public async Task SendWritesToWebSocketOutputStream() { var fakeOutputStream = new FakeOutputStream(); var fakeWebSocket = new FakeWebSocket { OutputStream = fakeOutputStream }; await WebSocketTransport.Send(fakeWebSocket, "42.42"); var writeAsyncInvocations = fakeOutputStream.GetInvocations("WriteAsync").ToArray(); Assert.Equal(1, writeAsyncInvocations.Length); Assert.Equal(5u, ((IBuffer)writeAsyncInvocations[0][0]).Length); }