Test Framework
Under Code, Test Framework covers libraries and tools whose primary job is to author, organize, and run automated tests, runners, assertion libraries, mocks, and chart/template testers. This is not Unit Testing or Integration Testing themselves (those are Technique notes); it is the concrete software you pick to implement them.
Sibling subcategories: Language, Library, and Framework (application stacks). Tag an item here when the product exists mainly to support test execution (e.g. Helm Unittest for Helm Chart templates, TestContainer for integration dependencies) not when testing is a side feature of a larger platform.