public void ApplyValuesFromTest() { AssertHelper.ExpectedException <ArgumentNullException>(() => new FeedItem(null, DateTimeOffset.Now, "test", "test", "test")); var itemA1 = new FeedItem(new Uri("http://www.test.com/rss/feed"), new DateTimeOffset(2020, 5, 5, 12, 0, 0, new TimeSpan(1, 0, 0)), "name", "desc", "author"); Assert.AreEqual(new DateTimeOffset(2020, 5, 5, 12, 0, 0, new TimeSpan(1, 0, 0)), itemA1.Date); Assert.AreEqual("name", itemA1.Name); Assert.AreEqual("desc", itemA1.Description); Assert.AreEqual("author", itemA1.Author); var itemA2 = new FeedItem(new Uri("http://www.test.com/rss/feed"), new DateTimeOffset(2022, 5, 5, 12, 0, 0, new TimeSpan(1, 0, 0)), "name2", "desc2", "author2"); itemA1.ApplyValuesFrom(itemA2); Assert.AreEqual(new DateTimeOffset(2022, 5, 5, 12, 0, 0, new TimeSpan(1, 0, 0)), itemA1.Date); Assert.AreEqual("name2", itemA1.Name); Assert.AreEqual("desc2", itemA1.Description); Assert.AreEqual("author2", itemA1.Author); var itemB1 = new FeedItem(new Uri("http://www.test.com/rss/feed2"), new DateTimeOffset(2020, 5, 5, 12, 0, 0, new TimeSpan(1, 0, 0)), "name", "desc", "author"); AssertHelper.ExpectedException <InvalidOperationException>(() => itemA1.ApplyValuesFrom(itemB1)); }