v5.0.0-rc.0

Breaking changes

• Updated to Rspack 2.0. If you customize Rspack, see the Rspack v1 -> v2 migration guide.
• Jetpack is now ESM-only. Use import, require('jetpack/...') is no longer supported.
• Use ESM config in "type": "module" projects: export default { ... }. Use jetpack.config.cjs for CommonJS config.
• Public API exports were trimmed:
  • jetpack now exports only defineConfig and resolveConfig
  • jetpack/serve now exports a serve(config) factory
  • jetpack/rspack.config moved to jetpack/rspack-config
  • jetpack/options and jetpack/proxy were removed; the proxy config option still works
• Build targets changed. Use --target modern|legacy|all and target: 'modern' | 'legacy' | 'all' instead of --modern, --legacy, or target: { modern, legacy }.
• The modern browser target changed from Browserslist defaults to baseline widely available with downstream.
• Dropped the implicit ./src/index.js entry fallback.
• Removed -x / --exec and the exec config option.
• Renamed, moved, or removed several config options:
  • publicPath -> assetBaseUrl
  • dist -> build.outDir
  • build options -> build.outDir, build.sourceMaps, build.minify, and build.chunkLoadRetry
  • HTML options -> html.title, html.cspNonce, and html.render
  • polyfills is now top-level: polyfills: 'usage' | 'entry' | false
  • removed static, config-file dir, and css.features
• For advanced customization, use the rspack config hook. The old webpack hook alias was removed, rspack(config, options) is now rspack(config, context)
• sass-loader resources should use additionalData.

Fixes

• Fixed --no-hot and --no-minify.
• Unknown commands now fail instead of being treated as entry paths.
• Extra positional CLI arguments now fail instead of being ignored.
• resolveConfig({ overrides }) now honors the full public config shape, including nested build, html, css, and assets overrides.
• Asset filenames now use [contenthash:8] for better cache busting.
• jetpack inspect now writes a self-contained dist/inspect.html treemap and opens it automatically in interactive runs.

Improvements

• Runtime asset URLs now work better for CDN deployments and sub-path mounts.
• Added command-specific help, dev --host, clean --yes, and clean --dry-run.
• Added --log=all and --log=silent presets.
• Added a define option for build-time constants backed by rspack.DefinePlugin.
• Added context.findLoader(name) to the rspack config hook for customizing generated loaders by string or RegExp.
• Added assets.inlineLimit to control which image assets are inlined as data URLs. Fonts and media are now emitted as files.
• Added transpileDependencies to control dependency JS transpilation: use true, false, a package list, or { include, exclude }.
• Expanded asset extension list: avif, webp, bmp, ico, aac, flac, m4a, mp3, opus, wav, m4v.
• Replaced webpack dev middleware/HMR with Rspack dev-server and added Jetpack's development error overlay.
• Smaller install: dropped seven runtime dependencies in favour of Node built-ins.