added NICK already registered test

test/server.js

@@ -2,22 +2,22 @@ const assert = require('assert');
 const EventEmitter = require('events');
 const IRCServer = require("../src/server.js");
 
-describe('IRC server', function() {
-  describe('#create()', function() {
-    it("should return a socket server", function() {
+describe('IRC server', function () {
+    describe('#create()', function () {
+        it("should return a socket server", function () {
             const server = IRCServer.create()
             assert.equal(server.eventNames().toString(), ["connection", "error"].toString())
         })
     })
-  describe("on('connection')", function() {
-    it("should handle a PING command -> PING irc.example.com", function(done) {
+    describe("on('connection')", function () {
+        it("should handle a PING command -> PING irc.example.com", function (done) {
             const server = IRCServer.create()
             let mockedSock = new EventEmitter()
-      mockedSock.write = function(data) {
+            mockedSock.write = function (data) {
                 assert.equal(data.toString("ascii"), "PONG irc.example.com\r\n")
                 done()
             }
-      mockedSock.destroy = function() {
+            mockedSock.destroy = function () {
                 done("Destroyed socket without answering")
             }
 
@@ -37,6 +37,22 @@ describe('IRC server', function() {
                 done("Destroyed socket without answering")
             }
 
+            server.emit("connection", mockedSock)
+            mockedSock.emit('data', Buffer.from("NICK some_nick\r\n", "ascii"))
+        })
+    }),
+        describe("NICK already registered", function () {
+            it("should handle a NICK command -> NICK some_nickname", function (done) {
+                const server = IRCServer.create()
+                let mockedSock = new EventEmitter()
+                mockedSock.write = function (data) {
+                    assert.equal(data.toString("ascii"), "433")
+                    done()
+                }
+                mockedSock.destroy = function () {
+                    done("Destroyed socket without answering")
+                }
+
                 server.emit("connection", mockedSock)
                 mockedSock.emit('data', Buffer.from("NICK some_nick\r\n", "ascii"))
             })