Test Writing Workflow
iOfficeAI/AionUi
Sets the test-writing workflow for the repository: risk-first scenario lists, behavior-focused Vitest tests, a full run before each commit and a coverage target.
A skill your agent uses when the user asks about Vitest mocking, spies, stubs, fake timers, config, or test runner behavior.
Install Vitest
$ npx skills add confluentinc/mcp-confluent --skill vitest -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install confluentinc/mcp-confluent vitest --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/confluentinc/mcp-confluent.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.claude/skills/vitest .claude/skills/vitest && 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" agent skill from https://github.com/confluentinc/mcp-confluent/tree/main/.claude/skills/vitest into .claude/skills/vitest/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "vitest", 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/confluentinc/mcp-confluent/tree/main/.claude/skills/vitestType 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 confluentinc/mcp-confluent --skill vitest -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install confluentinc/mcp-confluent vitest --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/confluentinc/mcp-confluent.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.claude/skills/vitest .agents/skills/vitest && 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" agent skill from https://github.com/confluentinc/mcp-confluent/tree/main/.claude/skills/vitest into .agents/skills/vitest/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "vitest", 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 confluentinc/mcp-confluent --skill vitest -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install confluentinc/mcp-confluent vitest --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/confluentinc/mcp-confluent.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.claude/skills/vitest .cursor/skills/vitest && 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" agent skill from https://github.com/confluentinc/mcp-confluent/tree/main/.claude/skills/vitest into .cursor/skills/vitest/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "vitest", 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/confluentinc/mcp-confluent.git --path .claude/skills/vitest--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 confluentinc/mcp-confluent --skill vitest -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install confluentinc/mcp-confluent vitest --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/confluentinc/mcp-confluent.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.claude/skills/vitest .gemini/skills/vitest && 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" agent skill from https://github.com/confluentinc/mcp-confluent/tree/main/.claude/skills/vitest into .gemini/skills/vitest/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "vitest", 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 confluentinc/mcp-confluent vitestInstalls 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 confluentinc/mcp-confluent --skill vitest -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/confluentinc/mcp-confluent.git skills-src && mkdir -p .github/skills && cp -r skills-src/.claude/skills/vitest .github/skills/vitest && 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" agent skill from https://github.com/confluentinc/mcp-confluent/tree/main/.claude/skills/vitest into .github/skills/vitest/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "vitest", 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 confluentinc/mcp-confluent --skill vitest -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install confluentinc/mcp-confluent vitest --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/confluentinc/mcp-confluent.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.claude/skills/vitest .opencode/skills/vitest && 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" agent skill from https://github.com/confluentinc/mcp-confluent/tree/main/.claude/skills/vitest into .opencode/skills/vitest/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "vitest", 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- GitHub stars
- 167
- Token cost
- ~1.7k tokens
- SKILL.md length
- 534 words
- Files
- 1
- Skills in repo
- 3
- Repo updated
- First seen
- Licence
- MIT
At a glance
A skill your agent uses when the user asks about Vitest mocking, spies, stubs, fake timers, config, or test runner behavior.
- Works in 5 steps: Determine the question type → Check project rules first - read… → Fetch the relevant page with WebFetch → …
- The user asks about Vitest mocking
- SKILL.md covers Sources, Process, Topic Selection Examples and Output Format, plus 2 more sections
- Calls vitest; reaches vitest.dev
What it does
Vitest is an agent skill from confluentinc/mcp-confluent. Use when the user asks about Vitest mocking, spies, stubs, fake timers, config, or test runner behavior. Triggers on questions like "vi.fn", "vi.spyOn", "vi.mocked", "Mocked<T", "mockResolvedValue", "restoreMocks", "vitest mock", "createMockInstance", "useFakeTimers", or how to accomplish test double patterns with Vitest.
Its SKILL.md is about 1.7k 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. The licence is MIT.
When your agent uses it
- The user asks about Vitest mocking
- Test runner behavior
- Questions like vi.fn
- MockResolvedValue
Example prompts
- “vi.spyOn”
- “vi.mocked”
- “Mocked<T”
- “/vitest”
Requirements
- Pre-approved tools (allowed-tools): Read, Bash, WebFetch, WebSearch
Workflow steps
5 steps, taken from the first numbered list in SKILL.md.
- Determine the question type
- Check project rules first - read .claude/rules/unit-tests.md before fetching. It already
- Fetch the relevant page with WebFetch
- Look at existing project tests for pattern examples before synthesizing your own
- Cross-reference version: this project is on Vitest v4. If a WebSearch result or older
What it can do on your machine
Read from SKILL.md and the folder at commit 76cffd5. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves these tools, so the agent can use them without asking each time:
ReadBashWebFetchWebSearch
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
vitest
From the folder's file list and the shell code blocks in SKILL.md.
