One of the reason I used to prefer NUnit was that I could run my tests as x86 or x64 depending on what I needed. I was always strange that Microsoft unit testing framework didn’t have this ability.
Luckily for use it seems that Microsoft heard our pain and decided to enable us to run our unit tests in 64bit context.
And its very simple to enable – once you know it’s there.
Just head to the test configuration (yep – Local.testsettings) and under Hosts you can set if to run the tests as a 32bit or 64bit process.