test-driven-development

test-driven-development is a skill for Claude Code, Codex from J-Pster/Psters_AI_Workflow. It costs 27 tokens per session (149 once invoked), scanned A, original, MIT.

An optional test-first workflow called test-driven development, or TDD. It uses a repeating cycle: write a failing test, make the smallest change that passes it, then clean up the code.

In plain words
What is it for?
Writing tests before implementation when the user explicitly asks for TDD or test-first development, then implementing and refining the tested behaviour.
Why use it?
It provides a small feedback loop for checking that a change behaves as intended while keeping the work focused.

Skill for Claude CodeCodex

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add skills/j-pster/psters_ai_workflow/test-driven-development
Any agent
npx skills add J-Pster/Psters_AI_Workflow --skill test-driven-development
Clone the repo
git clone --depth 1 https://github.com/J-Pster/Psters_AI_Workflow

Made for: Claude Code, Codex.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for test-driven-development

README.md
[![agentmods](https://agentmods.dev/badge/skills/j-pster/psters_ai_workflow/test-driven-development.svg)](https://agentmods.dev/skills/j-pster/psters_ai_workflow/test-driven-development)
Your own site
<a href="https://agentmods.dev/skills/j-pster/psters_ai_workflow/test-driven-development"><img src="https://agentmods.dev/badge/skills/j-pster/psters_ai_workflow/test-driven-development.svg" alt="Measured on agentmods" height="20"></a>
Per session 27 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 149 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00027 $0.00149
Opus 5 $0.00014 $0.00075
Sonnet 5 $0.00005 $0.00030
Haiku 4.5 $0.00003 $0.00015

Measured 5d ago against content hash 2daf43b17a73, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

test-driven-development scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 5d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

plugins/psters-ai-workflow/skills/test-driven-development/SKILL.md · 25 lines

What it actually says

Test-Driven Development (Optional)

This skill is opt-in.

Activation rule

Apply only when the user explicitly asks for TDD/tests (e.g., "use TDD", "write tests first", "test-first").

Core loop

  1. Red: write a failing test for the target behavior.
  2. Green: implement minimal code to pass.
  3. Refactor: clean implementation while keeping tests green.

Guardrails

  • Keep scope small per cycle.
  • Avoid broad speculative test suites.
  • Preserve existing project rules when tests are not desired globally.
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 5d ago First seen · 25 lines · 27 tokens per session scan A 2daf43b17a73

Subscribe to this mod's changes

test-driven-development is a skill published in the GitHub repository J-Pster/Psters_AI_Workflow (290 stars, last pushed 5mo ago), licensed MIT. It adds 27 tokens to every session and 149 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.