tsdown 0.21.0-beta.5

v0.21.0-beta.5

on Node.js NPM

v0.21.0-beta.5 - Notable Changes

Breaking Changes

Dependency options renamed to deps namespace

The dependency-related options have been moved under a new deps namespace with clearer names:

• external -> deps.neverBundle
• noExternal -> deps.alwaysBundle
• inlineOnly -> deps.onlyAllowBundle
• skipNodeModulesBundle -> deps.skipNodeModulesBundle

Before:

export default defineConfig({
  external: ['vue'],
  noExternal: ['lodash'],
})

After:

export default defineConfig({
  deps: {
    neverBundle: ['vue'],
    alwaysBundle: ['lodash'],
  },
})

The old options still work but are deprecated and will emit warnings.

failOnWarn default changed from 'ci-only' to false

If you relied on the previous behavior where warnings would fail the build in CI environments, you now need to explicitly set failOnWarn: true or failOnWarn: 'ci-only' in your config.

Node.js < 22.18.0 deprecated

tsdown now emits a deprecation warning when running on Node.js versions below 22.18.0. Plan to upgrade your Node.js version accordingly.

New Features

Experimental Node.js SEA executable bundling (exe)

tsdown can now bundle your TypeScript project into a standalone executable using Node.js Single Executable Applications (SEA). A new @tsdown/exe package provides cross-platform executable building support. See the exe documentation for details.

export default defineConfig({
  exe: true, // or { useCodeCache: true, useSnapshot: true }
})

Full CSS pipeline with @tsdown/css

CSS handling has been reimplemented as a native Rolldown plugin and extracted into the @tsdown/css package, providing a complete CSS pipeline with Lightning CSS and PostCSS support via the css.transformer option. See the CSS documentation for details.

inlinedDependencies field in package.json

When using the exports feature, tsdown now auto-generates an inlinedDependencies field in your package.json, listing dependencies that are bundled into the output.

Object option for customExports

customExports now supports an object format for more fine-grained control over the generated exports field.

Migration Guide

1. Update dependency options: Rename external -> deps.neverBundle, noExternal -> deps.alwaysBundle, etc.
2. Check failOnWarn: If you need warnings to fail the build in CI, explicitly set failOnWarn: 'ci-only' or failOnWarn: true.
3. Upgrade Node.js: Ensure you're running Node.js >= 22.18.0 to avoid deprecation warnings.

Links

• tsdown Documentation
• v0.21.0-beta.1 Release
• v0.21.0-beta.2 Release
• v0.21.0-beta.3 Release
• v0.21.0-beta.4 Release
• v0.21.0-beta.5 Release
• Full diff from v0.20.3

   🚨 Breaking Changes

• exe: Require Node >=25.7 and default format to esm  -  by @sxzz in #798 (0173c)

   🚀 Features

• css: Default css.transformer to lightningcss  -  by @sxzz in #797 (288a5)

   🐞 Bug Fixes

• Resolve css files in node_modules  -  by @ocavue, @sxzz and Rei in #795 (d8a1f)

    View changes on GitHub