Pex and Moles – Isolation and White Box Unit Testing for .NET

Established: February 21, 2007

Pex automatically generates test suites with high code coverage using automated white box analysis. Pex is a Visual Studio add-in for testing .NET Framework applications. Moles supports unit testing by providing isolation by way of detours and stubs. The Moles framework is provided with Pex, or can be installed by itself as a Microsoft Visual Studio add-in.

NEW: IntelliTest in Visual Studio 2015 is the evolution of Pex. IntelliTest is a feature integrated in Visual Studio Enterprise 2015. IntelliTest works together with Fakes.

Download Visual Studio Enterprise 2015 RC with IntelliTest Now!

A Roadmap in Retrospective

IntelliTest in Visual Studio 2015 is the next generation of Pex.

The Fakes Framework in Visual Studio 2012 and 2013 and 2015 is the next generation of Moles & Stubs. Fakes is different from Moles, however, so moving from Moles to Fakes will require some modifications to your code. Moles will not be developed further, so we recommend to migrate to Fakes.

Code Digger for Visual Studio 2012 and 2013 is a lightweight version of Pex that allows you to explore public .NET methods in Portable Libraries directly from the code editor.

Thanks for your support, The Pex and Moles Team.


Portrait of Peli de Halleux

Peli de Halleux

Principal RSDE

Portrait of Nikolaj Bjørner

Nikolaj Bjørner

Partner Researcher