So I was trying to write unit tests today and I ran into quite a weird issue. My test failed on a simple constructor test. When I looked at the error message I noticed something odd:
The referenced assembly version in the picture is x.x.x.91, but the current version it should be is a later version. What gives? I tried creating a new unit test project because I thought maybe our unit test project got messed up somehow, but the same error message kept on happening. Another frustrating issue was that when I ran the unit test in debug mode, it passed correctly.
After some searching on the web I ran into this page, which led me to check the project’s code coverage instrumentation section. Sure enough, the project was pointing to an assembly that no longer existed. The red one was the non-existent assembly, the green one is the correct one.
My guess as to why this happened was because initially, the solution was setup to build against Any CPU and this was changed to x86 somewhere along the way. The LocalTestRun.testrunconfig probably never got updated. After pointing to the correct assembly, the test passes and no odd version issues exist.
Incidentally, I asked Greg if his laptop ran into some slowness lately because my hard drive would thrash and adding unit tests literally took me longer than 5 minutes via right-click. Correcting the instrumented assembly corrected this issue as well. One would think that Visual Studio would let the user know that something was up :)
