Vitest
jezweb/claude-skills
Set up Vitest testing in any project — detects type (Cloudflare Workers, React, Node, library), generates vitest.config.ts, test setup, utilities, and a sample test.
Generates Vitest tests in JavaScript/TypeScript with Vite-native speed.
Install Vitest Skill
$ npx skills add sickn33/agentic-awesome-skills --skill vitest-skill -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install sickn33/agentic-awesome-skills vitest-skill --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/sickn33/agentic-awesome-skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/skills/vitest-skill .claude/skills/vitest-skill && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "vitest-skill" agent skill from https://github.com/sickn33/agentic-awesome-skills/tree/main/skills/vitest-skill into .claude/skills/vitest-skill/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "vitest-skill", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/sickn33/agentic-awesome-skills/tree/main/skills/vitest-skillType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add sickn33/agentic-awesome-skills --skill vitest-skill -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install sickn33/agentic-awesome-skills vitest-skill --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/sickn33/agentic-awesome-skills.git skills-src && mkdir -p .agents/skills && cp -r skills-src/skills/vitest-skill .agents/skills/vitest-skill && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "vitest-skill" agent skill from https://github.com/sickn33/agentic-awesome-skills/tree/main/skills/vitest-skill into .agents/skills/vitest-skill/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "vitest-skill", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add sickn33/agentic-awesome-skills --skill vitest-skill -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install sickn33/agentic-awesome-skills vitest-skill --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/sickn33/agentic-awesome-skills.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/skills/vitest-skill .cursor/skills/vitest-skill && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "vitest-skill" agent skill from https://github.com/sickn33/agentic-awesome-skills/tree/main/skills/vitest-skill into .cursor/skills/vitest-skill/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "vitest-skill", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/sickn33/agentic-awesome-skills.git --path skills/vitest-skill--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add sickn33/agentic-awesome-skills --skill vitest-skill -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install sickn33/agentic-awesome-skills vitest-skill --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/sickn33/agentic-awesome-skills.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/skills/vitest-skill .gemini/skills/vitest-skill && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "vitest-skill" agent skill from https://github.com/sickn33/agentic-awesome-skills/tree/main/skills/vitest-skill into .gemini/skills/vitest-skill/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "vitest-skill", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install sickn33/agentic-awesome-skills vitest-skillInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add sickn33/agentic-awesome-skills --skill vitest-skill -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/sickn33/agentic-awesome-skills.git skills-src && mkdir -p .github/skills && cp -r skills-src/skills/vitest-skill .github/skills/vitest-skill && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "vitest-skill" agent skill from https://github.com/sickn33/agentic-awesome-skills/tree/main/skills/vitest-skill into .github/skills/vitest-skill/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "vitest-skill", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add sickn33/agentic-awesome-skills --skill vitest-skill -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install sickn33/agentic-awesome-skills vitest-skill --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/sickn33/agentic-awesome-skills.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/skills/vitest-skill .opencode/skills/vitest-skill && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "vitest-skill" agent skill from https://github.com/sickn33/agentic-awesome-skills/tree/main/skills/vitest-skill into .opencode/skills/vitest-skill/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "vitest-skill", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
vitest-skill- GitHub stars
- 47k
- Used in
- 1 other repo
- Token cost
- ~1.2k tokens
- SKILL.md length
- 235 words
- Files
- 1
- Skills in repo
- 1,354
- Repo updated
- First seen
- Licence
- MIT
At a glance
Generates Vitest tests in JavaScript/TypeScript with Vite-native speed.
- User mentions Vitest
- SKILL.md covers When to Use, Core Patterns, Quick Reference and vitest.config.ts, plus 2 more sections
- Calls npx
- Tasks that involve Unit testing
What it does
Vitest Skill is an agent skill from sickn33/agentic-awesome-skills. Generates Vitest tests in JavaScript/TypeScript with Vite-native speed. Jest-compatible API with ESM support and HMR. Use when user mentions "Vitest", "vi.mock", "vitest.config". Triggers on: "Vitest", "vi.mock", "vi.fn", "Vite test", "vitest config".
