test: refactor net.connect ipv6 options test

Use common.skipIfNoIpv6Localhost

Author: joyeecheung

test/parallel/test-net-connect-options-ipv6.js

@@ -19,71 +19,44 @@
 // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 // USE OR OTHER DEALINGS IN THE SOFTWARE.
 
+// This tests that the family option of net.connect is hornored.
+
 'use strict';
 const common = require('../common');
-if (!common.hasIPv6)
-  common.skip('no IPv6 support');
-
-const assert = require('assert');
-const net = require('net');
 
-const hosts = common.localIPv6Hosts;
-let hostIdx = 0;
-let host = hosts[hostIdx];
-let localhostTries = 10;
+common.skipIfNoIpv6Localhost((ipv6Host) => {
+  const assert = require('assert');
+  const net = require('net');
 
-const server = net.createServer({ allowHalfOpen: true }, function(socket) {
-  socket.resume();
-  socket.on('end', common.mustCall());
-  socket.end();
-});
+  const server = net.createServer({
+    allowHalfOpen: true
+  }, common.mustCall((socket) => {
+    assert.strictEqual('::1', socket.remoteAddress);
+    socket.resume();
+    socket.on('end', common.mustCall());
+    socket.end();
+  }));
 
-server.listen(0, '::1', tryConnect);
+  server.listen(0, '::1', common.mustCall(tryConnect));
 
-function tryConnect() {
-  const client = net.connect({
-    host: host,
-    port: server.address().port,
-    family: 6,
-    allowHalfOpen: true
-  }, function() {
-    console.error('client connect cb');
-    client.resume();
-    client.on('end', common.mustCall(function() {
-      setTimeout(function() {
-        assert(client.writable);
-        client.end();
-      }, 10);
-    }));
-    client.on('close', function() {
-      server.close();
-    });
-  }).on('error', function(err) {
-    // ENOTFOUND means we don't have the requested address. In this
-    // case we try the next one in the list and if we run out of
-    // candidates we assume IPv6 is not supported on the
-    // machine and skip the test.
-    // EAI_AGAIN means we tried to remotely resolve the address and
-    // timed out or hit some intermittent connectivity issue with the
-    // dns server.  Although we are looking for local loopback addresses
-    // we may go remote since the list we search includes addresses that
-    // cover more than is available on any one distribution. The
-    // net is that if we get an EAI_AGAIN we were looking for an
-    // address which does not exist in this distribution so the error
-    // is not significant and we should just move on and try the
-    // next address in the list.
-    if ((err.syscall === 'getaddrinfo') && ((err.code === 'ENOTFOUND') ||
-                                            (err.code === 'EAI_AGAIN'))) {
-      if (host !== 'localhost' || --localhostTries === 0)
-        host = hosts[++hostIdx];
-      if (host)
-        tryConnect();
-      else {
+  function tryConnect() {
+    const client = net.connect({
+      host: ipv6Host,
+      port: server.address().port,
+      family: 6,
+      allowHalfOpen: true
+    }, common.mustCall(() => {
+      console.error('client connect cb');
+      client.resume();
+      client.on('end', common.mustCall(function() {
+        setTimeout(function() {
+          assert(client.writable);
+          client.end();
+        }, 10);
+      }));
+      client.on('close', function() {
         server.close();
-        common.skip('no IPv6 localhost support');
-      }
-      return;
-    }
-    throw err;
-  });
-}
+      });
+    }));
+  }
+});