public void Execute_WhenUserIsNotFollowingAnyone_ReturnNull()
        {
            var userServiceMock = new Mock<IUserService>();
            userServiceMock.Setup(x => x.GetUserByUserName(It.IsAny<string>()))
                .Returns(new User { UserName = "******", SubscribedTo = null });

            var showWallCommand = new ShowWallCommand(userServiceMock.Object);

            var result = showWallCommand.Execute("franta");

            Assert.IsNull(result);
        }
        public void Execute_WhenUserIsNotFollowingAnyone_ReturnNull()
        {
            var userServiceMock = new Mock <IUserService>();

            userServiceMock.Setup(x => x.GetUserByUserName(It.IsAny <string>()))
            .Returns(new User {
                UserName = "******", SubscribedTo = null
            });

            var showWallCommand = new ShowWallCommand(userServiceMock.Object);

            var result = showWallCommand.Execute("franta");

            Assert.IsNull(result);
        }