sumo-qa-implementing-with-tdd

sumo-qa-implementing-with-tdd is a skill for Claude Code from sumithr/sumo-qa. It costs 103 tokens per session (4,207 once invoked), scanned A, original, Apache-2.0.

A workflow for test-driven development, or TDD, where a failing test is written before the production code that makes it pass.

In plain words
What is it for?
Use it to write regression tests for bugs, scaffold tests first, make them fail, implement the fix, and review the result.
Why use it?
It proves that the test can detect the problem before implementation begins and guides the change through the failing and passing stages.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the sumo-qa plugin — 20 skills, 2 agents, 3 hooks, 1 MCP server shipped together

Good fit Use it to write regression tests for bugs, scaffold tests first, make them fail, implement the fix, and review the result.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/sumithr/sumo-qa/sumo-qa-implementing-with-tdd
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 sumithr/sumo-qa --skill sumo-qa-implementing-with-tdd
Clone the repo
git clone --depth 1 https://github.com/sumithr/sumo-qa

Made for: Claude Code.

Or install sumo-qa, the plugin that ships this one along with the rest of its 20 skills, 2 agents, 3 hooks, 1 MCP server.

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 sumo-qa-implementing-with-tdd

README.md
[![agentmods](https://agentmods.dev/badge/skills/sumithr/sumo-qa/sumo-qa-implementing-with-tdd.svg)](https://agentmods.dev/skills/sumithr/sumo-qa/sumo-qa-implementing-with-tdd)
Your own site
<a href="https://agentmods.dev/skills/sumithr/sumo-qa/sumo-qa-implementing-with-tdd"><img src="https://agentmods.dev/badge/skills/sumithr/sumo-qa/sumo-qa-implementing-with-tdd.svg" alt="Measured on agentmods" height="20"></a>
Per session 103 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,207 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 warn 7 Sept 2026
SkillSpector: 3 findings, up to high

These are SkillSpector’s own severities. On a checked sample its high-severity flags on skills were ~96% false positives — a documented command, a public API, a “never do X” rule — so we show them as a caution to read, not a verdict. Why →

  • high Tool Misuse · line 72
    Tool parameters are crafted to achieve unintended or unsafe behavior. Parameter abuse can bypass intended safety checks (e.g. shell=True, --force, dangerous glob patterns).
    Fix: Validate all tool parameters against an allowlist. Reject dangerous parameter values (shell=True, --force, -rf /) and use safe defaults.
  • medium Excessive Agency · line 49
    Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.
    Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
  • medium Excessive Agency · line 53
    Skill enables autonomous high-impact decisions without human-in-the-loop verification. Critical operations (destructive commands, financial transactions, data deletion) should require explicit user confirmation.
    Fix: Add human-in-the-loop confirmation for destructive, irreversible, or high-impact operations. Never auto-execute commands that modify files, send data, or alter system state.
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 $0.00103 $0.04207
Opus 5 $0.00051 $0.02103
Sonnet 5 $0.00021 $0.00841
Haiku 4.5 $0.00010 $0.00421

Measured 7d ago against content hash fb482ea71aea, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

sumo-qa-implementing-with-tdd 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 7d 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.

skills/sumo-qa-implementing-with-tdd/SKILL.md · 148 lines

How it starts

The opening of the file, as written. The whole thing — 148 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Implementing with TDD

Drive a change through TDD discipline: walk the cycle one step at a time, confirm the test idea before writing it, prove the red phase before handing back the green-making step. The user has product context (what "wrong" looks like, the API shape) the AI can't infer from code — surface it through questions, don't assume.

Announce at start: "Walking the red→green cycle."

Output discipline (mandatory)

Inherits the global discipline from using-sumo-qa: output discipline (never surface internal taxonomy labels — say "behaviour change in pricing", not "Classification: business_logic_change"), output economy (spend output on findings not framing; no preamble or self-narration; one question per turn; no closing pleasantries), knowledge authority hierarchy, internal scaffolding stays internal, and specialty-tool fit.

The Iron Law

RED PHASE FIRST. NO PRODUCTION CODE BEFORE A FAILING TEST. A test that has never failed has never tested anything — the red phase is the proof.

Stub allowance — narrow. A production-side stub is permitted in the red phase ONLY when the test can't otherwise be collected (e.g. the function under test doesn't exist yet, so the test file fails at import). It must be signature-only: def apply_discounts(order): raise NotImplementedError or : pass. Any behaviour in the stub — a partial implementation, a heuristic return, a branch that happens to satisfy the assertion — is an Iron Law violation: the red phase would then prove the stub matches the assertion, not that the test catches the bug. Writing if/else or computing a value in the stub → stop; that's green-phase work for the user.

When to Use

sumo-qa-deciding-approach routes here for: tdd-scaffold (greenfield-ish new behaviour), regression-first (bug fix — reproduce as a failing test first), or coverage-first-then-refactor (behaviour-preserving refactor — characterization tests pin behaviour BEFORE the refactor).

Read the full file on GitHub · 148 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. 7d ago First seen · 148 lines · 103 tokens per session scan A fb482ea71aea

Subscribe to this mod's changes

sumo-qa-implementing-with-tdd is a skill published in the GitHub repository sumithr/sumo-qa (6 stars, last pushed 3d ago), licensed Apache-2.0. It adds 103 tokens to every session and 4,207 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 2026-08-31.

Related

Other skills, from other repositories

orchestrated-execution

Execute work units through the rigorous 4-phase Metaswarm cycle (Implement -> Validate -> Adversarial Review -> Commit) with independent quality gate enforcement.

a5c-ai/babysitter · 37 tokens

software-test-review

Evaluate the quality of TDD tests against slice acceptance criteria, codebase conventions, and Red-phase execution results, producing a structured review with Accept or Revise recommendations. Use when tests written during the Red phase of red-green-refactor need quality review — checking coverage of acceptance…

stencila/stencila · 127 tokens

software-code-refactoring

Improve production code quality while preserving all existing test behavior. Commonly used for the Refactor phase of TDD red-green-refactor, but applicable to any codebase with tests. Use when production code works but needs cleanup — reducing duplication, improving naming, simplifying complexity, aligning with…

stencila/stencila · 102 tokens

quality-playbook

Run a complete quality engineering audit on any codebase. Derives behavioral requirements from the code, generates spec-traced functional tests, runs a three-pass code review with regression tests, executes a multi-model spec audit (Council of Three), and produces a consolidated bug report with TDD-verified patches.…

andrewstellman/quality-playbook · 111 tokens

superpowers-zh

Use when constraining AI coding with Chinese TDD methodology, systematic debugging, code review, and verification workflows. Superpowers-zh: Chinese adaptation of the Superpowers AI-assisted programming skills and methodologies.

znlgis/opengis-skills · 45 tokens

Pair Programming

AI-assisted pair programming with multiple modes (driver$navigator$switch), real-time verification, quality monitoring, and comprehensive testing. Supports TDD, debugging, refactoring, and learning sessions. Features automatic role switching, continuous code review, security scanning, and performance optimization with…

ruvnet/ruflo · 61 tokens