Focused TDD

Treat test-first development as a risk-reduction technique, not a universal ceremony.

Choose the workflow

Inspect the changed behavior, nearby code, existing tests, and repository instructions. State the selected approach briefly before editing.

Use strict RED-GREEN-REFACTOR only when all apply:

• The change has an observable behavioral contract.
• A deterministic automated test can exercise the owning layer.
• The focused test is expected to run quickly enough for repeated feedback.
• Watching the test fail would materially increase confidence in the implementation.

Use regression-first for a confirmed bug when one focused test can reproduce its failure mechanism.

Use proportional validation for exploratory, behavior-preserving, generated, documentation-only, configuration-heavy, primarily visual, or externally dependent work. Add tests after implementation only when they protect meaningful behavior.