nunit.md

+## Add NUnit Tests
+
+### Add Nunit test adapter
+1.  Choose **Tools > Extensions and Updates**
+2.  In the **Extensions and Updates** dialog box, expand the **Online** category and then **Visual Studio Marketplace**. Then, choose **Tools > Testing**.
+2.  Select the **NUnit test adapter** and then choose **Download.**
+### Add Tests
+
+1.  Create a class library project and add it to your solution.
+
+    For convinience name it like your main project and add **.Tests** as a suffix.
+    ![alt text](images/create_class_library.png "Select Class Library")
+
+2.  Install the plug-in. In **Solution Explorer**, select the class library project, and then choose **Manage NuGet Packages** from its right-click or context menu.
+
+    ![alt text](images/add_a_package.png "Add a package")
+
+3.  In the **NuGet Package Manager** window, search for and select the plug-in (NUnit), and then choose **Install**.
+    ![alt text](images/select_framework.png "Select Project")
+
+    The framework is now referenced in your project under **References**.
+
+4.  From the class library project's **References** node, select **Add Reference**.
+
+    ![alt text](images/add_a_reference.png "Add a reference")
+
+5. In the **Reference Manager** dialog box, select the project that contains the code you'll test.
+
+    ![alt text](images/select_project.png "Select Project")
+
+6. Code your unit test.
+    
+    ![alt text](images/test_code.png "Test Code")