public async void GivenModel_WhenInitIsCalled_ThenPostsAreLoaded() { var posts = new [] { new Post(), new Post() }; _getPostsCommand.Execute().Returns(Task.FromResult(posts as IEnumerable <Post>)); _postViewModelMapper.Map(Arg.Any <Post>()).Returns(new PostViewModel()); await _model.Init(); _getPostsCommand.Received(1).Execute(); _postViewModelMapper.Received(1).Map(posts[0]); _postViewModelMapper.Received(1).Map(posts[1]); _model.Posts.Count.Should().Be(2); }