What problem does it solve?
Writing new features without upfront test coverage often leads to buggy, hard-to-maintain code that breaks unexpectedly during future changes. This Skill enforces a strict test-first workflow to catch issues early and ensure every new behavior works as intended before moving forward.
Core Features & Use Cases
- Strict Red-Green-Refactor Cycle: Follows the canonical test-first loop to prevent speculative code and ensure every line of production code is justified by a failing test.
- Behavior Slicing: Breaks net-new features into small, verifiable test chunks to avoid overwhelming complexity and enable incremental progress.
- Deterministic Verification: Enforces control over time, randomness, I/O, and concurrency to eliminate flaky tests and ensure reliable results.
- Use Case: When adding a new payment processing endpoint to an e-commerce API, use this Skill to write a failing test for successful payment validation first, implement the minimal code to pass it, then refactor for clarity before moving to edge cases like failed payments.
Quick Start
Ask the AI to implement a new user notification feature using strict test-first red-green-refactor workflow, starting with test slices for valid notification triggers and invalid input handling.