XUnit–Writing test output

I recently started using XUnit. I’m still discovering what is possible using this unit test framework.
One of the things I had to discover was how to write log messages during my tests.  I could fall back to using Trace.WriteLine or Console.WriteLine but that is not the best solution. XUnit allows you to capture test output using a special interface called ITestOutputHelper. In order to use this, just add a constructor argument for this interface and store it inside a variable inside your test class:

	public class MailTests : IDisposable
	{
	private readonly ITestOutputHelper _testOutputHelper;
	public MailValidationTests(ITestOutputHelper testOutputHelper)
	{
	_testOutputHelper = testOutputHelper;
	}
	[Fact]
	public void Mail_MustHaveASubject()
	{
	}
	}

view raw MailTests.cs hosted with ❤ by GitHub

Now if you call the ITestOutputHelper.WriteLine method, the output is captured and available inside your test output: