Upgrade to Shakapacker 9.0.0.beta.11 and migrate to SWC transpiler

- Update shakapacker from 8.2.0 to 9.0.0.beta.11
- Migrate from Babel to SWC transpiler for ~20x faster transpilation
- Remove Babel-related packages and configuration
- Add SWC dependencies (@swc/core, swc-loader)
- Configure SWC in shakapacker.yml for all environments
- Add config/swc.config.js for custom SWC configuration
- Remove babel.config.js as it's no longer needed

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <[email protected]>

Author: justin808

Gemfile.development_dependencies

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-gem "shakapacker", "8.2.0"
+gem "shakapacker", "9.0.0.beta.11"
 gem "bootsnap", require: false
 gem "rails", "~> 7.1"
 

Gemfile.lock

@@ -342,7 +342,7 @@ GEM
       rubyzip (>= 1.2.2, < 3.0)
       websocket (~> 1.0)
     semantic_range (3.1.0)
-    shakapacker (8.2.0)
+    shakapacker (9.0.0.beta.11)
       activesupport (>= 5.2)
       package_json
       rack-proxy (>= 0.6.1)
@@ -440,7 +440,7 @@ DEPENDENCIES
   scss_lint
   sdoc
   selenium-webdriver (= 4.9.0)
-  shakapacker (= 8.2.0)
+  shakapacker (= 9.0.0.beta.11)
   spring (~> 4.0)
   sprockets (~> 4.0)
   sqlite3 (~> 1.6)

spec/dummy/Gemfile.lock

@@ -346,7 +346,7 @@ GEM
       rubyzip (>= 1.2.2, < 3.0)
       websocket (~> 1.0)
     semantic_range (3.1.0)
-    shakapacker (8.2.0)
+    shakapacker (9.0.0.beta.11)
       activesupport (>= 5.2)
       package_json
       rack-proxy (>= 0.6.1)
@@ -441,7 +441,7 @@ DEPENDENCIES
   scss_lint
   sdoc
   selenium-webdriver (= 4.9.0)
-  shakapacker (= 8.2.0)
+  shakapacker (= 9.0.0.beta.11)
   spring (~> 4.0)
   sprockets (~> 4.0)
   sqlite3 (~> 1.6)

spec/dummy/babel.config.js

@@ -1,72 +1,66 @@
-# Note: You must restart bin/shakapacker-dev-server for changes to take effect
-
-default: &default
+---
+default:
   source_path: client/app
   source_entry_path: packs
   public_root_path: public
-
   cache_path: tmp/cache/shakapacker
   webpack_compile_output: false
   ensure_consistent_versioning: true
-
-  # Additional paths webpack should lookup modules
-  # ['app/assets', 'engine/foo/app/assets']
-  additional_paths: []
-
-  # Reload manifest.json on all requests so we reload latest compiled packs
+  additional_paths: &1 []
   cache_manifest: false
   nested_entries: true
-
+  swc: true
 development:
-  <<: *default
-  # Turn this to true if you want to use the rails/shakapacker check that the test
-  # bundles need building. Also, remove the customization to spec/rails_helper.rb.
+  source_path: client/app
+  source_entry_path: packs
+  public_root_path: public
+  cache_path: tmp/cache/shakapacker
+  webpack_compile_output: false
+  ensure_consistent_versioning: true
+  additional_paths: *1
+  cache_manifest: false
+  nested_entries: true
   compile: false
-
   public_output_path: webpack/development
-
-  # Reference: https://webpack.js.org/configuration/dev-server/
   dev_server:
     https: false
     host: localhost
     port: 3035
-    # Hot Module Replacement updates modules while the application is running without a full reload
     hmr: true
-    # Defaults to the inverse of hmr. Uncomment to manually set this.
-    # live_reload: true
     client:
-      # Should we show a full-screen overlay in the browser when there are compiler errors or warnings?
       overlay: true
-      # May also be a string
-      # webSocketURL:
-      #  hostname: "0.0.0.0"
-      #  pathname: "/ws"
-      #  port: 8080
-    # Should we use gzip compression?
     compress: true
-    # Note that apps that do not check the host are vulnerable to DNS rebinding attacks
-    allowed_hosts: 'all'
+    allowed_hosts: all
     pretty: true
     headers:
-      'Access-Control-Allow-Origin': '*'
+      Access-Control-Allow-Origin: "*"
     static:
       watch:
-        ignored: '**/node_modules/**'
-
+        ignored: "**/node_modules/**"
+  swc: true
 test:
-  <<: *default
+  source_path: client/app
+  source_entry_path: packs
+  public_root_path: public
+  cache_path: tmp/cache/shakapacker
+  webpack_compile_output: false
+  ensure_consistent_versioning: true
+  additional_paths: *1
+  cache_manifest: false
+  nested_entries: true
   compile: false
-
-  # Compile test packs to a separate directory
   public_output_path: webpack/test
-
+  swc: true
 production:
-  <<: *default
-
+  source_path: client/app
+  source_entry_path: packs
+  public_root_path: public
+  cache_path: tmp/cache/shakapacker
+  webpack_compile_output: false
+  ensure_consistent_versioning: true
+  additional_paths: *1
+  cache_manifest: true
+  nested_entries: true
   public_output_path: webpack/production
-
-  # Production depends on precompilation of packs prior to booting for performance.
   compile: false
-
-  # Cache manifest.json for performance
-  cache_manifest: true
+  swc: true

spec/dummy/config/shakapacker.yml

@@ -0,0 +1,13 @@
+// config/swc.config.js
+// This file is merged with Shakapacker's default SWC configuration
+// See: https://swc.rs/docs/configuration/compilation
+
+module.exports = {
+  jsc: {
+    transform: {
+      react: {
+        runtime: 'automatic',
+      },
+    },
+  },
+};

spec/dummy/config/swc.config.js

@@ -7,7 +7,6 @@
   },
   "private": true,
   "dependencies": {
-    "@babel/runtime": "7.17.9",
     "@hotwired/turbo-rails": "^8.0.4",
     "core-js": "3",
     "create-react-class": "^15.6.3",
@@ -30,16 +29,11 @@
   },
   "devDependencies": {
     "@babel/core": "7.17.9",
-    "@babel/plugin-transform-runtime": "7.17.0",
-    "@babel/preset-env": "7",
-    "@babel/preset-react": "^7.10.4",
     "@pmmmwh/react-refresh-webpack-plugin": "^0.5.1",
     "@rescript/react": "^0.13.0",
     "@types/react": "^19.0.0",
     "@types/react-dom": "^19.0.0",
     "@types/react-helmet": "^6.1.5",
-    "babel-loader": "8.2.4",
-    "babel-plugin-transform-react-remove-prop-types": "^0.4.24",
     "compression-webpack-plugin": "9",
     "css-loader": "^6.5.1",
     "expose-loader": "^1.0.3",
@@ -59,7 +53,9 @@
     "webpack-assets-manifest": "5",
     "webpack-cli": "4",
     "webpack-dev-server": "^4.9.0",
-    "webpack-merge": "5"
+    "webpack-merge": "5",
+    "@swc/core": "^1.7.39",
+    "swc-loader": "^0.2.6"
   },
   "browser": {
     "fs": false