How to migrate from Webpack to Rspack?

Migrating from Webpack to Rspack is a relatively smooth process because Rspack was designed with Webpack compatibility in mind. Here are the main steps and considerations for migration:

Migration Steps

1. Install Rspack:

   bash
   npm install @rspack/core @rspack/cli -D

   Or use package managers like pnpm or yarn

2. Create Rspack Configuration File:

   • Create rspack.config.js or rspack.config.ts
   • Copy existing webpack.config.js configuration
   • Most Webpack configurations can be used directly

3. Adjust Build Scripts:

   json
   {
     "scripts": {
       "build": "rspack build",
       "dev": "rspack serve"
     }
   }

4. Test Build:

   • Run build commands to check for errors
   • Gradually fix incompatible configurations or plugins

Compatibility Notes

Rspack supports most of Webpack's core configurations:

• Entry: Entry configuration is fully compatible
• Output: Output configuration is mostly compatible
• Module: Module rule configuration is compatible
• Plugins: Some commonly used plugins are compatible, such as HtmlWebpackPlugin, MiniCssExtractPlugin, etc.
• Resolve: Resolution configuration is compatible

Considerations

1. Plugin Compatibility:

   • Not all Webpack plugins are compatible with Rspack
   • Check if the plugin supports Rspack, or find alternatives
   • Commonly used plugins like HtmlWebpackPlugin, DefinePlugin, etc. are usually compatible

2. Loader Compatibility:

   • Most Loaders can be used in Rspack
   • Some special Loaders may need adjustment or replacement

3. Configuration Differences:

   • Rspack may have some configuration options not supported by Webpack
   • Some Webpack configurations may have different default values in Rspack

4. Development Server:

   • Rspack uses rspack serve instead of webpack-dev-server
   • Development server configuration is slightly different

5. TypeScript Support:

   • Rspack natively supports TypeScript, no additional configuration needed
   • Can remove ts-loader and related configurations

Migration Recommendations

1. Gradual Migration:

   • Test in development environment first to ensure functionality works
   • Gradually migrate to production environment
   • Keep Webpack configuration as backup

2. Performance Comparison:

   • Compare build speed before and after migration
   • Monitor memory usage
   • Verify consistency of build results

3. Team Training:

   • Train the team on Rspack features
   • Share best practices and common problem solutions

4. CI/CD Adjustment:

   • Update build commands in CI/CD pipeline
   • Adjust build caching strategy

Through these steps, most projects can smoothly migrate from Webpack to Rspack, enjoying faster build speeds and better development experience.