Add swc-loader support for Shakapacker 9.3.0

Shakapacker 9.3.0 defaults to using SWC as the JavaScript transpiler (20x faster than Babel).
This change ensures compatibility by:

- Added @swc/core and swc-loader to spec/dummy/package.json devDependencies
- Updated generator template shakapacker.yml to use javascript_transpiler: "swc" (new setting name)
- Replaced deprecated webpack_loader setting with javascript_transpiler in templates
- Updated yarn.lock after installing new dependencies

This fixes the webpack build error:
"Your Shakapacker config specified using swc, but swc-loader package is not installed"

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

Co-Authored-By: Claude <noreply@anthropic.com>

Author: justin808

lib/generators/react_on_rails/templates/base/base/config/shakapacker.yml

@@ -36,8 +36,10 @@ default: &default
   # Reload manifest.json on all requests so we reload latest compiled packs
   cache_manifest: false
 
-  # Select loader to use, available options are 'babel' (default), 'swc' or 'esbuild'
-  webpack_loader: 'babel'
+  # Select JavaScript transpiler to use
+  # Available options: 'swc' (default, 20x faster), 'babel', or 'esbuild'
+  # Note: When using rspack, swc is used automatically regardless of this setting
+  javascript_transpiler: "swc"
 
   # Raises an error if there is a mismatch in the shakapacker gem and npm package being used
   ensure_consistent_versioning: true

spec/dummy/package.json

@@ -29,6 +29,7 @@
     "regenerator-runtime": "^0.13.4"
   },
   "devDependencies": {
+    "@swc/core": "^1.7.0",
     "@babel/core": "7.17.9",
     "@babel/plugin-transform-runtime": "7.17.0",
     "@babel/preset-env": "7",
@@ -53,6 +54,7 @@
     "sass-resources-loader": "^2.1.0",
     "shakapacker": "9.3.0",
     "style-loader": "^3.3.1",
+    "swc-loader": "^0.2.6",
     "terser-webpack-plugin": "5.3.1",
     "url-loader": "^4.0.0",
     "webpack": "5.72.0",

spec/dummy/yarn.lock

@@ -1362,6 +1362,87 @@
   dependencies:
     "@sinonjs/commons" "^3.0.0"
 
