Adding tests for ipv4/ipv6 functionality

Author: adipirro

test/server.js

@@ -1,5 +1,6 @@
 const assert = require('assert');
 const net = require('net');
+const os = require('os');
 const helpers = require('../lib/helpers');
 const consts = require('../lib/constants');
 const CacheServer = require('../lib/server/server');
@@ -67,6 +68,57 @@ describe("Server common", function() {
         });
     });
 
+    describe("Ipv6", function() {
+        const ipv6Server = new CacheServer(cache, {port: 0, allowIpv6: true});
+
+        before(function () {  
+            var interfaces = os.networkInterfaces();
+            var ipv6Available = false;
+            Object.keys(interfaces).forEach(function (interfaceName){
+                interfaces[interfaceName].forEach(function (address){
+                    if(address.family === "IPv6"){
+                        ipv6Available = true;
+                    }
+                });
+            });
+
+            if(!ipv6Available){
+                console.log("Skipping IPv6 tests because IPv6 is not available on this machine");
+                this.skip();
+            }   
+
+            return ipv6Server.start(err => assert(!err, `Cache Server reported error! ${err}`));
+        });
+    
+        after(function() {
+            ipv6Server.stop();
+        });
+    
+        it("should bind to ipv6 when allowed", function(done) {
+            var serverAddress = ipv6Server._server.address();
+            assert.strictEqual(serverAddress.family, "IPv6");
+            done();
+        });
+
+    });
+    describe("Ipv4", function() {
+        const ipv4Server = new CacheServer(cache, {port: 0, allowIpv6: false});
+
+        before(function () {
+            return ipv4Server.start(err => assert(!err, `Cache Server reported error! ${err}`));
+        });
+    
+        after(function() {
+            ipv4Server.stop();
+        });
+
+        it("should bind to ipv4 when ipv6 not allowed", function(done) {
+            var serverAddress = ipv4Server._server.address();
+            assert.strictEqual(serverAddress.family, "IPv4");
+            done();
+        });
+    });
+
     describe("Other", function() {
         it("should force close the socket when a quit (q) command is received", function(done) {
             client = net.connect({port: server.port}, function (err) {
@@ -92,6 +144,7 @@ describe("Server common", function() {
                 client.write(helpers.encodeInt32(consts.PROTOCOL_VERSION));
                 client.write('xx');
             });
-        })
+        });
     })
-});
+});
+