Layers Pattern in Practice

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using NUnit.Framework;
using BillsDalLib;
using BillsEntityLib;
using BillsBusinessLogicLib;
using System.Diagnostics;
using System.IO;

namespace TestBillPayManager
{
    [TestFixture(Description = "Test of Logic Layer")]
    public class TestLogic
    {
        private string pathToxml = @"D:\Ahtung\Usefull Projects\WPF\BillPayManager\BillManagerConsole\bin\Debug\archive.xml";
        private string genericDuedate = "Dec 16, 2009 12:00:00 PM";

        [Test(Description = "Singleton object")]
        public void CreateSingletonObject()
        {
            IBillsManager idal1 = BillsManager.GetInstance();
            idal1.Settings = new object[2] { "archive.xml", true };
            IBillsManager idal2 = BillsManager.GetInstance();
            idal2.Settings = new object[2] { "archive.xml", true };
            Assert.AreEqual(idal1.GetHashCode(), idal2.GetHashCode());
            GC.Collect();
        }

        [Test(Description = "Insert bills into the datasource. Read inserted values. Delete inserted values")]
        public void InsertReadDeleteTest()
        {
            List<Bill> list = new List<Bill>();
            Random rand = new Random(list.GetHashCode());
            int numberOfInsertedBills = 50;
            for (int i = 0; i < numberOfInsertedBills; i++)
            {
                Bill bill = new Bill(i.ToString(), DateTime.Parse(genericDuedate), i * rand.Next(25), DateTime.Now, BillStatus.Unpaid, Guid.NewGuid());
                list.Add(bill);
            }
            Bills bills = new Bills(list);
            IBillsManager bll = BillsManager.GetInstance();   //get Datasource manager class
            bll.Settings = new object[2] { pathToxml, true };
            Bills existingBills = bll.Read(DateTime.MinValue, DateTime.MaxValue); //read Existing bills
            Trace.WriteLine(existingBills.ToList().Count());
            bll.Delete(existingBills.GetGuid());    //delete all items from the datasource
            bll.Insert(bills);  //insert items in the datasource
            Bills insertedBills = bll.Read(DateTime.MinValue, DateTime.MaxValue);   //read inserted bills
            Assert.AreEqual(numberOfInsertedBills, insertedBills.ToList().Count());
            bll.Delete(insertedBills.GetGuid());
            GC.Collect();
        }

        [Test(Description = "ReadById and Delete by Id test")]
        public void ReadByIdDeleteByIdTest()
        {
            IBillsManager bll = BillsManager.GetInstance();   //get Datasource manager class
            bll.Settings = new object[2] { pathToxml, true };
            Guid id = Guid.NewGuid();
            string payTo = "Moldtelecom";
            Bills bills = new Bills(new Bill(payTo, DateTime.Parse(genericDuedate), (decimal)125.2, DateTime.Now, BillStatus.Unpaid, id));
            bll.Insert(bills);
            Bill readBill = bll.ReadById(id);
            Assert.AreEqual(payTo, readBill.Name);
            Assert.AreEqual(DateTime.Parse(genericDuedate), readBill.DueDate);
            int deletedItems = bll.Delete(id);
            Assert.AreEqual(1, deletedItems);
            readBill = bll.ReadById(id);
            Assert.AreEqual(null, readBill);
            GC.Collect();
        }
        [Test(Description = "Update bill")]
        public void UpdateBill()
        {
            BillsManager bll = BillsManager.GetInstance();
            bll.Settings = new object[2] { pathToxml, true };
            Guid id = Guid.NewGuid();
            string payTo = "Moldtelecom";
            Bill bill = new Bill(payTo, DateTime.Parse(genericDuedate), (decimal)125.2, DateTime.Now, BillStatus.Unpaid, id);
            Bills bills = new Bills(bill);
            bll.Insert(bills);
            bill.Status = BillStatus.Paid.ToString();
            int updated = bll.Update(id, bill);
            Assert.AreEqual(1, updated);
            Bill readBill = bll.ReadById(id);
            Assert.AreEqual(bill.Name, readBill.Name);
            Assert.AreEqual(bill.Status, readBill.Status);
            GC.Collect();
        }

        [Test(Description = "Create new file test")]
        public void CreateNewFileTest()
        {
            if (File.Exists("newfile.xml"))
                File.Delete("newfile.xml");
            BillsManager ibll = BillsManager.GetInstance();
            ibll.Settings = new object[2] { "newfile.xml", true };
            ibll.Settings = new object[2] { "newnewfile.xml", true };
            Assert.AreEqual(true, File.Exists("newnewfile.xml"));
            File.Delete("newnewfile.xml");
            GC.Collect();
        }

        [Test(Description = "Read from unexisting file")]
        public void ReadFromUnexistingFile()
        {
            if (File.Exists("newfile.xml"))
                File.Delete("newfile.xml");
            IBillsManager ibll = BillsManager.GetInstance();
            ibll.Settings = new object[2] { "newfile.xml", true };
            Bills bills = ibll.Read(DateTime.MinValue, DateTime.MaxValue);
            Assert.AreEqual(0, bills.Items.Count());
        }

        [Test(Description = "Try to create a file which has a bad path")]
        [ExpectedException(typeof(BillManagerException))]
        public void TryToCreateAFileInABadPath()
        {
            if (File.Exists("newfi//le.xml"))
                File.Delete("newfi//le.xml");
            IBillsManager ibll = BillsManager.GetInstance();
            ibll.Settings = new object[2] { "newfi//le.xml", true };
        }
    }
}