javascript-testing-patterns

javascript-testing-patterns is a skill for Claude Code, Codex from yunseo-kim/agent-toolbox. It costs 63 tokens per session (6,337 once invoked), scanned B, original, no licence file.

A guide for testing JavaScript and TypeScript code with Jest, Vitest, and Testing Library. It covers unit tests for individual parts, integration tests for connected parts, and end-to-end tests for complete user flows.

In plain words
What is it for?
Use it to write tests, configure testing projects, create mocks and fixtures, and build TDD or BDD workflows.
Why use it?
It helps developers choose test approaches, set up test infrastructure, and use techniques such as mocks and reusable test data. TDD means writing tests before the code, while BDD describes behavior in terms of expected outcomes.

Skill for Claude CodeCodex

Which agent this was written for is unclear — body not stored (licence); the path alone says nothing. Also seen: installed under .agents/ (shared by several agents).

Good fit Use it to write tests, configure testing projects, create mocks and fixtures, and build TDD or BDD workflows.

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

Made for: Claude Code, Codex.

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 javascript-testing-patterns

README.md
[![agentmods](https://agentmods.dev/badge/skills/yunseo-kim/agent-toolbox/javascript-testing-patterns/github.svg)](https://agentmods.dev/skills/yunseo-kim/agent-toolbox/javascript-testing-patterns)
Your own site
<a href="https://agentmods.dev/skills/yunseo-kim/agent-toolbox/javascript-testing-patterns"><img src="https://agentmods.dev/badge/skills/yunseo-kim/agent-toolbox/javascript-testing-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 javascript-testing-patterns

Your own site · 80×15
<a href="https://agentmods.dev/skills/yunseo-kim/agent-toolbox/javascript-testing-patterns"><img src="https://agentmods.dev/badge/skills/yunseo-kim/agent-toolbox/javascript-testing-patterns.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 63 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 6,337 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. A grade says what 26 rules found in the file — not that it is safe.
Origin unknown 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 $0.00063 $0.06337
Opus 5.5 $0.00025 $0.02535
Sonnet 5.5 $0.00013 $0.01267
Haiku 4.5 $0.00006 $0.00634

Measured 1mo ago against content hash 5fc959e9123e, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade B, and why

javascript-testing-patterns scanned grade B with 1 finding 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 1mo 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.

Sends data to an external URLmediumData exfiltration

A POST to an outside endpoint may be telemetry or may be exfiltration; either way the mod talks to somewhere, and you should know where.

const response = await fetch("https://api.example.com/users", { method: "POST",
.agents/skills/javascript-testing-patterns/SKILL.md · 1,022 lines

The source is not reproduced here

A licence we could not identify

The repository carries a LICENSE file, but it is custom or dual enough that GitHub cannot name it and neither can this catalogue. Unknown terms are not permission, so the body is not copied here. Read the licence at the source and decide for yourself.

Read it on GitHub

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. 1mo ago First seen · 1,022 lines · 63 tokens per session scan B 5fc959e9123e

Subscribe to this mod's changes

javascript-testing-patterns is a skill published in the GitHub repository yunseo-kim/agent-toolbox (1 stars, last pushed yesterday), with no licence file. It adds 63 tokens to every session and 6,337 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it B with 1 finding (sends data to an external url). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

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