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

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

Fixes: nodejs#7288

Author: Trott

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

@@ -5,29 +5,42 @@ if (!common.hasCrypto) {
   return;
 }
 
-const assert = require('assert');
-const https = require('https');
-
 if (!common.hasIPv6) {
   common.skip('no IPv6 support');
   return;
 }
 
-const ciphers = 'AECDH-NULL-SHA';
-https.createServer({ ciphers }, function(req, res) {
-  this.close();
-  res.end();
-}).listen(common.PORT, '::1', function() {
-  const options = {
-    host: 'localhost',
-    port: common.PORT,
-    family: 6,
-    ciphers: ciphers,
-    rejectUnauthorized: false,
-  };
-  // Will fail with ECONNREFUSED if the address family is not honored.
-  https.get(options, common.mustCall(function() {
-    assert.strictEqual('::1', this.socket.remoteAddress);
-    this.destroy();
+const assert = require('assert');
+const https = require('https');
+const dns = require('dns');
+
+function runTest() {
+  const ciphers = 'AECDH-NULL-SHA';
+  https.createServer({ ciphers }, common.mustCall(function(req, res) {
+    this.close();
+    res.end();
+  })).listen(common.PORT, '::1', common.mustCall(function() {
+    const options = {
+      host: 'localhost',
+      port: common.PORT,
+      family: 6,
+      ciphers: ciphers,
+      rejectUnauthorized: false,
+    };
+    // Will fail with ECONNREFUSED if the address family is not honored.
+    https.get(options, common.mustCall(function() {
+      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) => { return val.address === '::1'; }))
+    runTest();
+  else
+    common.skip('localhost does not resolve to ::1');
 });