test-driven-development-quick

test-driven-development-quick is a skill for Claude Code from jaktestowac/awesome-copilot-for-testers. It costs 108 tokens per session (1,694 once invoked), scanned A, original, MIT.

A short guide to test-driven development, or TDD: write one failing test, add the smallest code that passes it, then clean up the code while tests remain green. It is intended for one behavior or a small bug fix.

In plain words
What is it for?
Building a small feature test-first, reproducing and fixing a bug with a failing test, or adding a focused rule to code that already has tests.
Why use it?
It keeps small changes tied to a clearly stated expected behavior and catches regressions early. The compact cycle avoids writing a large batch of tests for behavior that has not been implemented yet.

Skill for Claude Code

Written for Claude Code: user-invocable in frontmatter.

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/jaktestowac/awesome-copilot-for-testers/test-driven-development-quick
Any agent
npx skills add jaktestowac/awesome-copilot-for-testers --skill test-driven-development-quick
Clone the repo
git clone --depth 1 https://github.com/jaktestowac/awesome-copilot-for-testers

Made for: Claude Code.

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-quick

README.md
[![agentmods](https://agentmods.dev/badge/skills/jaktestowac/awesome-copilot-for-testers/test-driven-development-quick.svg)](https://agentmods.dev/skills/jaktestowac/awesome-copilot-for-testers/test-driven-development-quick)
Your own site
<a href="https://agentmods.dev/skills/jaktestowac/awesome-copilot-for-testers/test-driven-development-quick"><img src="https://agentmods.dev/badge/skills/jaktestowac/awesome-copilot-for-testers/test-driven-development-quick.svg" alt="Measured on agentmods" height="20"></a>
Per session 108 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,694 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 5.1 $0.00108 $0.01694
Opus 5 $0.00054 $0.00847
Sonnet 5 $0.00022 $0.00339
Haiku 4.5 $0.00011 $0.00169

Measured 6d ago against content hash b8ce7268a601, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

test-driven-development-quick 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 6d 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/test-driven-development/skills/test-driven-development-quick/SKILL.md · 124 lines

How it starts

The opening of the file, as written. The whole thing — 124 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Quick TDD

A compact standard for the red-green-refactor loop: enough to keep every change verified, short enough to read in one pass.

Framework-agnostic - match whatever runner and assertion style the project already uses. If none exists, ask which runner to target before the first test.

When to Use

  1. Build one new behavior test-first.
  2. Fix a bug by reproducing it with a failing test.
  3. Add a small branch or rule to code that already has tests.

Escalate to test-driven-development when the feature spans several units, needs an outside-in double loop, enters untested legacy code, or runs long enough to need a cycle log. Use writing-unit-tests when the code already exists and tests are being added after the fact.

Before the First Test

State three things:

  • the behavior being built, in the user's vocabulary
  • the seam - the public interface a real caller would use, which the tests observe through; name it and get it confirmed rather than assuming it
  • the test list - the behaviors to build, smallest and most central first, worked one at a time

The list is a queue, not a batch. Writing all the tests up front verifies imagined behavior and locks in a shape nobody has validated.

Match the project's existing runner, test locations, and naming, and find the command that runs a single test file - the loop only works while observing red and green is cheap.

The Loop

Red

  1. Write one failing test for the next list entry.
  2. Run it and read the real output.
  3. Confirm it fails on the missing behavior - not a typo, missing import, or broken fixture. A mechanical failure is not red: fix it and run again.
  4. If it passes immediately, stop. Either the behavior exists already or the test asserts nothing.
  5. Check the expected value came from outside the implementation - the spec, a worked example, a known-good literal. A value recomputed the way the code computes it, or imported from the code's own constants, passes by construction.

Read the full file on GitHub · 124 lines

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. 6d ago First seen · 124 lines · 108 tokens per session scan A b8ce7268a601

Subscribe to this mod's changes

test-driven-development-quick is a skill published in the GitHub repository jaktestowac/awesome-copilot-for-testers (113 stars, last pushed 10d ago), licensed MIT. It adds 108 tokens to every session and 1,694 once invoked, about $0.0005 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.