Code refactored to adapt it to Strategy Pattern.

csharp/GildedRose.cs

@@ -12,7 +12,16 @@ namespace csharp
             this.Items = Items.Select(i => new ItemWrapperContext(i)).ToList<ItemWrapperContext>();
         }
 
+
         public void UpdateQuality()
+        {
+            for (var i = 0; i < Items.Count; i++)
+            {
+                Items[i].UpdateQuality();
+            }
+        }
+
+        public void UpdateQuality_old()
         {
             for (var i = 0; i < Items.Count; i++)
             {

csharp/Strategy/CategoryStrategiesFactory.cs

@@ -0,0 +1,77 @@
+using System;
+using System.Collections.Generic;
+
+namespace csharp.Strategy
+{
+    class CategoryStrategiesFactory
+    {
+        #region Variables
+
+        static private CategoryStrategiesFactory _strategiesFactory = null;
+
+        #endregion
+
+        #region Constructor
+
+        private CategoryStrategiesFactory() { }
+
+        #endregion
+
+        #region Methods
+
+        public static CategoryStrategiesFactory GetInstance()
+        {
+            if (_strategiesFactory == null)
+            {
+                _strategiesFactory = new CategoryStrategiesFactory();
+            }
+
+            return _strategiesFactory;
+        }
+
+        #endregion
+
+        public List<ICategoryStrategy> GetCategoryStrategies(Item item)
+        {
+            List<ICategoryStrategy> listCategoryStrategies = new List<ICategoryStrategy>();
+
+            if (item.Name == "Aged Brie")
+            {
+                listCategoryStrategies = new List<ICategoryStrategy>()
+                {
+                    new OlderIsBetterStrategy()
+                };
+
+            }
+            else if (item.Name == "Backstage passes to a TAFKAL80ETC concert")
+            {
+                listCategoryStrategies = new List<ICategoryStrategy>()
+                {
+                    new NextExpiredImproveQualityStrategy()
+                };
+            }
+            else if (item.Name == "Sulfuras, Hand of Ragnaros")
+            {
+                listCategoryStrategies = new List<ICategoryStrategy>()
+                {
+                };
+            }
+            else if (item.Name == "Conjured Mana Cake")
+            {
+                listCategoryStrategies = new List<ICategoryStrategy>()
+                {
+                    new TwiceFastDegradeQualityStrategy()
+                };
+            }
+            else
+            {
+                listCategoryStrategies = new List<ICategoryStrategy>()
+                {
+                    new NormalDegradeStrategy()
+                };
+            }
+
+            return listCategoryStrategies;
+        }
+    }
+}

csharp/Strategy/ICategoryStrategy.cs

@@ -0,0 +1,9 @@
+using System;
+
+namespace csharp.Strategy
+{
+    interface ICategoryStrategy
+    {
+        void Update(Item item);
+    }
+}

csharp/Strategy/ItemWrapperContext.cs

@@ -1,10 +1,18 @@
 using System;
+using System.Collections.Generic;
 
 namespace csharp.Strategy
 {
     public class ItemWrapperContext
     {
         #region Variables
+                        
+        private Item _item;
+        private List<ICategoryStrategy> listCategoryStrategies;
+
+        #endregion
+
+        #region Properties
 
         public string Name
         {
@@ -24,9 +32,6 @@ namespace csharp.Strategy
             set { this._item.SellIn = value; }
         }
 
-        //private List<ICategoryStrategy> listCategoryStrategies;
-        private Item _item;
-
         #endregion
 
         #region Constructor
@@ -35,22 +40,21 @@ namespace csharp.Strategy
         {
             this._item = item;
 
-            //listCategoryStrategies = StrategiesFactory.GetInstance().GetCategoryStrategies(item);
+            listCategoryStrategies = CategoryStrategiesFactory.GetInstance().GetCategoryStrategies(item);
         }
 
         #endregion
 
         #region Methods
 
-        //public void UpdateQuality()
+        public void UpdateQuality()
-        //{
+        {
-        //    foreach (ICategoryStrategy categoryStrategyItem in this.listCategoryStrategies)
+            foreach (ICategoryStrategy categoryStrategyItem in this.listCategoryStrategies)
-        //    {
+            {
-        //        categoryStrategyItem.UpdateQuality(this);
+                categoryStrategyItem.Update(this._item);
-        //    }
+            }
-        //}
+        }
 
