What problem does it solve? Executing a multi-phase implementation plan while keeping tests ahead of code is hard to do consistently — developers often write code first and retrofit tests, losing the design benefits of TDD. This Skill drives an approved plan from context/changes/<change-id>/plan.md to completion one phase at a time, enforcing the failing-test-first discipline and tracking progress in a single source of truth. ## Core Features & Use Cases - Red-Green-Refactor Loop: For each phase, writes a failing test (RED), implements the minimal code to pass (GREEN), then refactors while keeping the suite green. - TDD Eligibility Gate: Before each phase, checks whether implementation already exists (stops and redirects to /10x-implement) and whether the phase is meaningfully test-driven (redirects scaffolding, config, or visual phases). - Progress Tracking & Commit Ritual: Mutates the plan's canonical ## Progress section, runs a manual verification gate, and creates one Conventional-Commits commit per phase with SHA write-back. - Use Case: You have an approved plan for a new API feature with 4 phases. Run /10x-tdd my-feature and each phase is driven test-first, with per-phase commits and checkpoints, while non-TDD'able phases are handed off to /10x-implement. ## Quick Start Ask the assistant to run /10x-tdd with your change-id, for example "drive the oauth-login plan test-first starting at phase 1".
