Clean Up after Canceling tests

Question

I'm currently running tests through visual studio. Before all the tests are run, I automatically create a set number of users with know credentials, and at the end of the run I delete those users. However, sometimes I need to cancel my tests midway. In these cases the test never gets the chance to clean up, this means that there is left over fake user info from the test run and may causes the next test run to crash (when it attempts to add user info into the DB). Is there anyway to force visual studio/mstest to run a clean up method even if the test is canceled?

I know one option is to have the test check and make sure that the user info doesn't already exist, and if it does remove it before creating the new users. But this still wouldn't solve the issue of the canceled test run leaving unwanted test data.

Update:

Sorry for the miscommunication, however cleaning up the data at the start of the test is not an option. I'm giving a very simplistic view of the issue, but put simply, I have no easy way of making sure that no test data exists at the start of the test. All clean up must occur at the end of the test.

Answer 1

That is impossible. You better find an alternative solution like using separate database for testing and clean all data before each test run, using fixed set of test users or mark test data with some flag. Check Isolating database data in integration tests article by Jimmy Bogard.

There is no built-in way to change MSTest default behavior. In theory you can write MSTest extension that utilizes TestExecution.OnTestStopping event, but that is not an easy process and it requires registry change. Moreover, a lot of people complain that it is not working.

There also MSTest V2, a new version of MSTest with new extensibility points. But it looks like you can't alter cancel behavior with this points, only write attribute decorators. See Extending MSTest V2.

You can't use AppDomain.CurrentDomain.ProcessExit and Process.GetCurrentProcess().Exited events because cancel seems to kill test run process.

NUnit also doesn't support this at the moment. See related NUnit test adapter Run TearDowns on VS Cancel Test Run issue.

Answer 2

Instead of calling the cleanup function at the end of the test, I call mine at the beginning of each test in order to address this exact problem.