What is javascript-testing-patterns?

A testing guide for JavaScript and TypeScript projects using Jest or Vitest and Testing Library. It covers unit, integration, and end-to-end tests, where end-to-end tests check a complete user flow, plus mocks, fixtures, and coverage settings.

Use it to set up a test system, write AAA-structured tests, mock dependencies, create test data, and configure coverage.

It provides a repeatable way to organize tests and replace external dependencies during testing, rather than relying on manual checks.

javascript-testing-patterns — Skill for Claude Code by findscripter

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 findscripter/everything-skills --skill javascript-testing-patterns

Clone the repo

git clone --depth 1 https://github.com/findscripter/everything-skills

Made for: Claude Code.

Or install 02-engineering, the plugin that ships this one along with the rest of its 125 skills.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/findscripter/everything-skills/javascript-testing-patterns/github.svg)](https://agentmods.dev/skills/findscripter/everything-skills/javascript-testing-patterns)

Your own site

<a href="https://agentmods.dev/skills/findscripter/everything-skills/javascript-testing-patterns"><img src="https://agentmods.dev/badge/skills/findscripter/everything-skills/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/findscripter/everything-skills/javascript-testing-patterns"><img src="https://agentmods.dev/badge/skills/findscripter/everything-skills/javascript-testing-patterns.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 105 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 2,343 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.

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.

Model	Per session	Once invoked
Fable 5.1	$0.00105	$0.02343
Opus 5.5	$0.00042	$0.00937
Sonnet 5.5	$0.00021	$0.00469
Haiku 4.5	$0.00011	$0.00234

Measured today against content hash 0b8ec88a255d, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

javascript-testing-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 today.

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.

02-engineering/javascript-testing-patterns/SKILL.md · 218 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

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.

today First seen · 218 lines · 105 tokens per session scan A 0b8ec88a255d

Subscribe to this mod's changes

javascript-testing-patterns is a skill published in the GitHub repository findscripter/everything-skills (11 stars, last pushed today), with no licence file. It adds 105 tokens to every session and 2,343 once invoked, about $0.0004 per session on Opus 5.5. 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 2026-11-12.

E2E testing Testing Unit testing agent-skills ai-agents javascript jest mock testing-library vitest 公众号

javascript-testing-patterns next to 6 skills from other repositories
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javascript-testing-patternsfindscripter/everything-skills	Skill	11	today	none	A	105	Claude Code
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nestjs-testingFilippoDeSilva/skills	Skill	2	4mo ago	none	A	43	Claude Code, Codex
JavaScript Testing PatternsPramodDutta/qaskills	Skill	248	10d ago	MIT	A	36	Claude Code, Codex