rspack

CHANGELOG.md

@@ -8,15 +8,15 @@
 ## [Unreleased]
 Changes since the last non-beta release.
 
-
 ### Added
 
-- Support for subresource integrity. [PR 570](https://github.com/shakacode/shakapacker/pull/570) by [panagiotisplytas](https://github.com/panagiotisplytas)
+* Rspack support as an alternative bundler to webpack. Configure `bundler: 'rspack'` in `shakapacker.yml` to use Rspack's faster Rust-based bundling with webpack-compatible API, built-in SWC loader, and CSS extraction. Automatic bundler detection in `bin/shakapacker` with fallback support for webpack configurations.
+* Support for subresource integrity. [PR 570](https://github.com/shakacode/shakapacker/pull/570) by [panagiotisplytas](https://github.com/panagiotisplytas)
 
 ### Fixed
 
-- Install the latest major version of peer dependencies [PR 576](https://github.com/shakacode/shakapacker/pull/576) by [G-Rath](https://github.com/g-rath).
-- Remove duplicate word in comment from generated `shakapacker.yml` config [PR 572](https://github.com/shakacode/shakapacker/pull/572) by [G-Rath](https://github.com/g-rath).
+* Install the latest major version of peer dependencies [PR 576](https://github.com/shakacode/shakapacker/pull/576) by [G-Rath](https://github.com/g-rath).
+* Remove duplicate word in comment from generated `shakapacker.yml` config [PR 572](https://github.com/shakacode/shakapacker/pull/572) by [G-Rath](https://github.com/g-rath).
 
