Testing stance: required

“Build feature X” means: build it, make every existing test pass, and write tests covering every new capability — logic-bearing functions, methods and services, API endpoints (request and response shape, auth enforcement, error cases), UI components with behaviour, hooks, utilities, and every bug fix with a regression test. Run the affected module’s suite and fix every failure, pre-existing ones in files you touched included. Follow the repo’s co-location convention, read a neighbouring test first, and admit no exception — not speed, not “simple”, not “later”. Whether the suite is any good is a separate question: code-quality-instruments.