// Add record to a new log file
        // becausecurrent log file has reached maxEntriesPerFile
        public void AddRecord_LinesHasReachMaxEntriesPerFileTest()
        {
            LibrarianshipImmutable librarian =
                new LibrarianshipImmutable(3);

            FileContent file = new FileContent(
                "LibraryLog_0001.txt",
                new[] {
                "1;Arthur Jackson;Responsive Web Design;9/26/2016",
                "2;Maddox Webb;AngularJS by Example;9/27/2016",
                "3;Mel Fry;Python Machine Learning;9/28/2016"
            });

            FileAction action = librarian.AddRecord(
                file,
                "Haiden Brown",
                "Practical Data Science",
                new DateTime(2016, 9, 29, 0, 0, 0));

            Assert.AreEqual(
                ActionType.Create,
                action.Type);
            Assert.AreEqual(
                "LibraryLog_0002.txt",
                action.FileName);
            CollectionAssert.AreEqual(
                new[] {
                "1;Haiden Brown;Practical Data Science;9/29/2016"
            },
                action.Content);
        }
        // Add record to existing log file
        // but the lines is lower then maxEntriesPerFile
        public void AddRecord_LinesIsLowerThanMaxEntriesPerFileTest()
        {
            LibrarianshipImmutable librarian =
                new LibrarianshipImmutable(5);

            FileContent file = new FileContent(
                "LibraryLog_0001.txt",
                new[] {
                "1;Arthur Jackson;Responsive Web Design;9/26/2016"
            });

            FileAction action = librarian.AddRecord(
                file,
                "Maddox Webb",
                "AngularJS by Example",
                new DateTime(
                    2016, 9, 27, 0, 0, 0));

            Assert.AreEqual(
                ActionType.Update,
                action.Type);
            Assert.AreEqual(
                "LibraryLog_0001.txt",
                action.FileName);
            CollectionAssert.AreEqual(
                new[] {
                "1;Arthur Jackson;Responsive Web Design;9/26/2016",
                "2;Maddox Webb;AngularJS by Example;9/27/2016"
            },
                action.Content);
        }