 ## [v8.3.0] - April 25, 2025
 ### Added

docs/rspack.md

@@ -0,0 +1,190 @@
+# Rspack Integration
+
+Shakapacker supports [Rspack](https://rspack.rs) as an alternative bundler to Webpack. Rspack is a fast Rust-based web bundler with webpack-compatible API that can significantly speed up your build times.
+
+## Installation
+
+First, install the required Rspack dependencies:
+
+```bash
+npm install @rspack/core @rspack/cli -D
+# or
+yarn add @rspack/core @rspack/cli -D
+# or  
+pnpm add @rspack/core @rspack/cli -D
+# or
+bun add @rspack/core @rspack/cli -D
+```
+
+Note: These packages are already listed as optional peer dependencies in Shakapacker, so you may see warnings if they're not installed.
+
+## Configuration
+
+To enable Rspack, update your `config/shakapacker.yml`:
+
+```yaml
+default: &default
+  # ... other config options
+  bundler: 'rspack'  # Change from 'webpack' to 'rspack'
+```
+
+## Configuration
+
+Rspack uses its own configuration directory to keep things organized. Create your Rspack configuration file at `config/rspack/rspack.config.js`:
+
+```javascript
+const { generateRspackConfig } = require('shakapacker/rspack')
+
+module.exports = generateRspackConfig()
+```
+
+### Custom Configuration
+
+If you need to customize your Rspack configuration:
+
+```javascript
+const { generateRspackConfig } = require('shakapacker/rspack')
+
+const rspackConfig = generateRspackConfig({
+  plugins: [
+    new SomeRspackCompatiblePlugin()
+  ],
+  resolve: {
+    extensions: ['.ts', '.tsx', '.js', '.jsx']
+  }
+})
+
+module.exports = rspackConfig
+```
+
+### Migration from Webpack Config
+
+If you have an existing `config/webpack/webpack.config.js`, you can migrate it to `config/rspack/rspack.config.js`:
+
+**Old (webpack.config.js):**
+```javascript
+const { generateWebpackConfig } = require('shakapacker')
+module.exports = generateWebpackConfig()
+```
+
+**New (rspack.config.js):**
+```javascript
+const { generateRspackConfig } = require('shakapacker/rspack')
+module.exports = generateRspackConfig()
+```
+
+> **Note:** Shakapacker will show a deprecation warning if you use `config/webpack/webpack.config.js` with `bundler: 'rspack'`. Please migrate to `config/rspack/rspack.config.js`.
+
+## Key Differences from Webpack
+
+### Built-in Loaders
+
+Rspack has built-in loaders that are faster than their webpack counterparts:
+
+- **JavaScript/TypeScript**: Uses `builtin:swc-loader` instead of `babel-loader`
+- **CSS Extraction**: Uses `rspack.CssExtractRspackPlugin` instead of `mini-css-extract-plugin`
+- **Asset Handling**: Uses built-in asset modules instead of `file-loader`/`url-loader`
+
+### Plugin Compatibility
+
+Most webpack plugins work with Rspack, but some have Rspack-specific alternatives:
+
+| Webpack Plugin | Rspack Alternative | Status |
+|---|---|---|
+| `mini-css-extract-plugin` | `rspack.CssExtractRspackPlugin` | Built-in |
+| `copy-webpack-plugin` | `rspack.CopyRspackPlugin` | Built-in |
+| `terser-webpack-plugin` | `rspack.SwcJsMinimizerRspackPlugin` | Built-in |
+
+### Minification
+
+Rspack uses SWC for minification by default, which is significantly faster than Terser:
+
+```javascript
+optimization: {
+  minimize: true,
+  minimizer: [
+    new rspack.SwcJsMinimizerRspackPlugin(),
+    new rspack.SwcCssMinimizerRspackPlugin()
+  ]
+}
+```
+
+## Limitations
+
+- **CoffeeScript**: Not supported with Rspack
+- **Some Webpack Plugins**: May not be compatible; check Rspack documentation
+
+## Commands
+
+All existing Shakapacker commands work the same way and automatically use Rspack when configured:
+
+```bash
+# Build (automatically uses rspack when bundler: 'rspack')
+./bin/shakapacker
+
+# Development server (automatically uses rspack when bundler: 'rspack')  
+./bin/shakapacker-dev-server
+
+# Watch mode
+./bin/shakapacker --watch
+```
+
+The same dev server configuration in `shakapacker.yml` applies to both webpack and rspack.
+
+## Performance Benefits
+
+Rspack typically provides:
+
+- **2-10x faster** cold builds
+- **5-20x faster** incremental builds  
+- **Faster HMR** (Hot Module Replacement)
+- **Lower memory usage**
+
+## Migration Checklist
+
+1. **Install Rspack dependencies:**
+   ```bash
+   npm install @rspack/core @rspack/cli -D
+   ```
+
+2. **Update configuration:**
+   ```yaml
+   # config/shakapacker.yml
+   default: &default
+     bundler: 'rspack'
+   ```
+
+3. **Create Rspack config:**
+   ```javascript
+   // config/rspack/rspack.config.js
+   const { generateRspackConfig } = require('shakapacker/rspack')
+   module.exports = generateRspackConfig()
+   ```
+
+4. **Remove CoffeeScript files** (if any) - not supported by Rspack
+
+5. **Test your application** - same commands work automatically
+
+## Troubleshooting
+
+### Configuration Issues
+
+If you encounter configuration issues:
+
+1. Check that all plugins are Rspack-compatible
+2. Verify custom loaders work with Rspack
+3. Review the [Rspack migration guide](https://rspack.rs/guide/migration/webpack)
+
+### Performance Issues
+
+If builds are unexpectedly slow:
+
+1. Ensure you're using built-in Rspack loaders
+2. Check for webpack-specific plugins that should be replaced
+3. Review your asset optimization settings
+
+## Further Reading
+
+- [Rspack Official Documentation](https://rspack.rs)
+- [Rspack Migration Guide](https://rspack.rs/guide/migration/webpack)
+- [Rspack Plugins](https://rspack.rs/plugins/webpack/)

lib/install/bin/shakapacker

@@ -4,10 +4,22 @@ ENV["RAILS_ENV"] ||= "development"
 ENV["BUNDLE_GEMFILE"] ||= File.expand_path("../../Gemfile", __FILE__)
 
 require "bundler/setup"
+require "pathname"
 require "shakapacker"
-require "shakapacker/webpack_runner"
 
