testing-preferred-patterns

testing-preferred-patterns is a skill for Claude Code from notque/vexjoy-agent. It costs 21 tokens per session (2,166 once invoked), scanned A, original, MIT.

A testing-quality checker for unit, integration, and end-to-end tests. It looks for tests that are unreliable, overly dependent on implementation details, or use too many mocks.

In plain words
What is it for?
Auditing existing test suites and improving flaky, brittle, or over-mocked tests, including gaps around errors, boundaries, concurrency, and security.
Why use it?
It helps prevent tests that fail randomly, break during harmless code changes, or pass without checking real behavior.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter. Also seen: mentions CLAUDE.md.

Good fit Auditing existing test suites and improving flaky, brittle, or over-mocked tests, including gaps around errors, boundaries, concurrency, and security.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/notque/vexjoy-agent/testing-preferred-patterns
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 notque/vexjoy-agent --skill testing-preferred-patterns
Clone the repo
git clone --depth 1 https://github.com/notque/vexjoy-agent

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 testing-preferred-patterns

README.md
[![agentmods](https://agentmods.dev/badge/skills/notque/vexjoy-agent/testing-preferred-patterns/github.svg)](https://agentmods.dev/skills/notque/vexjoy-agent/testing-preferred-patterns)
Your own site
<a href="https://agentmods.dev/skills/notque/vexjoy-agent/testing-preferred-patterns"><img src="https://agentmods.dev/badge/skills/notque/vexjoy-agent/testing-preferred-patterns/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for testing-preferred-patterns

Your own site · 80×15
<a href="https://agentmods.dev/skills/notque/vexjoy-agent/testing-preferred-patterns"><img src="https://agentmods.dev/badge/skills/notque/vexjoy-agent/testing-preferred-patterns.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 21 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,166 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 $0.00021 $0.02166
Opus 5 $0.00010 $0.01083
Sonnet 5 $0.00004 $0.00433
Haiku 4.5 $0.00002 $0.00217

Measured 8d ago against content hash 9c3fe67d477b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

testing-preferred-patterns 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 8d 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/testing/testing-preferred-patterns/SKILL.md · 216 lines

How it starts

The opening of the file, as written. The whole thing — 216 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Testing Pattern Quality Skill

Overview

This skill identifies and fixes common testing mistakes across unit, integration, and E2E test suites. Tests should verify behavior, be reliable, run fast, and fail for the right reasons.

Scope: This skill focuses on improving test quality and reliability. It complements test-driven-development by addressing what goes wrong with tests, complementing how to write them correctly from scratch.

Out of scope: Writing new tests from scratch (use test-driven-development), fixing fundamental architectural issues (use systematic-refactoring), or profiling test performance with external tools.


Reference Loading Table

Signal Load These Files Why
BAD/GOOD code examples for all 10 testing failure modes preferred-pattern-catalog.md Loads detailed guidance from preferred-pattern-catalog.md.
auditing coverage gaps: concurrency, boundaries, security, error recovery blind-spot-taxonomy.md Loads detailed guidance from blind-spot-taxonomy.md.
errors, error handling error-handling.md Loads detailed guidance from error-handling.md.
fixing review feedback fix-strategies.md Loads detailed guidance from fix-strategies.md.
tests load-test-scenarios.md Loads detailed guidance from load-test-scenarios.md.
classifying test-quality failure modes found during SCAN quality-catalog.md Loads detailed guidance from quality-catalog.md.
fast pattern-symptom-fix lookup quick-reference.md Loads detailed guidance from quick-reference.md.

Instructions

Phase 1: SCAN

Goal: Identify quality issues present in the target test code.

Step 1: Locate test files

Use Grep/Glob to find test files in the relevant area. If user pointed to specific files, start there. Common patterns:

  • Go: *_test.go
  • Python: test_*.py or *_test.py
  • JavaScript/TypeScript: *.test.ts, *.spec.ts, *.test.js, *.spec.js

Step 2: Read CLAUDE.md

Read the full file on GitHub · 216 lines

Files

What ships with it

7 files 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. 8d ago First seen · 216 lines · 21 tokens per session scan A 9c3fe67d477b

Subscribe to this mod's changes

testing-preferred-patterns is a skill published in the GitHub repository notque/vexjoy-agent (419 stars, last pushed 2d ago), licensed MIT. It adds 21 tokens to every session and 2,166 once invoked, about $0.0001 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 2026-09-03.

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