public void Get_ArgumentNullException()
        {
            // arrange
            HttpContextBase httpContext = null;
            string pathToFilename = Setup.GetDataPath();
            FileDatasource fileDatasource = new FileDatasource(pathToFilename, httpContext);

            // act
            try
            {
                fileDatasource.GetFeeds(null);
                Assert.Fail("exception not thrown");
            }
            catch (ArgumentNullException)
            {
            }
            catch
            {
                Assert.Fail("Invalid exception");
            }
        }
        public void Get_Feeds_File()
        {
            // arrange
            HttpContextBase httpContext = null;
            string pathToFilename = Setup.GetDataPath();
            FileDatasource fileDatasource = new FileDatasource(pathToFilename, httpContext);
            string filename = this.filename;

            fileDatasource.RssFeeds = this.rssFeeds;
            fileDatasource.Set();

            // act
            RssFeeds actual = fileDatasource.GetFeeds(fileDatasource.FileName);

            // assert
            Assert.IsNotNull(actual);

            // cleanup
            File.Delete(filename);
        }