Add dnsLookupIpVersion option

test/http.ts

@@ -7,6 +7,27 @@ import getStream = require('get-stream');
 import pEvent = require('p-event');
 import got, {HTTPError, UnsupportedProtocolError} from '../source';
 import withServer from './helpers/with-server';
+import os = require('os');
+
+const ifaces = os.networkInterfaces();
+let IPv6supported = false;
+for (const ifname in ifaces) {
+	if (!Object.prototype.hasOwnProperty.call(ifaces, ifname)) {
+		continue;
+	}
+
+	const iface = ifaces[ifname]!;
+	for (const addr of iface) {
+		if (addr.family === 'IPv6' && addr.internal) {
+			IPv6supported = true;
+			break;
+		}
+	}
+
+	if (IPv6supported) {
+		break;
+	}
+}
 
 const echoIp: Handler = (request, response) => {
 	const address = request.connection.remoteAddress;
@@ -269,16 +290,15 @@ test('does not destroy completed requests', withServer, async (t, server, got) =
 });
 
 test('IPv6 request', withServer, async (t, server) => {
+	if (!IPv6supported) {
+		return;
+	}
+
 	server.get('/ok', echoIp);
 
-	try {
-		const response = await got(`http://[::1]:${server.port}/ok`);
+	const response = await got(`http://[::1]:${server.port}/ok`);
 
-		t.is(response.body, '::1');
-	} catch {
-		// Assumes that IPv6 is not supported
-		t.pass();
-	}
+	t.is(response.body, '::1');
 });
 
 test('DNS auto', withServer, async (t, server, got) => {
@@ -302,16 +322,15 @@ test('DNS IPv4', withServer, async (t, server, got) => {
 });
 
 test('DNS IPv6', withServer, async (t, server, got) => {
+	if (!IPv6supported) {
+		return;
+	}
+
 	server.get('/ok', echoIp);
 
-	try {
-		const response = await got('ok', {
-			dnsLookupIpVersion: 'ipv6'
-		});
+	const response = await got('ok', {
+		dnsLookupIpVersion: 'ipv6'
+	});
 
-		t.true(isIPv6(response.body));
-	} catch {
-		// Assumes that IPv6 is not supported
-		t.pass();
-	}
+	t.true(isIPv6(response.body));
 });