test: fix flaky test-*-connect-address-family

Skip tests if localhost does not resolve to ::1.

Fixes: https://github.com/nodejs/node/issues/7288
PR-URL: https://github.com/nodejs/node/pull/7605
Reviewed-By: Rod Vagg <rod@vagg.org>
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>

test/parallel/test-https-connect-address-family.js

@@ -5,19 +5,21 @@ if (!common.hasCrypto) {
   return;
 }
 
-const assert = require('assert');
-const https = require('https');
-
 if (!common.hasIPv6) {
   common.skip('no IPv6 support');
   return;
 }
 
+const assert = require('assert');
+const https = require('https');
+const dns = require('dns');
+
+function runTest() {
   const ciphers = 'AECDH-NULL-SHA';
-https.createServer({ ciphers }, function(req, res) {
+  https.createServer({ ciphers }, common.mustCall(function(req, res) {
     this.close();
     res.end();
-}).listen(common.PORT, '::1', function() {
+  })).listen(common.PORT, '::1', common.mustCall(function() {
     const options = {
       host: 'localhost',
       port: common.PORT,
@@ -30,4 +32,15 @@ https.createServer({ ciphers }, function(req, res) {
       assert.strictEqual('::1', this.socket.remoteAddress);
       this.destroy();
     }));
+  }));
+}
+
+dns.lookup('localhost', {family: 6, all: true}, (err, addresses) => {
+  if (err)
+    throw err;
+
+  if (addresses.some((val) => val.address === '::1'))
+    runTest();
+  else
+    common.skip('localhost does not resolve to ::1');
 });

test/parallel/test-tls-connect-address-family.js

@@ -5,18 +5,20 @@ if (!common.hasCrypto) {
   return;
 }
 
-const assert = require('assert');
-const tls = require('tls');
-
 if (!common.hasIPv6) {
   common.skip('no IPv6 support');
   return;
 }
 
+const assert = require('assert');
+const tls = require('tls');
+const dns = require('dns');
+
+function runTest() {
   const ciphers = 'AECDH-NULL-SHA';
-tls.createServer({ ciphers }, function() {
+  tls.createServer({ ciphers }, common.mustCall(function() {
     this.close();
-}).listen(common.PORT, '::1', function() {
+  })).listen(common.PORT, '::1', common.mustCall(function() {
     const options = {
       host: 'localhost',
       port: common.PORT,
@@ -29,4 +31,15 @@ tls.createServer({ ciphers }, function() {
       assert.strictEqual('::1', this.remoteAddress);
       this.destroy();
     }));
+  }));
+}
+
+dns.lookup('localhost', {family: 6, all: true}, (err, addresses) => {
+  if (err)
+    throw err;
+
+  if (addresses.some((val) => val.address === '::1'))
+    runTest();
+  else
+    common.skip('localhost does not resolve to ::1');
 });