Solution for parts 1-3

DesignPatternsSolution/DesignPatternsSolution.sln

@@ -1,11 +1,11 @@
 
 Microsoft Visual Studio Solution File, Format Version 12.00
-# Visual Studio 14
-VisualStudioVersion = 14.0.24720.0
+# Visual Studio 2013
+VisualStudioVersion = 12.0.21005.1
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Exercise", "Exercise\Exercise.csproj", "{EA98A53A-F8CD-4539-9E57-1FEF2D64F13A}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Execise.Tests", "Execise.Tests\Execise.Tests.csproj", "{464FBD03-CA8B-4926-8F69-66726819DA02}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Exercise.Tests", "Execise.Tests\Exercise.Tests.csproj", "{464FBD03-CA8B-4926-8F69-66726819DA02}"
 EndProject
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Documents", "Documents", "{8C88EFFA-EC68-42ED-A482-A7B8964538E8}"
 	ProjectSection(SolutionItems) = preProject

DesignPatternsSolution/Execise.Tests/Execise.Tests.csproj → DesignPatternsSolution/Execise.Tests/Exercise.Tests.csproj

@@ -8,14 +8,15 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>Execise.Tests</RootNamespace>
     <AssemblyName>Execise.Tests</AssemblyName>
-    <TargetFrameworkVersion>v4.5.2</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <ProjectTypeGuids>{3AC096D0-A1C2-E12C-1390-A8335801FDAB};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}</ProjectTypeGuids>
     <VisualStudioVersion Condition="'$(VisualStudioVersion)' == ''">10.0</VisualStudioVersion>
     <VSToolsPath Condition="'$(VSToolsPath)' == ''">$(MSBuildExtensionsPath32)\Microsoft\VisualStudio\v$(VisualStudioVersion)</VSToolsPath>
     <ReferencePath>$(ProgramFiles)\Common Files\microsoft shared\VSTT\$(VisualStudioVersion)\UITestExtensionPackages</ReferencePath>
     <IsCodedUITest>False</IsCodedUITest>
     <TestProjectType>UnitTest</TestProjectType>
+    <TargetFrameworkProfile />
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <DebugSymbols>true</DebugSymbols>

DesignPatternsSolution/Execise.Tests/UnitTests.cs

@@ -1,7 +1,7 @@
 using Exercise;
 using Microsoft.VisualStudio.TestTools.UnitTesting;
 
-namespace Execise.Tests
+namespace Exercise.Tests
 {
     [TestClass]
     public class UnitTests
@@ -12,18 +12,28 @@ public void LibraryShouldBeSingleton()
         {
             //check that when you create a Library instance second time, 
             //you get exactly the same instance as for a very first time
+            Library library1 = Library.getInstance();
+            Library library2 = Library.getInstance();
+
+            Assert.AreEqual(library1, library2);
         }
 
         //test that an book was registered successfully by checking the returned Id value is not -1
         [TestMethod]
         public void BookShouldRegister()
         {
+            Book book = new Book("Mr. Smart", "My Book", 1985, 20);
+            int result = RegistrationRepository.Register(book);
+            Assert.AreNotEqual(-1, result);
         }
 
         //test that an customer was registered successfully by checking the returned Id value is not -1
         [TestMethod]
         public void CustomerShouldRegister()
         {
+            Customer customer = new Customer("John Doe", "123 Fourth St.");
+            int result = RegistrationRepository.Register(customer);
+            Assert.AreNotEqual(-1, result);
         }
 
         //test that a book can be borrowed
@@ -32,7 +42,17 @@ public void CanBorrowBook()
         {
             //create a borrowable book with available amount more than one. 
             //Run BorrowOne method of the BookBorrowable instance. Check that total amount was reduced by one.
-
-        }       
+
+            Book myBook = new Book("Glen Miller", "My Book", 1990, 50);
+
+            int oldCount = myBook.AvailableAmount;
+
+            Borrowable bookBorrowable = new Borrowable(null, new BorrowOne(myBook));
+            bookBorrowable.BorrowOne();
+
+            int newCount = myBook.AvailableAmount;
+
+            Assert.AreEqual(oldCount - 1, newCount);
+        }
     }
 }

