Why do my tests fail when run together, but pass individually?

Question

When I write a test in Visual Studio, I check that it works by saving, building and then running the test it in Nunit (right click on the test then run).

The test wo

Answer 1

Such a situation normally occurs when the unit tests are using shared resources/data in some way.

1. It can also happen if your system under test has static fields/properties which are being leveraged to compute the output on which you are asserting.
2. It can happen if the system under test is being shared (static) dependencies.