Its SKILL.md is about 1.2k tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Testing & QA, covering Unit testing. It works with Vitest, Jest, Vite and TypeScript. The repository describes itself as: AAS Core is the local, agent-first control plane for complete catalog discovery, agent-owned selection, stack validation, and planning, backed by 2,400+ agentic skills. Includes… The licence is MIT.
When your agent uses it
- User mentions Vitest
- Tasks that involve Unit testing
Example prompts
- “Vitest”
- “vi.mock”
- “vitest.config”
- “/vitest-skill”
Requirements
- Node.js
What it can do on your machine
Read from SKILL.md and the folder at commit ec02547. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
npx
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md. Its commands use npx, which can reach the network depending on how they are called.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Vitest Skill loads about 1.2k tokens when it runs. Until then it costs about 66 tokens; SKILL.md has 235 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from sickn33/agentic-awesome-skills at commit ec02547, republished under its MIT licence (© sickn33). 235 words, ~1,202 tokens.
Download SKILL.mdSave it as
.claude/skills/vitest-skill/SKILL.md (or your agent's skills folder).- name
- vitest-skill
- description
- Generates Vitest tests in JavaScript/TypeScript with Vite-native speed. Jest-compatible API with ESM support and HMR. Use when user mentions "Vitest", "vi.mock", "vitest.config". Triggers on: "Vitest", "vi.mock", "vi.fn", "Vite test", "vitest config".
- risk
- critical
- source
- https://github.com/LambdaTest/agent-skills/tree/main/vitest-skill
- source_repo
- LambdaTest/agent-skills
- source_type
- community
- date_added
- 2026-07-01
- license
- MIT
- license_source
- https://github.com/LambdaTest/agent-skills/blob/main/LICENSE
Vitest Testing Skill
When to Use
Use this skill when you need generates Vitest tests in JavaScript/TypeScript with Vite-native speed. Jest-compatible API with ESM support and HMR. Use when user mentions "Vitest", "vi.mock", "vitest.config". Triggers on: "Vitest", "vi.mock", "vi.fn", "Vite test", "vitest config".
Core Patterns
Basic Test
import { describe, it, expect, vi, beforeEach } from 'vitest';
import { Calculator } from './calculator';
describe('Calculator', () => {
let calc: Calculator;
beforeEach(() => { calc = new Calculator(); });
it('adds two numbers', () => {
expect(calc.add(2, 3)).toBe(5);
});
it('throws on divide by zero', () => {
expect(() => calc.divide(10, 0)).toThrow();
});
});Mocking (vi instead of jest)
import { vi } from 'vitest';
// Mock module
vi.mock('./database', () => ({
getUser: vi.fn().mockResolvedValue({ name: 'Alice' }),
saveUser: vi.fn().mockResolvedValue(true),
}));
// Mock function
const mockFn = vi.fn();
mockFn.mockReturnValue(42);
mockFn.mockResolvedValue({ data: 'test' });
// Spy
const spy = vi.spyOn(console, 'log').mockImplementation(() => {});
expect(spy).toHaveBeenCalledWith('message');
spy.mockRestore();
// Timers
vi.useFakeTimers();
vi.advanceTimersByTime(1000);
vi.runAllTimers();
vi.useRealTimers();In-Source Testing
// src/math.ts — tests alongside code!
