mission-tdd

Implement a behavior change by writing a failing test first, then minimum code.

Updated May 22, 2026

Search Tags:#tdd #regression testing #test-first #code change #behavior verification #mission orchestration

Ready to run

npx skills add https://github.com/MathieuDoyon/mission --skill mission-tdd

💬 Prompt for ChatGPT / Claude Chat▼

Please help me install this Agent Skill.
Skill: mission-tdd
Source: https://github.com/MathieuDoyon/mission/tree/main/.claude/skills/mission-tdd
Command: npx skills add https://github.com/MathieuDoyon/mission --skill mission-tdd

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve?

mission-tdd helps developers implement a single behavior change safely and correctly by forcing a failing test first, then the minimum code needed to pass it.

Core Features & Use Cases

Test-first behavior change: turns a proposed behavior into a new or updated test and verifies it fails for the right reason.
Minimum implementation: adds only the smallest code change required to make the test pass, avoiding unrelated refactors.
Verification discipline: runs the focused test command and re-runs the closest related test group to catch regressions before reporting back.

Quick Start

Ask an orchestrator to invoke mission-tdd to implement “the next missing behavior X with verification,” and let it produce a mission-report with test-first results.

Frequently Asked Questions about mission-tdd

High-intent search queries and answers about installing and using this skill.

FAQPage Schema

How do I implement a test-driven behavior change without introducing unrelated refactors?▼

Test-driven behavior change is implemented by writing a failing test first, then applying only the minimum code required to pass it. This one-change-per-invocation discipline avoids unrelated refactors and ensures the behavior gap is safely closed with verification.

What is the best way to verify a single behavior gap identified during a code review?▼

The best way to verify a behavior gap is using test-first development to turn the proposed behavior into a failing test, adding the smallest code change to pass it, and running the closest related test group to catch regressions before reporting back.

Can I run focused test commands to catch regressions when making small single-scope code upgrades?▼

Yes, focused test commands are run to verify the new behavior, and the closest related test group is re-run to catch regressions. This verification discipline ensures small single-scope upgrades maintain existing functionality during mid-mission iterations.

When do I need test-first development for mid-mission code iterations?▼

Test-first development is needed for mid-mission iterations when an existing plan or review identifies a concrete behavior gap requiring verification. It produces a structured mission-report containing acceptance criteria, edited file paths, and test results.

Does test-first behavior change require a mission orchestration framework to work?▼

No specific framework is required, but an orchestrator can invoke the test-first behavior change process. You ask the orchestrator to implement the next missing behavior with verification, and it produces a mission-report with test-first results and recommended next routing.

What are the limitations of applying minimum code changes to pass a failing test?▼

The limitation is that it strictly maintains one-change-per-invocation discipline, meaning it is not suitable for large refactors. It is designed exclusively for small, single-scope upgrades and mid-mission behavior verification tasks.