 APP_ROOT = File.expand_path("..", __dir__)
 Dir.chdir(APP_ROOT) do
-  Shakapacker::WebpackRunner.run(ARGV)
+  config = Shakapacker::Configuration.new(
+    root_path: Pathname.new(APP_ROOT),
+    config_path: Pathname.new(File.join(APP_ROOT, "config/shakapacker.yml")),
+    env: ENV["RAILS_ENV"] || ENV["NODE_ENV"] || "development"
+  )
+
+  if config.rspack?
+    require "shakapacker/rspack_runner"
+    Shakapacker::RspackRunner.run(ARGV)
+  else
+    require "shakapacker/webpack_runner"
+    Shakapacker::WebpackRunner.run(ARGV)
+  end
 end

lib/install/bin/shakapacker-rspack

@@ -0,0 +1,13 @@
+#!/usr/bin/env ruby
+
+ENV["RAILS_ENV"] ||= "development"
+ENV["BUNDLE_GEMFILE"] ||= File.expand_path("../../Gemfile", __FILE__)
+
+require "bundler/setup"
+require "shakapacker"
+require "shakapacker/rspack_runner"
+
+APP_ROOT = File.expand_path("..", __dir__)
+Dir.chdir(APP_ROOT) do
+  Shakapacker::RspackRunner.run(ARGV)
+end

lib/install/config/rspack/rspack.config.js

@@ -0,0 +1,6 @@
+// See the shakacode/shakapacker README and docs directory for advice on customizing your rspackConfig.
+const { generateRspackConfig } = require('shakapacker/rspack')
+
+const rspackConfig = generateRspackConfig()
+
+module.exports = rspackConfig

lib/install/config/shakapacker.yml

@@ -39,6 +39,9 @@ default: &default
   # Select loader to use, available options are 'babel' (default), 'swc' or 'esbuild'
   webpack_loader: 'babel'
 
+  # Select bundler to use, available options are 'webpack' (default) or 'rspack'
+  bundler: 'webpack'
+
   # Raises an error if there is a mismatch in the shakapacker gem and npm package being used
   ensure_consistent_versioning: true
 

lib/install/config/webpack/rspack.config.js

@@ -0,0 +1,6 @@
+// See the shakacode/shakapacker README and docs directory for advice on customizing your rspackConfig.
+const { generateRspackConfig } = require('shakapacker/rspack')
+
+const rspackConfig = generateRspackConfig()
+
+module.exports = rspackConfig

lib/shakapacker/configuration.rb

@@ -88,6 +88,18 @@ def compiler_strategy
     fetch(:compiler_strategy)
   end
 
+  def bundler
+    fetch(:bundler) || "webpack"
+  end
+
+  def rspack?
+    bundler == "rspack"
+  end
+
+  def webpack?
+    bundler == "webpack"
+  end
+
   def fetch(key)
     data.fetch(key, defaults[key])
   end

lib/shakapacker/dev_server_runner.rb

@@ -75,12 +75,20 @@ def execute_cmd
           env["NODE_OPTIONS"] = "#{env["NODE_OPTIONS"]} --inspect-brk --trace-warnings"
         end
 
-        cmd += ["--config", @webpack_config]
-        cmd += ["--progress", "--color"] if @pretty
-
-        # Default behavior of webpack-dev-server is @hot = true
-        cmd += ["--hot", "only"] if @hot == "only"
-        cmd += ["--no-hot"] if !@hot
+        # Add bundler-specific flags and config
+        bundler = get_bundler_type
+        if bundler == "webpack"
+          cmd += ["--config", @webpack_config]
+          cmd += ["--progress", "--color"] if @pretty
+          # Default behavior of webpack-dev-server is @hot = true
+          cmd += ["--hot", "only"] if @hot == "only"
+          cmd += ["--no-hot"] if !@hot
+        elsif bundler == "rspack"
+          # Only add config for rspack if it's not a rspack-specific command
+          cmd += ["--config", @webpack_config]
+          # Rspack supports --hot but not --no-hot or --progress/--color
+          cmd += ["--hot"] if @hot && @hot != false
+        end
 
         cmd += @argv
 
@@ -90,7 +98,9 @@ def execute_cmd
       end
 
       def build_cmd
-        package_json.manager.native_exec_command("webpack", ["serve"])
+        bundler = get_bundler_type
+        command = bundler == "rspack" ? "rspack" : "webpack"
+        package_json.manager.native_exec_command(command, ["serve"])
       end
   end
 end

lib/shakapacker/manifest.rb

@@ -25,6 +25,9 @@ def lookup_pack_with_chunks(name, pack_type = {})
     manifest_pack_name = manifest_name(name, manifest_pack_type)
     find("entrypoints")[manifest_pack_name]["assets"][manifest_pack_type]
   rescue NoMethodError
+    path = find(name)
+    return [path] if path.present?
+
     nil
   end