I have identified a peculiar behaviour. This is what I did:
- Create an apex class in TWS.
- After creation, add the "@isTest" annotation making it a test class.
When created this way, the created test class always appears in the code coverage window with 0% coverage. While the coverage is correct, this influences the overall code coverage in the Salesforce org (must be 75% on average). Even when I look in the developer console, this class appears as a normal class with no coverage. I believe, something is happening during the creation of the class which makes it impossible for Salesforce to exclude it from the code coverage.