With more features being pushed down into less expensive versions, Microsoft is always looking for ways to justify the hefty price tag for Visual Studio Enterprise Edition. New for this year, the headline feature is “live unit testing”.

For a while now Visual Studio has had the option to automatically run unit tests after each build. Live Unit Testing takes the next step and runs your tests as you type. You don’t even have to save the file; as soon as you change the code the unit tests start running.

Live code coverage is provided, with indicators for pass/fail/not-tested. An overlay on the icon indicates that the test is being re-run. Clicking on the icon will list the associated tests and the mouse-over will show the stack trace.

VS Live Unit Testing supports NUnit, xUnit, and MSTest, although you’ll need to install preview versions of the latter two .NET Core, Universal Windows Apps and Xamarin are not currently supported. Manish Jayaswal of Microsoft writes, “Adding support for .NET Core is in the roadmap. However, we do not have a timeline for it yet.”

According to Tanner Gooding, also from Microsoft, part of the reason for the delay is that the PDB symbols file for .NET Core has changed. While originally designed for Windows only, the new cross-platform PDB format had undergone major revisions.

If this feature sounds familiar, it is because Microsoft isn’t the first one to offer it. NCrunch by Remco Software Ltd. essentially works the same way. But being a much older product, NCrunch has had time to refine its IDE integration, and detailed error analysis is just a click or two away. NCrunch also integrates distributed processing and performance metrics, which are separate tools in Visual Studio Enterprise.

While a true price comparison can’t be made, NCrunch is also more affordable for the budget conscious developer, with prices starting at $159 USD for the individual and $289 USD/person for a company license with a discount for upgrading previous versions.