Test Runner

Core workflow

1. Detect the language, package manager, and existing test framework before changing anything.
2. Prefer the project's current test stack over introducing a new one.
3. Run the smallest relevant test scope first, then widen coverage after the failure is understood.
4. When fixing bugs, start with a failing test, make the smallest code change that passes, then refactor.
5. After changes, run the narrow test again and then a broader suite if the local workflow supports it.

Framework selection

Use the existing framework when one is already configured. If the project has no test stack, prefer: