Added Writing Tests Section to Testing.md

# Running Tests

# Writing Tests

Windows Device Portal Wrapper (WDPW) tests are run against mock data so that a windows device is not required to run the tests.

1.	Create a Unit Test class in the Unit Test Project

  ![addunittest](https://cloud.githubusercontent.com/assets/1520739/17310088/225af006-57f7-11e6-834c-7735b7270d85.png)

2.	Have the test class inherit from the BaseTests class which will automatically establish your mock connection (the constructor and TestContext can be removed)

  ```c#

 /// <summary>

  /// Summary description for DemoTest

  /// </summary>

  [TestClass]

  public class DemoTest : BaseTests

  {

  }

  ```

  a. If you are writing a device specific version test then override the PlatformType, the FriendlyOperatingSystemVersion used to specify where mock files are stored/named, and the OperatingSystemVersion to be used when validating the OS’s actual version number.

  ```c#

 /// <summary>

/// Gets the Platform type these tests are targeting.

/// </summary>

protected override DevicePortalPlatforms PlatformType

{

  get { return DevicePortalPlatforms.XboxOne;}

}

/// <summary>

/// Gets the friendly OS Version these tests are targeting.

/// </summary>

protected override string FriendlyOperatingSystemVersion

{

  get { return "rs1_xbox_rel_1608";}

}

/// <summary>

/// Gets the OS Version these tests are targeting.

/// </summary>

protected override string OperatingSystemVersion

{

  get { return "14385_1002_amd64fre_rs1_xbox_rel_1608_160709_1700";}

}

  ```

3.	Define void methods with no parameters tagged with “testMethod” for each test case you want to run

  ```c#

  [TestMethod]

  public void TestMethod1()

  {

    //

    // TODO: Add test logic here

    //

  }

  ```

4. Each test should start with a call to TestHelpers.MockHttpResponder.AddMockResponse to prepare a mock response for a specified enpoint in one of three ways:

  a. Default mock

  Use mock data from the MockData\Defaults\<endpoint>_Default.dat file.

  ```c#

  TestHelpers.MockHttpResponder.AddMockResponse(DevicePortal.KnownFoldersApi, response, HttpMethods.Get);

  ```

  b. Version specific mock

  Use mock data from the MockData\<platform>\<friendly OS version>\<endpoint>_<platform>_<friendly OS version>.dat file

  ```c#

  TestHelpers.MockHttpResponder.AddMockResponse(DevicePortal.KnownFoldersApi, this.PlatformType, this.FriendlyOperatingSystemVersion, HttpMethods.Get);

  ```

  c. Provided response

  Use a response object as a mock.

  ```c#

  TestHelpers.MockHttpResponder.AddMockResponse(DevicePortal.GetFilesApi, response, HttpMethods.Get);

  ```

5. Have the test methods use TestHelpers.Portal to call DevicePortal methods and then Assert methods to validate results

  ```c#

  Task<string> getNameTask = TestHelpers.Portal.GetDeviceName();

  getNameTask.Wait();

  Assert.IsNotNull(TestHelpers.Portal.OperatingSystemVersion);

  ```

6. After building the test right click on it in the test explorer and select “Debug Selected Tests” to be able to hit selected break points as it runs.

  ![debugselectedtests](https://cloud.githubusercontent.com/assets/1520739/17310093/27a33636-57f7-11e6-8cab-45620c167dcf.png)

# Collecting Data for Tests