test-driven-development

test-driven-development is a skill for Claude Code, Codex from aaronnat23/disp8ch. It costs 0 tokens per session (157 once invoked), scanned A, original, MIT.

A testing method in which tests describe the required behaviour before the implementation is changed. TDD means test-driven development.

In plain words
What is it for?
Use it to write a small failing test, make the minimum implementation change, run related tests, and refactor after the behaviour is covered.
Why use it?
It makes the target behaviour explicit and helps prevent regressions by keeping the change tied to a passing test.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to write a small failing test, make the minimum implementation change, run related tests, and refactor after the behaviour is covered.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/aaronnat23/disp8ch/test-driven-development
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.

Any agent
npx skills add aaronnat23/disp8ch --skill test-driven-development
Clone the repo
git clone --depth 1 https://github.com/aaronnat23/disp8ch

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/aaronnat23/disp8ch/test-driven-development.svg)](https://agentmods.dev/skills/aaronnat23/disp8ch/test-driven-development)
Your own site
<a href="https://agentmods.dev/skills/aaronnat23/disp8ch/test-driven-development"><img src="https://agentmods.dev/badge/skills/aaronnat23/disp8ch/test-driven-development.svg" alt="Measured on agentmods" height="20"></a>
Per session 0 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 157 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 5.1 $0.00000 $0.00157
Opus 5 $0.00000 $0.00078
Sonnet 5 $0.00000 $0.00031
Haiku 4.5 $0.00000 $0.00016

Measured 4d ago against content hash 614a3c5daac6, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, 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 4d 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.

optional-skills/test-driven-development/SKILL.md · 21 lines

What it actually says

Test-Driven Development

Use tests to define the target behavior before changing implementation.

Use when

  • A change has a clear acceptance condition that can be encoded first.
  • A regression needs a durable test instead of a one-off fix.

Workflow

  1. Write or identify the smallest failing test that captures the requirement.
  2. Keep the first test narrow so the failure is easy to interpret.
  3. Make the minimal code change needed to turn the test green.
  4. Run adjacent tests that cover the same boundary, not just the single happy path.
  5. Refactor only after behavior is locked by passing tests.

Deliverable

  • New or updated failing test.
  • Minimal implementation change.
  • Final passing test evidence.
  • Any gaps that still need broader coverage.
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. 4d ago First seen · 21 lines · 0 tokens per session scan A 614a3c5daac6

Subscribe to this mod's changes

test-driven-development is a skill published in the GitHub repository aaronnat23/disp8ch (99 stars, last pushed 5d ago), licensed MIT. It costs nothing until one of its globs matches a file; then it loads 157 tokens. 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 2026-09-03.

Related

Other skills, from other repositories

taiyi-dev

A software-development stage that implements planned tasks using test-driven development, or TDD: write a failing test, make it pass, then improve the code. It checks the task plan, dependencies, file boundaries, and required completion evidence.

Dong90/oh-my-taiyiforge · 21 tokens

tdd

A Test-Driven Development guide. TDD means writing a failing test first, adding the smallest implementation that passes it, and then improving the code while keeping the tests passing.

Insajin/autopus-adk · 11 tokens

spec-driven-development

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magnus919/agent-skills · 165 tokens

debugging

A structured method for finding and fixing software bugs. It starts by writing a test that reproduces the failure, then investigates its underlying cause before making a small fix.

Insajin/autopus-adk · 16 tokens

blueprint

Converts an approved spec into a TDD task plan with a parallelism map (PARALLEL vs SEQUENTIAL), saved to .workspace/shared/plans/. Use after a spec is approved, before implementation.

Alexander-Tyagunov/magician · 45 tokens

ward

TDD engine and enforcer — red/green/refactor, one behavior at a time. Use while implementing any feature or bugfix, or to execute a specific blueprint task with TDD.

Alexander-Tyagunov/magician · 41 tokens