         #endregion
-
     }
 }

csharp/Strategy/NextExpiredImproveQualityStrategy.cs

@@ -0,0 +1,37 @@
+using System;
+
+namespace csharp.Strategy
+{
+    class NextExpiredImproveQualityStrategy : ICategoryStrategy
+    {
+        public void Update(Item item)
+        {
+            item.SellIn--;
+
+            if (item.SellIn < 0)
+            {
+                item.Quality = 0;
+            }
+            else
+            {
+                int inc = 1;
+
+                if (item.SellIn < 5)
+                {
+                    inc = 3;
+                }
+                else if (item.SellIn < 10)
+                {
+                    inc = 2;
+                }
+
+                item.Quality += inc;
+
+                if (item.Quality > 50)
+                {
+                    item.Quality = 50;
+                }
+            }
+        }
+    }
+}

csharp/Strategy/NormalDegradeStrategy.cs

@@ -0,0 +1,22 @@
+using System;
+
+namespace csharp.Strategy
+{
+    class NormalDegradeStrategy : ICategoryStrategy
+    {
+        public void Update(Item item)
+        {
+            if (item.Quality > 0)
+            {
+                item.Quality--;
+            }
+
+            item.SellIn--;
+
+            if (item.SellIn < 0 && item.Quality > 0)
+            {
+                item.Quality--;
+            }            
+        }
+    }
+}

csharp/Strategy/OlderIsBetterStrategy.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace csharp.Strategy
+{
+    class OlderIsBetterStrategy : ICategoryStrategy
+    {
+        public void Update(Item item)
+        {
+            if (item.Quality < 50)
+            {
+                item.Quality++;
+            }
+
+            item.SellIn--;
+
+            if (item.SellIn < 0 && item.Quality < 50)
+            {
+                item.Quality++;
+            }
+        }
+    }
+}

csharp/Strategy/TwiceFastDegradeQualityStrategy.cs

@@ -0,0 +1,29 @@
+using System;
+
+namespace csharp.Strategy
+{
+    class TwiceFastDegradeQualityStrategy : ICategoryStrategy
+    {
+        public void Update(Item item)
+        {
+            int degrade = 1;
+
+            item.SellIn--;
+
+            if (item.SellIn < 0)
+            {
+                degrade = 2;
+            }
+
+            if (item.Quality > 0)
+            {
+                item.Quality -= degrade;
+            }
+
+            if (item.Quality < 0)
+            {
+                item.Quality = 0;
+            }            
+        }
+    }
+}

csharp/csharp.csproj

@@ -1,5 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <Project ToolsVersion="14.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+  <Import Project="packages\NUnit3TestAdapter.3.8.0\build\net35\NUnit3TestAdapter.props" Condition="Exists('packages\NUnit3TestAdapter.3.8.0\build\net35\NUnit3TestAdapter.props')" />
   <Import Project="$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props" Condition="Exists('$(MSBuildExtensionsPath)\$(MSBuildToolsVersion)\Microsoft.Common.props')" />
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
@@ -65,9 +66,15 @@
     <Compile Include="GildedRose.cs" />
     <Compile Include="GildedRoseTest.cs" />
     <Compile Include="Item.cs" />
+    <Compile Include="Strategy\CategoryStrategiesFactory.cs" />
+    <Compile Include="Strategy\ICategoryStrategy.cs" />
     <Compile Include="Strategy\ItemWrapperContext.cs" />
     <Compile Include="Program.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="Strategy\NextExpiredImproveQualityStrategy.cs" />
+    <Compile Include="Strategy\NormalDegradeStrategy.cs" />
+    <Compile Include="Strategy\OlderIsBetterStrategy.cs" />
+    <Compile Include="Strategy\TwiceFastDegradeQualityStrategy.cs" />
   </ItemGroup>
   <ItemGroup>
     <None Include="App.config" />
@@ -77,6 +84,12 @@
     <Service Include="{82A7F48D-3B50-4B1E-B82E-3ADA8210C358}" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+    <PropertyGroup>
+      <ErrorText>Este proyecto hace referencia a los paquetes NuGet que faltan en este equipo. Use la restauración de paquetes NuGet para descargarlos. Para obtener más información, consulte http://go.microsoft.com/fwlink/?LinkID=322105. El archivo que falta es {0}.</ErrorText>
+    </PropertyGroup>
+    <Error Condition="!Exists('packages\NUnit3TestAdapter.3.8.0\build\net35\NUnit3TestAdapter.props')" Text="$([System.String]::Format('$(ErrorText)', 'packages\NUnit3TestAdapter.3.8.0\build\net35\NUnit3TestAdapter.props'))" />
+  </Target>
   <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
        Other similar extension points exist, see Microsoft.Common.targets.
   <Target Name="BeforeBuild">