Skills antfu

Name: antfu
Author: antfu

Anthony Fu's opinionated tooling and conventions for JavaScript/TypeScript projects. Use when setting up new projects, configuring ESLint/Prettier alternatives, monorepos, library publishing, or when the user mentions Anthony Fu's preferences.

install

source · Clone the upstream repo

git clone https://github.com/antfu/skills

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/antfu/skills "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/antfu" ~/.claude/skills/antfu-skills-antfu && rm -rf "$T"

manifest: skills/antfu/SKILL.md

source content

Coding Practices

Code Organization

Single responsibility: Each source file should have a clear, focused scope/purpose
Split large files: Break files when they become large or handle too many concerns
Type separation: Always separate types and interfaces into
```
types.ts
```
or
```
types/*.ts
```
Constants extraction: Move constants to a dedicated
```
constants.ts
```
file

Runtime Environment

Prefer isomorphic code: Write runtime-agnostic code that works in Node, browser, and workers whenever possible
Clear runtime indicators: When code is environment-specific, add a comment at the top of the file:

// @env node
// @env browser

TypeScript

Explicit return types: Declare return types explicitly when possible
Avoid complex inline types: Extract complex types into dedicated
```
type
```
or
```
interface
```
declarations

Comments

Avoid unnecessary comments: Code should be self-explanatory
Explain "why" not "how": Comments should describe the reasoning or intent, not what the code does

Testing (Vitest)

Test files:
```
foo.ts
```
→
```
foo.test.ts
```
(same directory)
Use
```
describe
```
/
```
it
```
API (not
```
test
```
)
Use
```
toMatchSnapshot
```
for complex outputs
Use
```
toMatchFileSnapshot
```
with explicit path for language-specific snapshots

Tooling Choices

@antfu/ni Commands

Command	Description
`ni`	Install dependencies
`ni <pkg>` / `ni -D <pkg>`	Add dependency / dev dependency
`nr <script>`	Run script
`nu`	Upgrade dependencies
`nun <pkg>`	Uninstall dependency
`nci`	Clean install ( `pnpm i --frozen-lockfile` )
`nlx <pkg>`	Execute package ( `npx` )

TypeScript Config

{
  "compilerOptions": {
    "target": "ESNext",
    "module": "ESNext",
    "moduleResolution": "bundler",
    "strict": true,
    "esModuleInterop": true,
    "skipLibCheck": true,
    "resolveJsonModule": true,
    "isolatedModules": true,
    "noEmit": true
  }
}

ESLint Setup

// eslint.config.mjs
import antfu from '@antfu/eslint-config'

export default antfu()

When completing tasks, run

pnpm run lint --fix

to format the code and fix coding style.

For detailed configuration options: antfu-eslint-config

Git Hooks

{
  "simple-git-hooks": {
    "pre-commit": "pnpm i --frozen-lockfile --ignore-scripts --offline && npx lint-staged"
  },
  "lint-staged": { "*": "eslint --fix" },
  "scripts": {
    "prepare": "npx simple-git-hooks"
  }
}

pnpm Catalogs

Use named catalogs in

pnpm-workspace.yaml

for version management:

Catalog	Purpose
`prod`	Production dependencies
`inlined`	Bundler-inlined dependencies
`dev`	Dev tools (linter, bundler, testing)
`frontend`	Frontend libraries

Avoid the default catalog. Catalog names can be adjusted per project needs.

References

Topic	Description	Reference
ESLint Config	Framework support, formatters, rule overrides, VS Code settings	antfu-eslint-config
Project Setup	.gitignore, GitHub Actions, VS Code extensions	setting-up
App Development	Vue/Nuxt/UnoCSS conventions and patterns	app-development
Library Development	tsdown bundling, pure ESM publishing	library-development
Monorepo	pnpm workspaces, centralized alias, Turborepo	monorepo