harness:test-driven-development

What problem does it solve?

Prevents shipping unreliable code by forcing a failing test first, then implementing the minimum code needed to make that test pass.

Core Features & Use Cases

• Test-first discipline: Ensures every new feature, bugfix, or refactor is preceded by a failing test that validates real behavior.
• Red-Green-Refactor loop: Drives a strict cycle of watch it fail, implement minimally, verify everything passes, then clean up without adding behavior.
• Acceptance-criteria traceability: Uses the current building feature’s features.json acceptance_criteria as the source for what the tests must cover, and enforces mapping via evaluation rules.

Use case: When you’re implementing a rate-limit change, write tests that directly map to each acceptance criterion (e.g., 6th request rejected with 429 and Retry-After), then implement only what those tests require.

Quick Start

Tell your AI to write a failing test that maps to the current building feature’s acceptance_criteria in features.json, verify the test fails, then implement the smallest code change to make it pass and re-run the test suite.