Writes unit tests, integration tests, and UI tests for Android Kotlin projects. Trigger this skill whenever the user asks to "write tests", "add test coverage", "test this ViewModel", "write an instrumented test", "mock this dependency", or "help me with Espresso / Compose UI testing". Also trigger when the user shares a class with no test file, when a bug fix is made (regression test needed), or when a new UseCase / Repository / ViewModel is created. Proactively suggest test cases when the user shares complex business logic, coroutine chains, or Room queries. Don't wait to be asked — if code is testable and untested, offer to write tests.