export function add(a: number, b: number) { return a + b; }
export function multiply(a: number, b: number) { return a * b; }
if (import.meta.vitest) {
const { it, expect } = import.meta.vitest;
it('adds', () => { expect(add(2, 3)).toBe(5); });
it('multiplies', () => { expect(multiply(3, 4)).toBe(12); });
}Snapshot Testing
it('serializes user', () => {
expect(serializeUser(user)).toMatchSnapshot();
});
it('inline snapshot', () => {
expect(serializeUser(user)).toMatchInlineSnapshot(`
{ "name": "Alice", "email": "alice@test.com" }
`);
});React Component Testing
import { render, screen } from '@testing-library/react';
import { describe, it, expect } from 'vitest';
import Button from './Button';
describe('Button', () => {
it('renders with label', () => {
render(<Button label="Click me" />);
expect(screen.getByText('Click me')).toBeDefined();
});
});Anti-Patterns
| Bad | Good | Why |
|---|---|---|
jest.fn() | vi.fn() | Vitest uses vi |
jest.mock() | vi.mock() | Different namespace |
| No type safety | TypeScript + strict | Vitest is TS-first |
Quick Reference
| Task | Command |
|---|---|
| Run once | npx vitest run |
| Watch | npx vitest (default) |
| UI | npx vitest --ui |
| Coverage | npx vitest --coverage |
| Specific file | npx vitest run src/math.test.ts |
| Filter | npx vitest run -t "adds" |
vitest.config.ts
import { defineConfig } from 'vitest/config';
export default defineConfig({
test: {
globals: true,
environment: 'jsdom',
coverage: { provider: 'v8', reporter: ['text', 'html'] },
include: ['src/**/*.{test,spec}.{js,ts,tsx}'],
includeSource: ['src/**/*.{js,ts}'],
},
});Deep Patterns → reference/playbook.md
| § | Section | Lines |
|---|---|---|
| 1 | Production Configuration | Config, workspace, setup file |
| 2 | Mocking Patterns | vi.mock, spies, timers, fetch |
| 3 | React Testing Library | Components, hooks, providers |
| 4 | Snapshot & Inline Snapshots | File, inline, serializers |
| 5 | Table-Driven Tests | test.each, describe.each |
| 6 | In-Source Testing | Co-located tests in source |
| 7 | API / Integration Testing | Server tests with fetch |
| 8 | CI/CD Integration | GitHub Actions, scripts |
| 9 | Debugging Quick-Reference | 10 common problems |
| 10 | Best Practices Checklist | 13 items |
Limitations
- Use this skill only when the task clearly matches its upstream source and local project context.
- Verify commands, generated code, dependencies, credentials, and external service behavior before applying changes.
- Do not treat examples as a substitute for environment-specific tests, security review, or user approval for destructive or costly actions.
© sickn33, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
Just SKILL.md in skills/vitest-skill of sickn33/agentic-awesome-skills.
Open the folder on GitHubat commit ec02547
Used in 1 other repository
We found 5 copies of this SKILL.md (exact, near-identical or edited) in other folders, from 1 other GitHub owner. This page covers the copy in sickn33/agentic-awesome-skills, which our catalogue first saw on October 7, 2026.
Compare with similar skills
Vitest Skill next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Vitest Skill this skillsickn33/agentic-awesome-skills | 47k | 1 repos | ~1.2k | Automated safety check: Pass | MIT | |
| Vitestjezweb/claude-skills | 1.1k | — | ~3k | Automated safety check: Pass | MIT | |
| Vitest Testingsecondsky/claude-skills | 227 | — | ~1.2k | Automated safety check: Notes | MIT | |
| Vitestsupabase/supabase | 111k | 12 repos | ~1.1k | Automated safety check: Pass | Apache-2.0 | |
| Test Coveragescott-fryxell/brayness | 124 | — | ~1.6k | Automated safety check: Pass | MIT | |
| Vitest Migrationnrwl/nx | 29k | — | ~7.3k | Automated safety check: Pass | MIT |
Similar skills
Vitest Testing
secondsky/claude-skills
Modern TypeScript/JavaScript testing with Vitest. An agent skill from secondsky/claude-skills.
- Official
Vitest
supabase/supabase
Vitest API and config reference (Jest-compatible) — mocking with vi., spies, fake timers, coverage configuration, fixtures, snapshots, and test filtering.
Test Coverage
scott-fryxell/brayness
Write Vitest specs for Vue 3 JavaScript (Vite Plus, happy-dom, @vue/test-utils) and analyze V8 coverage + Fallow health to prioritize test-first refactors.
