gistfile1.cs

[Fact]
public void Fetch_WithBlogSelectedAndOneResult_DisplaysOnePost()
{
    // arrange
    var result = new[] { new Post() };

    var task = MockTask(result);
    metaWeblogService
         .GetRecentPostsAsync(Arg.Any<BlogSetting>(), Arg.Any<int>())
         .Returns(task);

    subject.SelectedBlog = new BlogSetting();

    // act
    subject.Fetch();

    task.ExecuteAndCheck(() => Assert.NotEmpty(subject.Posts));
}