Ensure Isolation Between the Tests

There are few reasons to ensure isolation. One of them is to allow different tests to occur simultaneously, but even if you run all the tests linearly, some tests may affect other tests unintentionally. And this is also something that you have to consider and to make sure that you do the proper isolation between the tests. Some techniques for isolation may be to clean all the data between the tests or to have separate environments,. Separate databases, separate tenants if you're working on a multi-tenant application, for example.