Vitest Migration
nrwl/nx
Migrate an Nx repo package's unit tests from Jest to Vitest, reusing the shared setup that packages/workspace established.
Testing Fundamentals
DanielPodolsky/ownyourcode
Guides test strategy for unit, integration, and E2E testing.
More from sickn33/agentic-awesome-skills
All 1,354 skills in this repoLiuguang Banlan UI
sickn33/agentic-awesome-skills
Implements an interface in one of two named color modes, iridescent white or colorful black, from a parameterized starter that reports measured color intensity.
User Thoughts Memory
sickn33/agentic-awesome-skills
Saves a user's project decisions, rules and preferences into a project-local mdbase so later sessions and other agents can recover the intent.
Using LWC Memory and Graphs
sickn33/agentic-awesome-skills
Keeps project decisions, research and verified results available across coding-agent sessions through LWC memory, a document Wiki graph and a CodeGraph code index.
Find Complementary Founders
sickn33/agentic-awesome-skills
Guides an agent through assessing its own owner for cofounder fit, publishing an approved profile, and ranking complementary profiles other agents published for their owners.
Cline Pilot
sickn33/agentic-awesome-skills
Acts as a proxy for the Cline CLI, dispatching coding tasks one at a time, monitoring runs by hard evidence, relaying decisions to you and learning per-project preferences.
Content Creator
sickn33/agentic-awesome-skills
Drafts and reviews audience-specific content from supplied brand examples, with local scripts for brand voice and SEO diagnostics, channel templates and a content calendar.
Related
Works with
Categories
Questions about Vitest Skill
What does Vitest Skill do?
Generates Vitest tests in JavaScript/TypeScript with Vite-native speed. Vitest Skill is an agent skill from sickn33/agentic-awesome-skills. Generates Vitest tests in JavaScript/TypeScript with Vite-native speed.
When should I use Vitest Skill?
Vitest Skill fits situations like: user mentions Vitest; tasks that involve Unit testing.
How do I install Vitest Skill in Claude Code?
Run `npx skills add sickn33/agentic-awesome-skills --skill vitest-skill -a claude-code`. Or copy the skill folder (skills/vitest-skill in sickn33/agentic-awesome-skills) into .claude/skills/vitest-skill in your project. Claude Code loads it when a task matches its description.
How do I install Vitest Skill in Codex?
Run `npx skills add sickn33/agentic-awesome-skills --skill vitest-skill -a codex`. Or copy the skill folder (skills/vitest-skill in sickn33/agentic-awesome-skills) into .agents/skills/vitest-skill in your project. Codex loads it when a task matches its description.
Can I use Vitest Skill in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add sickn33/agentic-awesome-skills --skill vitest-skill -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/vitest-skill, .gemini/skills/vitest-skill, .github/skills/vitest-skill and .opencode/skills/vitest-skill in your project.
What does Vitest Skill need to run?
Going by SKILL.md and its folder, Vitest Skill needs the command-line tools its instructions call (npx). Our summary lists: Node.js.
Does Vitest Skill access the network?
SKILL.md contains no URLs. Its commands use npx, which can reach the network depending on how they are called. This is read from the text; nothing was executed.
Is Vitest Skill safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Vitest Skill use?
Vitest Skill is published under the MIT licence (declared in SKILL.md). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Vitest Skill use?
About 1.2k tokens (SKILL.md is roughly 4.8k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Vitest Skill?
Skills that share tags, products or a category with Vitest Skill: Vitest (jezweb/claude-skills, 1.1k stars), Vitest Testing (secondsky/claude-skills, 227 stars), Vitest (supabase/supabase, 111k stars) and Test Coverage (scott-fryxell/brayness, 124 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Vitest Skill?
sickn33 (a GitHub user) maintains it in sickn33/agentic-awesome-skills, which has 47,343 GitHub stars. The repository holds 1,354 skills in this directory. The repository was last updated on October 7, 2026.
Source: sickn33/agentic-awesome-skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.