Network
Hosts in commands or code, which the agent is likely to contact:
vitest.dev
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 loads about 1.7k tokens when it runs. Until then it costs about 83 tokens; SKILL.md has 534 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: notes
The automated check noted patterns worth knowing about, such as sudo or a known installer.
- NotePre-approves every shell command (allowed-tools: Bash)SKILL.md
allowed-tools: Read, Bash, WebFetch, WebSearch
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 confluentinc/mcp-confluent at commit 76cffd5, republished under its MIT licence (© confluentinc). 534 words, ~1,675 tokens.
Download SKILL.mdSave it as
.claude/skills/vitest/SKILL.md (or your agent's skills folder).- name
- vitest
- description
- Use when the user asks about Vitest mocking, spies, stubs, fake timers, config, or test runner behavior. Triggers on questions like "vi.fn", "vi.spyOn", "vi.mocked", "Mocked<T>", "mockResolvedValue", "restoreMocks", "vitest mock", "createMockInstance", "useFakeTimers", or how to accomplish test double patterns with Vitest.
- allowed-tools
- Read, Bash, WebFetch, WebSearch
Vitest Documentation Lookup
Look up Vitest APIs, patterns, and best practices via WebFetch against the official docs. Use this
skill to answer questions about vi.*, mock instances, assertions, fake timers, and config
options. Project-specific test conventions (naming, stubbing strategy, node-deps.ts pattern) live
in .claude/rules/unit-tests.md - reference that rule rather than re-deriving the conventions.
Sources
Base URL: https://vitest.dev
| Topic | Path | Use for |
|---|---|---|
| Getting started | /guide/ | General concepts, project setup, runner behavior |
| Mocking guide | /guide/mocking | Worked examples: modules, timers, dates, classes |
| Config reference | /config/ | vitest.config.ts options (restoreMocks, pool, coverage) |
vi API | /api/vi | Top-level helpers (vi.fn, vi.spyOn, vi.mocked, timers) |
| Mock instance API | /api/mock | Methods on a Mock (.mockReturnValue, .mockImplementation) |
| Assertions | /api/expect | expect() matchers, argument matchers |
| Fake timers | /api/vi#vi-usefaketimers | vi.useFakeTimers, advanceTimersByTimeAsync |
| CLI | /guide/cli | vitest run, flags, watch mode |
Process
Determine the question type
- API reference (exact signature, options, return type) →
/api/*pages - Pattern guidance / worked examples →
/guide/mockingor/guide/ - Config option behavior →
/config/ - CLI flag / runner behavior →
/guide/cli
- API reference (exact signature, options, return type) →
Check project rules first - read
.claude/rules/unit-tests.mdbefore fetching. It already documents:restoreMocks: truebehavior, thenode-deps.tsnamespace pattern,createMockInstance, constructor-stub gotchas, and thevi.mockanti-pattern. Don't re-explain these; cite the rule and only fetch docs for anything beyond it.Fetch the relevant page with WebFetch:
WebFetch: https://vitest.dev/api/mock Prompt: "Find the signature and options for [specific method, e.g. mockImplementationOnce]"For cross-cutting questions (e.g. "how do I mock a class constructor"), fetch the guide page (
/guide/mocking) alongside the API page.Look at existing project tests for pattern examples before synthesizing your own:
Grep: "vi\.spyOn|createMockInstance|vi\.useFakeTimers" --glob "**/*.test.ts"Good reference files:
src/confluent/telemetry.test.ts(many spies),src/cli.test.ts(env-proxy spying),src/confluent/oauth/token-store.test.ts(async + timers).Cross-reference version: this project is on Vitest v4. If a WebSearch result or older example uses
vi.mockfactories or pre-v1 APIs, verify against the v4/api/*page before recommending.
Show full SKILL.md (258 more words)Show less
Topic Selection Examples
| User asks about… | Fetch |
|---|---|
| "how do I stub a class constructor?" | /guide/mocking + /api/vi |
"what's the difference between vi.fn and vi.spyOn?" | /api/vi |
| "mock returns different value on second call" | /api/mock (mockReturnValueOnce) |
| "how do I advance fake timers in an async test?" | /api/vi#vi-usefaketimers |
"what does restoreMocks do?" | /config/ (search: restoreMocks) |
| "how to type a stubbed class instance?" | unit-tests.md (project helper) + /api/vi (Mocked<T>) |
| "argument matcher for partial object" | /api/expect (expect.objectContaining) |
| "why can't I spy on this ESM import?" | unit-tests.md §Design for Stubbing (no fetch needed) |
Output Format
API Reference
## Vitest: [method/feature]
### Signature
[From /api/*]
### Example
[Adapted to project patterns where relevant]
### Project usage
[Reference to unit-tests.md section or a real `.test.ts` file if applicable]Pattern Guidance
## Pattern: [description]
### From the docs
[Approach recommended by /guide/mocking or /api/*]
### In this project
[How existing tests implement it; cite file paths]
### Gotchas
[Edge cases - e.g. arrow-fn constructor, ESM live bindings, mock hoisting]Anti-patterns (project-specific)
- Don't use
vi.mock: it hoists above imports, loses type safety, and splits the project's stubbing model. If a dependency can't be spied on, wrap it in a namespace object (seesrc/confluent/node-deps.ts). Full rationale in.claude/rules/unit-tests.md§Whyvi.mockis not used in this project. - Don't add
afterEachrestore blocks:restoreMocks: trueinvitest.config.tshandles it. - Don't use arrow functions for constructor mocks: arrows aren't constructable. Use a regular
functionwithvi.spyOn(ns, "Ctor").mockImplementation(function () { return {...}; }).
