diff --git a/Refactoring/Store.cs b/Refactoring/Store.cs
index d9a7c78..48fcad6 100644
--- a/Refactoring/Store.cs
+++ b/Refactoring/Store.cs
@@ -32,7 +32,7 @@ public void Purchase(string productId, int quantity)
                 throw new OutOfStockException();
             }
 
-            product.Quantity = product.Quantity - quantity+1;
+            product.Quantity = product.Quantity - quantity;
             user.Balance = user.Balance - product.Price * quantity;
 
             dataManager.SaveUser(user);
diff --git a/UnitTestProject/AuthenticatorTests.cs b/UnitTestProject/AuthenticatorTests.cs
new file mode 100644
index 0000000..562100a
--- /dev/null
+++ b/UnitTestProject/AuthenticatorTests.cs
@@ -0,0 +1,93 @@
+using Newtonsoft.Json;
+using NUnit.Framework;
+using Refactoring;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+namespace UnitTestProject
+{
+	[TestFixture]
+	public class AuthenticatorTests
+	{
+		private User createTestUser(string name, string password, double balance)
+		{
+			User testUser = new User();
+			testUser.Name = name;
+			testUser.Password = password;
+			testUser.Balance = balance;
+
+			return testUser;
+		}
+
+		private List<User> createTestUsers()
+		{
+			List<User> testUsers = new List<User>();
+
+			for (int i = 0; i < 3; i++)
+			{
+				testUsers.Add(createTestUser("TestUser" + i, i.ToString(), 99.99));
+			}
+			
+			return testUsers;
+		}
+
+		[Test]
+		public void Test_GoodAuthenticate()
+		{
+			//Arrange
+			var testUsers = createTestUsers();
+			var authenticator = new Authenticator(testUsers);
+
+			//Act
+			var user = authenticator.Authenticate(testUsers[0].Name, "0");
+
+			//Assert
+			Assert.NotNull(user);
+		}
+
+		[Test]
+		public void Test_BadAuthenticate()
+		{
+			//Arrange
+			var testUsers = createTestUsers();
+			var authenticator = new Authenticator(testUsers);
+			
+			//Act
+			var user = authenticator.Authenticate(testUsers[0].Name, "password");
+
+			//Assert
+			Assert.Null(user);
+		}
+
+		[Test]
+		public void Test_NoUsers()
+		{
+			//Arrange
+			var testUsers = new List<User>();
+			var authenticator = new Authenticator(testUsers);
+
+			//Act
+			var user = authenticator.Authenticate("", "");
+
+			//Assert
+			Assert.Null(user);
+		}
+
+		[Test]
+		public void Test_BlankPassword()
+		{
+			//Arrange
+			var testUsers = createTestUsers();
+			var authenticator = new Authenticator(testUsers);
+
+			//Act
+			var user = authenticator.Authenticate(testUsers[0].Name, "");
+
+			//Assert
+			Assert.Null(user);
+		}
+	}
+}
diff --git a/UnitTestProject/IntegrationTests.cs b/UnitTestProject/IntegrationTests.cs
index f526b8a..ddb4fb9 100644
--- a/UnitTestProject/IntegrationTests.cs
+++ b/UnitTestProject/IntegrationTests.cs
@@ -10,7 +10,7 @@
 namespace UnitTestProject
 {
     [TestFixture]
-    //[Ignore("Disable integration tests")]
+    [Ignore("Disable integration tests")]
     public class IntegrationTests
     {
         private List<User> users;
diff --git a/UnitTestProject/StoreTests.cs b/UnitTestProject/StoreTests.cs
index 9f0b866..99cf35a 100644
--- a/UnitTestProject/StoreTests.cs
+++ b/UnitTestProject/StoreTests.cs
@@ -34,6 +34,19 @@ private Product createTestProduct(string id, string name, double price, int quan
             return testProduct;
         }
 
