title: Unit Tests from multiple test classes appear to be interleaved
body: <p>I have tests in two separate classes within a MSTest project, each class is (I think) set up properly and each class runs fine but when I run the whole project's tests, some fail.</p>
  
  <p>My two classes both involve setting up some external data but each class is designed to make sure this is in a known state before starting (and to wipe it after finishing). I would have though MSTest might run all methods in a test class in parallel(?), but would run each class in sequence... is this an incorrect assumption?</p>
  
  <p>Edit: I came across this question (<a href="https://stackoverflow.com/questions/2255284/how-does-mstest-determine-the-order-in-which-to-run-test-methods">how does MSTest determine the order in which to run test methods?</a>) It seems to suggest VS may interleave tests from multiple classes in a (seemingly but not actually) random order i.e. it does <em>not</em> run all tests in classA before starting in classB. This is problematic in my case because even if I order my tests within a class, MSTest might still run methods from multiple classes which conflict?</p>