software-test-quality

A method for reviewing software tests and choosing between unit, integration, component, and end-to-end tests. TDD, or test-driven development, is a separate approach for building code test-first.

In plain words
What is it for?
Use it to audit assertions, fixtures, mocks, coverage, flakiness, and test-level choices.
Why use it?
It helps identify tests that are unreliable, too fragile, too slow, or poorly matched to the behavior they should protect.

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/nweii/agent-stuff/software-test-quality
Any agent
npx skills add nweii/agent-stuff --skill software-test-quality
Clone the repo
git clone --depth 1 https://github.com/nweii/agent-stuff

Made for: Claude Code, Codex.

Per session 54 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 674 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 $0.00054 $0.00674
Opus 5 $0.00027 $0.00337
Sonnet 5 $0.00011 $0.00135
Haiku 4.5 $0.00005 $0.00067

Measured yesterday against content hash 9422a37b11a0, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

software-test-quality 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 yesterday.

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/software-test-quality/SKILL.md · 61 lines

How it starts

The opening of the file, as written. The whole thing — 61 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Software test quality

Choose the branch that matches the task:

  • Existing tests or suite → Review test quality
  • Proposed behavior or risk → Choose the test level

Use the tdd skill instead when building a feature or fixing a bug test-first.

Review test quality

Review tests through their public seam: the interface where callers observe behavior. A test should fail when that behavior breaks and survive internal refactors that preserve it.

Apply the Desiderata as design lenses, not a checklist:

  • Isolated: results do not depend on execution order or shared mutable state.
  • Composable: tests combine without hidden coupling or cascading setup.
  • Deterministic: unchanged code and inputs produce the same result.
  • Fast: tests are quick enough to run while working.
  • Writable: creation cost is proportionate to the behavior protected.
  • Readable: motivation and expected behavior are clear.
  • Behavioral: the result changes when the behavior changes.
  • Structure-insensitive: internal refactors do not change the result.
  • Automated: tests run without manual intervention.
  • Specific: failures make the likely cause clear.
  • Predictive: passing gives justified confidence in production behavior.
  • Inspiring: the suite increases confidence instead of creating noise, flakes, or avoidance.

Then inspect the failure modes that a structural review can miss:

  • Weak assertions that prove existence instead of behavior.
  • Fixtures that do not represent production inputs.
  • Risky paths that the suite never exercises.
  • Names that disagree with the behavior asserted.
  • Mocks that encode assumptions the real collaborator does not satisfy.
  • Tautological expectations derived through the same logic as the implementation.

When a test's sensitivity is uncertain and a controlled check is cheap, break the protected behavior minimally and confirm that the test fails for the expected reason. Restore the behavior before continuing.

Report every material weakness, the behavior or risk it affects, and any intentional Desiderata tradeoff. The review is complete when every in-scope test has been assessed and each finding identifies concrete evidence.

Read the full file on GitHub · 61 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. yesterday First seen · 61 lines · 54 tokens per session scan A 9422a37b11a0

Subscribe to this mod's changes

software-test-quality is a skill published in the GitHub repository nweii/agent-stuff (8 stars, last pushed 13d ago), licensed MIT. It adds 54 tokens to every session and 674 once invoked, about $0.0003 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.

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