agent-skills/skills/tsdown/references/option-lint.md

Package Validation (publint & attw)

Validate your package configuration and type declarations before publishing.

Overview

tsdown integrates with publint and Are the types wrong? (attw) to catch common packaging issues. Both are optional dependencies.

Installation

# publint only
npm install -D publint

# attw only
npm install -D @arethetypeswrong/core

# both
npm install -D publint @arethetypeswrong/core

publint

Checks that package.json fields (exports, main, module, types) match your actual output files.

Enable

export default defineConfig({
  publint: true,
})

Configuration

export default defineConfig({
  publint: {
    level: 'error', // 'warning' | 'error' | 'suggestion'
  },
})

CLI

tsdown --publint

attw (Are the types wrong?)

Verifies TypeScript declarations are correct across different module resolution strategies (node10, node16, bundler).

Enable

export default defineConfig({
  attw: true,
})

Configuration

export default defineConfig({
  attw: {
    profile: 'node16',   // 'strict' | 'node16' | 'esm-only'
    level: 'error',       // 'warn' | 'error'
    ignoreRules: ['false-cjs', 'cjs-resolves-to-esm'],
  },
})

Profiles

Profile	Description
strict	Requires all resolutions to pass (default)
node16	Ignores node10 resolution failures
esm-only	Ignores node10 and node16-cjs resolution failures

Ignore Rules

Suppress specific problem types with ignoreRules:

Rule	Description
no-resolution	Module could not be resolved
untyped-resolution	Resolution succeeded but has no types
false-cjs	Types indicate CJS but implementation is ESM
false-esm	Types indicate ESM but implementation is CJS
cjs-resolves-to-esm	CJS resolution points to an ESM module
fallback-condition	A fallback/wildcard condition was used
cjs-only-exports-default	CJS module only exports a default
named-exports	Named exports mismatch between types and implementation
false-export-default	Types declare a default export that doesn't exist
missing-export-equals	Types are missing export = for CJS
unexpected-module-syntax	File uses unexpected module syntax
internal-resolution-error	Internal resolution error in type checking

CLI

tsdown --attw

CI Integration

Both tools support CI-aware options:

export default defineConfig({
  publint: 'ci-only',
  attw: {
    enabled: 'ci-only',
    profile: 'node16',
    level: 'error',
  },
})

Both tools require a package.json in your project directory.

Related Options

• CI Environment - CI-aware option details
• Package Exports - Auto-generate exports field