test-driven-development is agent-read markdown (skill) from thoughtbot/rails-consultant: Strict red-green-refactor TDD workflow for implementing features, fixing bugs, or changing behavior in Rails applications. Enforces the discipline of writing a failing test before any production code. Use whenever you want to implement with TDD — whether a new feature, a bugfix, a refactor, or any behavior change..
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What the file says
# Test-Driven Development (TDD)
## Overview
Write the test first. Watch it fail. Write minimal code to pass.
**Core principle:** If you didn't watch the test fail, you don't know if it tests the right thing.
**Violating the letter of the rules is violating the spirit of the rules.**
## The Iron Law
```
NO PRODUCTION CODE WITHOUT A FAILING TEST FIRST
```
Write code before the test? Delete it. Start over.
**No exceptions:**
- Don't keep it as "reference"
- Don't "adapt" it while writing tests
- Don't look at it
- Delete means delete
Implement fresh from tests. Period.
## Outside-In Development
Start every feature with a high-level test that describes behavior from the user's perspective. Run it, read the failure, and let that failure dictate your next move. As failures push you down the stack, write a new failing test at each layer you drop into — never write code for a layer without a failing test at that layer demanding it.
Read `examples/outside-in-testing.md` for a walkthrough of the philosophy and `examples/testing-pyramid.md` for how test types combine into an optimal suite.
### One Change, One Run
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thoughtbot/rails-consultant · skills/standup/SKILL.md · Write a client update — identify what was done, what's next, and surface risks before they become surprises. End of…
addyosmani/agent-skills · skills/test-driven-development/SKILL.md · Drives development with tests using the red-green-refactor loop. Use when implementing any logic, fixing any bug, or…
a5c-ai/babysitter · library/methodologies/superpowers/skills/test-driven-development/SKILL.md · Use when implementing any feature or bugfix, before writing implementation code. Enforces RED-GREEN-REFACTOR cycle.
a5c-ai/babysitter · library/methodologies/rpikit/skills/test-driven-development/SKILL.md · Test-first development practice where test specifications are written before production code, integrated into plan…
a5c-ai/babysitter · library/methodologies/cc10x/skills/test-driven-development/SKILL.md · Strict RED-GREEN-REFACTOR cycle enforcement. Tests are never skipped or deferred. Run mode only, never watch mode. Exit…
ganyuanran/aegis · skills/test-driven-development/SKILL.md · Use when the user explicitly requests strict or test-first TDD, or when the current conversation already contains an…