+		private Store createTestStore(double userBalance, string TEST_PRODUCT_ID, double price, int quantity)
+		{
+			var users = new List<User>();
+			users.Add(createTestUser("Test User", "", userBalance));
+
+			var products = new List<Product>();
+			products.Add(createTestProduct(TEST_PRODUCT_ID, "Product", price, quantity));
+
+			var dataManager = new DataManager(users, products);
+			var store = new Store(users[0], dataManager);
+			return store;
+		}
+
         [Test]
         public void Test_PurchaseThrowsNoErrorForValidFunds()
         {
@@ -60,12 +73,23 @@ public void Test_PurchaseThrowsNoErrorForValidFunds()
         public void Test_PurchaseRemovesProductFromStore()
         {
             //Arrange
+			const string TEST_PRODUCT_ID = "1";
 
-            //Act
+			var users = new List<User>();
+			users.Add(createTestUser("Test User", "", 99.99));
+
+			var products = new List<Product>();
+			products.Add(createTestProduct(TEST_PRODUCT_ID, "Product", 9.99, 10));
+
+			var dataManager = new DataManager(users, products);
+			var store = new Store(users[0], dataManager);
+            
+			//Act
+			store.Purchase(TEST_PRODUCT_ID, 9);
 
             //Assert 
             //(choose the appropriate statement(s))
-            //Assert.AreEqual(1, products[0].Quantity);
+            Assert.AreEqual(1, products[0].Quantity);
             //Assert.AreSame(1, products[0].Quantity);
             //Assert.IsTrue(products[0].Quantity == 1);
         }
@@ -74,22 +98,42 @@ public void Test_PurchaseRemovesProductFromStore()
         public void Test_PurchaseThrowsExceptionWhenBalanceIsTooLow()
         {
             //Arrange
+			const string TEST_PRODUCT_ID = "1";
+			var store = createTestStore(1.00, TEST_PRODUCT_ID, 1.01, 10);
 
             //Act
-
             //Assert
+			Assert.Throws<InsufficientFundsException>(() => store.Purchase(TEST_PRODUCT_ID, 1));
         }
 
         [Test]
+		[ExpectedException(typeof(InsufficientFundsException))]
         public void Test_PurchaseThrowsExceptionWhenBalanceIsTooLowVersion2()
         {
-            //Arrange
+			//Arrange
+			const string TEST_PRODUCT_ID = "1";
+			var store = createTestStore(1.00, TEST_PRODUCT_ID, 1.01, 10);
 
-            //Act
+			//Act
+			store.Purchase(TEST_PRODUCT_ID, 1);
 
             //Assert
         }
 
+		[Test]
+		[ExpectedException(typeof(OutOfStockException))]
+		public void Test_PurchaseThrowsExceptionWhenOutOfStock()
+		{
+			//Arrange
+			const string TEST_PRODUCT_ID = "1";
+			var store = createTestStore(5.00, TEST_PRODUCT_ID, 1.00, 1);
+
+			//Act
+			store.Purchase(TEST_PRODUCT_ID, 2);
+
+			//Assert
+		}
+
 
         // THE BELOW CODE IS REQUIRED TO PREVENT THE TESTS FROM MODIFYING THE USERS/PRODUCTS ON FILE
         //  This is not a good unit testing pattern - the unit test dependency on the file system should
diff --git a/UnitTestProject/UnitTestProject.csproj b/UnitTestProject/UnitTestProject.csproj
index bcf3847..c695f54 100644
--- a/UnitTestProject/UnitTestProject.csproj
+++ b/UnitTestProject/UnitTestProject.csproj
@@ -35,6 +35,7 @@
     <WarningLevel>4</WarningLevel>
   </PropertyGroup>
   <ItemGroup>
+    <Reference Include="Microsoft.VisualStudio.QualityTools.UnitTestFramework, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL" />
     <Reference Include="Newtonsoft.Json, Version=8.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed, processorArchitecture=MSIL">
       <HintPath>..\packages\Newtonsoft.Json.8.0.2\lib\net45\Newtonsoft.Json.dll</HintPath>
       <Private>True</Private>
@@ -73,6 +74,7 @@
     <Compile Include="StoreTests.cs" />
     <Compile Include="IntegrationTests.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
+    <Compile Include="AuthenticatorTests.cs" />
   </ItemGroup>
   <ItemGroup>
     <ProjectReference Include="..\Refactoring\Tusc.csproj">