test: fix flaky IPv6/localhost tests

Fixes: #7288

Author: Trott

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

@@ -5,29 +5,50 @@ 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');
+
+// In a more perfect world, we could just use `localhost` for the host.
+// Alas, we live in a world where some distributions do not map localhost
+// to ::1 by default. See https://github.com/nodejs/node/issues/7288
+
+var index = 0;
+checkForLocalhost(common.localIPv6Hosts[index]);
+
+function checkForLocalhost(host) {
+  dns.lookup(host, 6, (err, address) => {
+    if (!err)
+      return runTest(host);
+    index = index + 1;
+    if (index < common.localIPv6Hosts.length)
+      return checkForLocalhost(common.localIPv6Hosts[index]);
+    common.fail('Could not find an IPv6 host for ::1');
+  });
+}
+
+const runTest = common.mustCall(function runTest(host) {
+  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,
+      port: common.PORT,
+      family: 6,
+      ciphers,
+      rejectUnauthorized: false,
+    };
+    // Will fail with ECONNREFUSED if the address family is not honored.
+    https.get(options, common.mustCall(common.mustCall(function() {
+      assert.strictEqual('::1', this.socket.remoteAddress);
+      this.destroy();
+    })));
   }));
 });

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

@@ -5,28 +5,49 @@ if (!common.hasCrypto) {
   return;
 }
 
-const assert = require('assert');
-const tls = require('tls');
-
 if (!common.hasIPv6) {
   common.skip('no IPv6 support');
   return;
 }
 
-const ciphers = 'AECDH-NULL-SHA';
-tls.createServer({ ciphers }, function() {
-  this.close();
-}).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.
-  tls.connect(options).once('secureConnect', common.mustCall(function() {
-    assert.strictEqual('::1', this.remoteAddress);
-    this.destroy();
+const assert = require('assert');
+const tls = require('tls');
+const dns = require('dns');
+
+// In a more perfect world, we could just use `localhost` for the host.
+// Alas, we live in a world where some distributions do not map localhost
+// to ::1 by default. See https://github.com/nodejs/node/issues/7288
+
+var index = 0;
+checkForLocalhost(common.localIPv6Hosts[index]);
+
+function checkForLocalhost(host) {
+  dns.lookup(host, 6, (err, address) => {
+    if (!err)
+      return runTest(host);
+    index = index + 1;
+    if (index < common.localIPv6Hosts.length)
+      return checkForLocalhost(common.localIPv6Hosts[index]);
+    common.fail('Could not find an IPv6 host for ::1');
+  });
+}
+
+const runTest = common.mustCall(function(host) {
+  const ciphers = 'AECDH-NULL-SHA';
+  tls.createServer({ ciphers }, common.mustCall(function() {
+    this.close();
+  })).listen(common.PORT, '::1', common.mustCall(function() {
+    const options = {
+      host,
+      port: common.PORT,
+      family: 6,
+      ciphers,
+      rejectUnauthorized: false,
+    };
+    // Will fail with ECONNREFUSED if the address family is not honored.
+    tls.connect(options).once('secureConnect', common.mustCall(function() {
+      assert.strictEqual('::1', this.remoteAddress);
+      this.destroy();
+    }));
   }));
 });