returns a `Promise<string>` with an IP address.
 
 Type: `object`
 
+##### useIPv6
+
+Type: `boolean`<br>
+Default: `true`
+
+Use the IPv6 API endpoint. The IPv6 endpoint will return an IPv6 address if available, IPv4 address otherwise.
+
+Setting the `endpoint` option will override this.
+
 ##### endpoint
 
 Type: `string`<br>
-Default: `'https://api.ipify.org'`
+Default: `'https://api6.ipify.org'`
 
 Custom API endpoint.
 

test.js

@@ -4,5 +4,12 @@ import ipify from '.';
 
 test('main', async t => {
 	t.true(isIp(await ipify()));
-	t.true(isIp(await ipify({endpoint: 'https://api.ipify.org'})));
+});
+
+test('useIPv6:false', async t => {
+	t.true(isIp.v4(await ipify({useIPv6: false})));
+});
+
+test('endpoint:custom', async t => {
+	t.true(isIp.v4(await ipify({endpoint: 'https://api.ipify.org'})));
 });