DesignPatternsSolution/Exercise/BookBorrowable.cs

@@ -1,7 +1,48 @@
 namespace Exercise
 {
-    public class BookBorrowable 
+    public abstract class ABorrowable
     {
-
+        public virtual void BorrowOne() { }
+        protected BorrowOne borrowOneProcedure;
+        public ABorrowable(BorrowOne borrowOneProcedure)
+        {
+            this.borrowOneProcedure = borrowOneProcedure;
+        }
+    }
+
+    public class Borrowable : ABorrowable
+    {
+        private ABorrowable borrowableToExtend;
+
+        public Borrowable(ABorrowable borrowable, BorrowOne borrowOneProcedure)
+            : base(borrowOneProcedure)
+        {
+            borrowableToExtend = borrowable;
+        }
+
+        public override void BorrowOne()
+        {
+            if (borrowableToExtend != null)
+            {
+                borrowableToExtend.BorrowOne();
+            }
+
+            borrowOneProcedure.borrowOne();
+        }
+    }
+
+    public class BorrowOne
+    {
+        private LibObject libObject;
+
+        public BorrowOne(LibObject libObject)
+        {
+            this.libObject = libObject;
+        }
+
+        public void borrowOne()
+        {
+            this.libObject.AvailableAmount--;
+        }
     }
 }

DesignPatternsSolution/Exercise/Exercise.csproj

@@ -9,9 +9,10 @@
     <AppDesignerFolder>Properties</AppDesignerFolder>
     <RootNamespace>Exercise</RootNamespace>
     <AssemblyName>Exercise</AssemblyName>
-    <TargetFrameworkVersion>v4.5.2</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v4.5</TargetFrameworkVersion>
     <FileAlignment>512</FileAlignment>
     <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
+    <TargetFrameworkProfile />
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <PlatformTarget>AnyCPU</PlatformTarget>

DesignPatternsSolution/Exercise/Item.cs

@@ -10,13 +10,23 @@ public Item(int amount, int year)
         }
     }
 
-    public class Book : Item
+    public class Book : Item, IRegistarable
     {
-        public Book(string author, string title, int year, int amount) : base(amount, year)
+        public Book(string author, string title, int year, int amount)
+            : base(amount, year)
         {
             NameOrTitle = title;
             Author = author;
         }
         public string Author { get; set; }
+
+        public RegisteredObject GetRegistrationInfo()
+        {
+            RegisteredObject registeredObject = new RegisteredObject();
+            registeredObject.Info = this.NameOrTitle;
+            registeredObject.AvailableAmount = this.AvailableAmount;
+
+            return registeredObject;
+        }
     }
 }

DesignPatternsSolution/Exercise/Library.cs

@@ -2,9 +2,14 @@
 {
     public class Library
     {
-        //implement Singleton to make sure only one library will exist
+        private static Library library = new Library();
 
-
+        private Library() { }
+
+        public static Library getInstance()
+        {
+            return library;
+        }
 
         //Implement Register method by utilizing RegistrationRepository (complete missing parts)
         public int Register()

DesignPatternsSolution/Exercise/Person.cs

@@ -2,7 +2,7 @@
 
 namespace Exercise
 {
-    public class Customer : LibObject
+    public class Customer : LibObject, IRegistarable
     {
         public string Address { get; set; }
         public DateTime RegisteredAt { get; set; }
@@ -19,5 +19,14 @@ public void SetId(int id)
         {
             ObjectId = id;
         }
+
+        public RegisteredObject GetRegistrationInfo()
+        {
+            RegisteredObject registeredObject = new RegisteredObject();
+            registeredObject.Info = this.NameOrTitle;
+            registeredObject.AvailableAmount = this.AvailableAmount;
+
+            return registeredObject;
+        }
     }
 }