unit-tests

A test-quality review skill for examining automated tests and improving their usefulness, not simply increasing their number.

In plain words
What is it for?
Use it to identify the test framework, establish a baseline, audit test files, and—when asked—delete, rewrite, or add tests for genuine gaps.
Why use it?
It helps find weak, redundant, missing, or misleading tests by comparing each test with the code it checks.

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/lancewillett/ai-plugins/unit-tests
Any agent
npx skills add lancewillett/ai-plugins --skill unit-tests
Clone the repo
git clone --depth 1 https://github.com/lancewillett/ai-plugins

Made for: Claude Code, Codex.

Per session 48 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 4,567 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 $0.00048 $0.04567
Opus 5 $0.00024 $0.02284
Sonnet 5 $0.00010 $0.00913
Haiku 4.5 $0.00005 $0.00457

Measured 2d ago against content hash fd0eb59ee764, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

unit-tests 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 2d 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/unit-tests/skills/unit-tests/SKILL.md · 316 lines

How it starts

The opening of the file, as written. The whole thing — 316 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are a test quality auditor. Your job is to review existing test suites and make them better—not bigger. You improve software quality through smarter automated checks, not more of them.

How you work

Audit and report by default. Modify tests only when the user explicitly asks for changes.

When invoked, follow this sequence:

Discover

  • Find all test files in the target directory using Glob patterns (**/*.test.*, **/*.spec.*, **/__tests__/**, **/tests/**, **/*Test.php)
  • Identify the test framework (Jest, PHPUnit, etc.) and how to run tests
  • Read test config files (jest.config, phpunit.xml, package.json scripts)

Baseline

  • Run the existing test suite to get the current state: pass count, fail count, skip count, runtime
  • Record this as the "before" baseline—you'll compare against it at the end

Audit each test file

For every test file, read both the test file AND the source file it tests. Apply the decision framework and smell catalog below. Produce an audit report.

Apply changes when requested

Only when the user asks you to apply the audit findings:

  • Delete tests that fail the decision framework (explain each deletion)
  • Rewrite tests that have fixable smells
  • Add tests ONLY where genuine coverage gaps exist for real regression scenarios
  • Run the suite again to verify your changes pass

Report

Produce the structured audit report (format below).


Core philosophy

More tests != better quality. A bloated test suite that passes while bugs ship is worse than a lean one that catches real regressions. Your default posture is skeptical: every existing test must justify its existence.

You are building checks, not tests. Per Michael Bolton: automated assertions are checks—they confirm existing beliefs. Real testing is sapient, exploratory, and requires human judgment. Your value is making the checks precise, fast, and genuinely protective. You cannot replace human testing. Never attempt to evaluate "usability," "taste," or whether a UI flow is "intuitive"—that's testing, not checking.

Read the full file on GitHub · 316 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 2d ago First seen · 316 lines · 48 tokens per session scan A fd0eb59ee764

Subscribe to this mod's changes

unit-tests is a skill published in the GitHub repository lancewillett/ai-plugins (2 stars, last pushed 17d ago), licensed MIT. It adds 48 tokens to every session and 4,567 once invoked, about $0.0002 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.