ListModel_should.cs

using System.Collections.Generic;
using NUnit.Framework;

namespace TodoApplication
{
    [TestFixture]
    public class ListModel_Should
    {
        [Test]
        public void AddItems()
        {
            var model = new ListModel<string>(20);
            model.AddItem("a");
            model.AddItem("bb");
            model.AddItem("ccc");
            Assert.AreEqual(new List<string>{"a", "bb", "ccc"}, model.Items);
        }

        [Test]
        public void RemoveFromTheEnd()
        {
            var model = new ListModel<string>(20);
            model.AddItem("a");
            model.AddItem("bb");
            model.AddItem("ccc");
            model.RemoveItem(2);
            Assert.AreEqual(new List<string> { "a", "bb" }, model.Items);
        }

        [Test]
        public void RemoveFromTheBeginning()
        {
            var model = new ListModel<string>(20);
            model.AddItem("a");
            model.AddItem("bb");
            model.AddItem("ccc");
            model.RemoveItem(0);
            Assert.AreEqual(new List<string> { "bb", "ccc" }, model.Items);
        }

        [Test]
        public void RemoveFromTheMiddle()
        {
            var model = new ListModel<string>(20);
            model.AddItem("a");
            model.AddItem("bb");
            model.AddItem("ccc");
            model.RemoveItem(1);
            Assert.AreEqual(new List<string> { "a", "ccc" }, model.Items);
            model.Undo();
            Assert.AreEqual(new List<string> { "a", "bb", "ccc" }, model.Items);
        }

        [Test]
        public void RemoveAndUndoAllItems()
        {
            var model = new ListModel<string>(20);
            model.AddItem("a");
            model.AddItem("bb");
            model.AddItem("ccc");
            model.RemoveItem(0);
            model.RemoveItem(0);
            model.RemoveItem(0);
            Assert.AreEqual(new List<string>(), model.Items);
            model.Undo();
            model.Undo();
            model.Undo();
            Assert.AreEqual(new List<string> { "a", "bb", "ccc" }, model.Items);
        }

        [Test]
        public void UndoAddOperations()
        {
            var model = new ListModel<string>(20);
            model.AddItem("a");
            Assert.AreEqual(true, model.CanUndo());
            model.Undo();
            Assert.AreEqual(0, model.Items.Count);
        }

        [Test]
        public void NotUndo_WhenEverythingIsUndone()
        {
            var model = new ListModel<string>(20);
            model.AddItem("a");
            model.AddItem("bb");
            model.Undo();
            model.Undo();
            Assert.AreEqual(false, model.CanUndo());
        }

        [Test]
        public void Add_AfterUndo()
        {
            var model = new ListModel<string>(20);
            model.AddItem("a");
            model.AddItem("bb");
            model.Undo();
            model.Undo();
            model.AddItem("qq");
            Assert.AreEqual(new List<string> { "qq" }, model.Items);
        }

        [Test]
        public void Undo_AfterRemove()
        {
            var model = new ListModel<string>(20);
            model.AddItem("a");
            model.AddItem("bb");
            model.RemoveItem(1);
            model.Undo();
            Assert.AreEqual(new List<string> { "a", "bb" }, model.Items);
        }

        [Test]
        public void Remove_AfterUndo()
        {
            var model = new ListModel<string>(20);
            model.AddItem("a");
            model.AddItem("bb");
            model.Undo();
            model.RemoveItem(0);
            Assert.AreEqual(0, model.Items.Count);
        }

        [Test]
        public void NotUndo_WhenUndoLimitIsReached()
        {
            var model = new ListModel<string>(2);
            model.AddItem("a");
            model.AddItem("bb");
            model.RemoveItem(1);
            model.Undo();
            model.Undo();
            Assert.AreEqual(false, model.CanUndo());
            Assert.AreEqual(new List<string> {"a"}, model.Items);
        }

        [Test]
        public void CanUndo_ReturnsFalse_WhenUndoLimitIsReached()
        {
            var model = new ListModel<string>(1);
            Assert.AreEqual(false, model.CanUndo());
            model.AddItem("a");
            model.AddItem("bb");
            model.Undo();
            Assert.AreEqual(false, model.CanUndo());
            model.AddItem("ccc");
            Assert.AreEqual(true, model.CanUndo());
        }

        [Test]
        public void CanUndo_ReturnsFalse_WhenUndoLimitIsZero()
        {
            var model = new ListModel<string>(0);
            Assert.AreEqual(false, model.CanUndo());
            model.AddItem("a");
            model.AddItem("bb");
            Assert.AreEqual(false, model.CanUndo());
        }
    }
}