Tips
- Prefer
/api/*pages for signature lookups,/guide/*for worked examples. /api/vicovers top-level helpers (vi.fn,vi.spyOn, timers, module hooks);/api/mockcovers methods on aMockinstance. Pick the right one based on whether the user is asking "how do I create this mock" vs. "how do I configure an existing mock".- v4 is current. Older blog posts and Stack Overflow answers often show pre-v1 or
vi.mock-heavy patterns - verify against the current API page before recommending. - For anything that overlaps with
.claude/rules/unit-tests.md, cite the rule instead of duplicating its tables in the response.
© confluentinc, 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 .claude/skills/vitest of confluentinc/mcp-confluent.
Open the folder on GitHubat commit 76cffd5
Compare with similar skills
Vitest 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 this skillconfluentinc/mcp-confluent | 167 | — | ~1.7k | Automated safety check: Notes | MIT | |
| Test Writing WorkflowiOfficeAI/AionUi | 33k | 1 repos | ~1.2k | Automated safety check: Pass | Apache-2.0 | |
| Vitestsupabase/supabase | 111k | 12 repos | ~1.1k | Automated safety check: Pass | Apache-2.0 | |
| Test GuardamElnagdy/guard-skills | 1.3k | 2 repos | ~2.1k | Automated safety check: Pass | MIT | |
| Control UI E2Eopenclaw/openclaw | 392k | — | ~2.9k | Automated safety check: Pass | MIT | |
| Adding LLM MCP ToolsTriliumNext/Trilium | 38k | — | ~2.5k | Automated safety check: Pass | AGPL-3.0 |
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Related
Works with
Categories
Questions about Vitest
What does Vitest do?
A skill your agent uses when the user asks about Vitest mocking, spies, stubs, fake timers, config, or test runner behavior. Vitest is an agent skill from confluentinc/mcp-confluent. Use when the user asks about Vitest mocking, spies, stubs, fake timers, config, or test runner behavior.
When should I use Vitest?
Vitest fits situations like: the user asks about Vitest mocking; test runner behavior; questions like vi.fn; mockResolvedValue.
How do I install Vitest in Claude Code?
Run `npx skills add confluentinc/mcp-confluent --skill vitest -a claude-code`. Or copy the skill folder (.claude/skills/vitest in confluentinc/mcp-confluent) into .claude/skills/vitest in your project. Claude Code loads it when a task matches its description.
How do I install Vitest in Codex?
Run `npx skills add confluentinc/mcp-confluent --skill vitest -a codex`. Or copy the skill folder (.claude/skills/vitest in confluentinc/mcp-confluent) into .agents/skills/vitest in your project. Codex loads it when a task matches its description.
Can I use Vitest 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 confluentinc/mcp-confluent --skill vitest -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, .gemini/skills/vitest, .github/skills/vitest and .opencode/skills/vitest in your project.
What does Vitest need to run?
Going by SKILL.md and its folder, Vitest needs the command-line tools its instructions call (vitest). Its frontmatter pre-approves these tools: Read, Bash, WebFetch, WebSearch.
Does Vitest access the network?
SKILL.md names 1 domain. In commands or code: vitest.dev; the agent is likely to contact it when it follows the instructions. This is read from the text; nothing was executed.
Is Vitest safe to install?
Our automated static check of SKILL.md found notes only (pre-approves every shell command (allowed-tools: bash)), nothing it rates as a warning. It is not a guarantee. Review the folder before installing.
What licence does Vitest use?
Vitest is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Vitest use?
About 1.7k tokens (SKILL.md is roughly 6.7k 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?
Skills that share tags, products or a category with Vitest: Test Writing Workflow (iOfficeAI/AionUi, 33k stars), Vitest (supabase/supabase, 111k stars), Test Guard (amElnagdy/guard-skills, 1.3k stars) and Control UI E2E (openclaw/openclaw, 392k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Vitest?
confluentinc (a GitHub organization) maintains it in confluentinc/mcp-confluent, which has 167 GitHub stars. The repository holds 3 skills in this directory. The repository was last updated on October 7, 2026.
Source: confluentinc/mcp-confluent on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.