public void BroadcastMessageToChannel() { string testChannel = "testChannel"; string testMessage = "test message"; string testUser = "******"; dynamic broadCast = new ExpandoObject(); broadCast.sendChannelMessage = new Action <string, string>((user, message) => { this.isSent = true; Assert.AreEqual(testUser, user, "the user was not supplied correctly"); Assert.AreEqual(testMessage, message, "the message was not supplied correctly"); }); IRequest request = base.BuildTestRequest().Object; var mockClients = new Mock <IHubCallerConnectionContext <dynamic> >(); mockClients.Setup(m => m.Group(testChannel)).Returns((ExpandoObject)broadCast); var mockHubCallerContext = new Mock <HubCallerContext>(request, "1"); ChatHub hub = new ChatHub() { Context = mockHubCallerContext.Object, Clients = mockClients.Object, Groups = mockGroupManager.Object }; hub.ChannelBroadCast(testChannel, testUser, testMessage); }