gh-jordanburke-typescript-library-template-typescript-standards/skills/typescript-standards

TypeScript Standards Skill

Claude Code skill for creating and standardizing TypeScript library projects.

Overview

This skill provides comprehensive guidance for:

• Creating new TypeScript libraries from the typescript-library-template
• Applying standardized tooling and scripts to existing projects
• Configuring modern build tools (tsup, Vitest, ESLint, Prettier)
• Setting up dual module format (CommonJS + ES modules)

Skill Contents

typescript-standards/
├── SKILL.md                        # Main skill guide (loaded by Claude Code)
└── references/
    ├── template-setup.md           # Complete guide for new projects
    ├── standardization.md          # Migration guide for existing projects
    └── tooling-reference.md        # Configuration reference for all tools

When Claude Code Uses This Skill

The skill automatically activates when:

• Creating new TypeScript libraries or npm packages
• Standardizing build scripts across TypeScript projects
• Setting up or migrating to dual module format
• Configuring tsup, Vitest, ESLint, or Prettier
• Publishing packages to npm
• Migrating from webpack, rollup, Jest, or other tools

Installation

For Use in Other Projects

# Copy to Claude Code skills directory
cp -r .claude/skills/typescript-standards ~/.claude/skills/

# Verify installation
ls ~/.claude/skills/typescript-standards

For Marketplace Distribution

This skill is configured for marketplace distribution via .claude-plugin/marketplace.json.

Key Features

1. Template Setup Guide

Complete walkthrough for creating new libraries:

• Clone and customize the template
• Project configuration checklist
• Development workflow
• Publishing to npm
• CI/CD setup

See: references/template-setup.md

2. Standardization Guide

Migrate existing projects to template standards:

• Step-by-step migration process
• Tool-by-tool configuration updates
• Test migration (Jest → Vitest)
• Build migration (webpack/rollup → tsup)
• Common issues and solutions

See: references/standardization.md

3. Tooling Reference

Comprehensive configuration reference:

• tsup - Build configuration with all options
• Vitest - Testing configuration and patterns
• ESLint - Flat config format with TypeScript
• Prettier - Code formatting standards
• TypeScript - Strict mode configuration

See: references/tooling-reference.md

Standardized Commands

The skill teaches this consistent command pattern:

# Main validation
pnpm validate        # Format → Lint → Test → Build

# Individual operations
pnpm format          # Write formatted code
pnpm format:check    # Validate formatting only
pnpm lint            # Fix ESLint issues
pnpm lint:check      # Check linting only
pnpm test            # Run tests
pnpm test:watch      # Watch mode
pnpm test:coverage   # With coverage
pnpm build           # Production build
pnpm dev             # Development watch

Core Principles

1. Consistency - Same commands work across all projects
2. Dual Format - CommonJS + ES modules with TypeScript declarations
3. Type Safety - Strict TypeScript with pragmatic exceptions
4. Modern Tooling - Fast builds (tsup), fast tests (Vitest)
5. Quality Gates - Single validate command ensures everything passes

Example Usage

Creating a New Library

// User: "Create a new TypeScript library for date utilities"
// Claude Code (using this skill):
// 1. Guides through cloning template
// 2. Provides customization checklist
// 3. Explains development workflow
// 4. Assists with implementation
// 5. Validates before publish

Standardizing Existing Project

// User: "Apply typescript-library-template standards to this project"
// Claude Code (using this skill):
// 1. Analyzes current setup
// 2. Proposes migration plan
// 3. Updates dependencies
// 4. Copies configurations
// 5. Migrates tests and build
// 6. Validates everything works

Configuration Templates

The skill provides complete, working configurations for:

tsup.config.ts

Environment-based builds with dual format output

vitest.config.ts

Testing with coverage and multiple reporters

eslint.config.mjs

Flat config with TypeScript, Prettier, and import sorting

package.json

Standardized scripts and dual module exports

tsconfig.json

Strict TypeScript with pragmatic defaults

Validation Checklist

The skill ensures projects meet these standards:

• Dual module format (CJS + ESM + types)
• Standardized scripts (validate, format, lint, etc.)
• Modern build tool (tsup)
• Modern test framework (Vitest)
• Strict TypeScript configuration
• ESLint + Prettier integration
• Pre-publish validation (prepublishOnly)
• Proper package.json exports
• Documentation (CLAUDE.md, README.md)

Advanced Features

Multiple Entry Points

The skill guides setting up subpath exports:

{
  "exports": {
    ".": "./dist/index.js",
    "./utils": "./dist/utils.js"
  }
}

Custom Build Configurations

Adapting tsup for specific needs:

• Browser-compatible builds
• Peer dependency handling
• Custom minification
• Code splitting

Migration Patterns

Common migration scenarios:

• webpack → tsup
• rollup → tsup
• Jest → Vitest
• TSLint → ESLint
• Old ESLint configs → Flat config

Troubleshooting

The skill includes solutions for common issues:

• Module resolution errors
• Test migration problems
• Build configuration issues
• Type generation failures
• Dual format compatibility

Resources

• Template Repository: https://github.com/jordanburke/typescript-library-template
• Example Implementation: See the functype project for advanced usage
• Marketplace Distribution: .claude-plugin/marketplace.json

Contributing

To improve this skill:

1. Edit files in .claude/skills/typescript-standards/
2. Test changes with Claude Code
3. Update documentation as needed
4. Commit changes to the repository

Version History

• 1.0.0 - Initial release
  • Template setup guide
  • Standardization guide
  • Tooling reference
  • Marketplace configuration

License

MIT - Same as the typescript-library-template repository