+"@swc/core-darwin-arm64@1.14.0":
+  version "1.14.0"
+  resolved "https://registry.npmjs.org/@swc/core-darwin-arm64/-/core-darwin-arm64-1.14.0.tgz#1db614b52ed7369f47be2a1c6b5e80b6be923898"
+  integrity sha512-uHPC8rlCt04nvYNczWzKVdgnRhxCa3ndKTBBbBpResOZsRmiwRAvByIGh599j+Oo6Z5eyTPrgY+XfJzVmXnN7Q==
+
+"@swc/core-darwin-x64@1.14.0":
+  version "1.14.0"
+  resolved "https://registry.npmjs.org/@swc/core-darwin-x64/-/core-darwin-x64-1.14.0.tgz#900e56924994d0e723e6088e2a2e1a1c08c59a95"
+  integrity sha512-2SHrlpl68vtePRknv9shvM9YKKg7B9T13tcTg9aFCwR318QTYo+FzsKGmQSv9ox/Ua0Q2/5y2BNjieffJoo4nA==
+
+"@swc/core-linux-arm-gnueabihf@1.14.0":
+  version "1.14.0"
+  resolved "https://registry.npmjs.org/@swc/core-linux-arm-gnueabihf/-/core-linux-arm-gnueabihf-1.14.0.tgz#3c84966a8c6e308b0788d1c7875bce23c65134c6"
+  integrity sha512-SMH8zn01dxt809svetnxpeg/jWdpi6dqHKO3Eb11u4OzU2PK7I5uKS6gf2hx5LlTbcJMFKULZiVwjlQLe8eqtg==
+
+"@swc/core-linux-arm64-gnu@1.14.0":
+  version "1.14.0"
+  resolved "https://registry.npmjs.org/@swc/core-linux-arm64-gnu/-/core-linux-arm64-gnu-1.14.0.tgz#5190097d2ca4ea8b198f46a3abe2272331575b54"
+  integrity sha512-q2JRu2D8LVqGeHkmpVCljVNltG0tB4o4eYg+dElFwCS8l2Mnt9qurMCxIeo9mgoqz0ax+k7jWtIRHktnVCbjvQ==
+
+"@swc/core-linux-arm64-musl@1.14.0":
+  version "1.14.0"
+  resolved "https://registry.npmjs.org/@swc/core-linux-arm64-musl/-/core-linux-arm64-musl-1.14.0.tgz#420f510102a37feda0e3dfb8d21651515251476b"
+  integrity sha512-uofpVoPCEUjYIv454ZEZ3sLgMD17nIwlz2z7bsn7rl301Kt/01umFA7MscUovFfAK2IRGck6XB+uulMu6aFhKQ==
+
+"@swc/core-linux-x64-gnu@1.14.0":
+  version "1.14.0"
+  resolved "https://registry.npmjs.org/@swc/core-linux-x64-gnu/-/core-linux-x64-gnu-1.14.0.tgz#953f741d577a81f6e1e1b434856c48eb674cdeb7"
+  integrity sha512-quTTx1Olm05fBfv66DEBuOsOgqdypnZ/1Bh3yGXWY7ANLFeeRpCDZpljD9BSjdsNdPOlwJmEUZXMHtGm3v1TZQ==
+
+"@swc/core-linux-x64-musl@1.14.0":
+  version "1.14.0"
+  resolved "https://registry.npmjs.org/@swc/core-linux-x64-musl/-/core-linux-x64-musl-1.14.0.tgz#bdf241062d1433ba617ffe1451dccde8923a28a2"
+  integrity sha512-caaNAu+aIqT8seLtCf08i8C3/UC5ttQujUjejhMcuS1/LoCKtNiUs4VekJd2UGt+pyuuSrQ6dKl8CbCfWvWeXw==
+
+"@swc/core-win32-arm64-msvc@1.14.0":
+  version "1.14.0"
+  resolved "https://registry.npmjs.org/@swc/core-win32-arm64-msvc/-/core-win32-arm64-msvc-1.14.0.tgz#960919015bc31c46a8fc10df5c384add651df91e"
+  integrity sha512-EeW3jFlT3YNckJ6V/JnTfGcX7UHGyh6/AiCPopZ1HNaGiXVCKHPpVQZicmtyr/UpqxCXLrTgjHOvyMke7YN26A==
+
+"@swc/core-win32-ia32-msvc@1.14.0":
+  version "1.14.0"
+  resolved "https://registry.npmjs.org/@swc/core-win32-ia32-msvc/-/core-win32-ia32-msvc-1.14.0.tgz#826a76b2af0e4df4dee3674e91734cb85eb7b21f"
+  integrity sha512-dPai3KUIcihV5hfoO4QNQF5HAaw8+2bT7dvi8E5zLtecW2SfL3mUZipzampXq5FHll0RSCLzlrXnSx+dBRZIIQ==
+
+"@swc/core-win32-x64-msvc@1.14.0":
+  version "1.14.0"
+  resolved "https://registry.npmjs.org/@swc/core-win32-x64-msvc/-/core-win32-x64-msvc-1.14.0.tgz#75fe708a702f57f176fd640eb9af394cf767be91"
+  integrity sha512-nm+JajGrTqUA6sEHdghDlHMNfH1WKSiuvljhdmBACW4ta4LC3gKurX2qZuiBARvPkephW9V/i5S8QPY1PzFEqg==
+
+"@swc/core@^1.7.0":
+  version "1.14.0"
+  resolved "https://registry.npmjs.org/@swc/core/-/core-1.14.0.tgz#ff7d287fbac6b6fd3adedf7b440cadfd0c389df6"
+  integrity sha512-oExhY90bes5pDTVrei0xlMVosTxwd/NMafIpqsC4dMbRYZ5KB981l/CX8tMnGsagTplj/RcG9BeRYmV6/J5m3w==
+  dependencies:
+    "@swc/counter" "^0.1.3"
+    "@swc/types" "^0.1.25"
+  optionalDependencies:
+    "@swc/core-darwin-arm64" "1.14.0"
+    "@swc/core-darwin-x64" "1.14.0"
+    "@swc/core-linux-arm-gnueabihf" "1.14.0"
+    "@swc/core-linux-arm64-gnu" "1.14.0"
+    "@swc/core-linux-arm64-musl" "1.14.0"
+    "@swc/core-linux-x64-gnu" "1.14.0"
+    "@swc/core-linux-x64-musl" "1.14.0"
+    "@swc/core-win32-arm64-msvc" "1.14.0"
+    "@swc/core-win32-ia32-msvc" "1.14.0"
+    "@swc/core-win32-x64-msvc" "1.14.0"
+
+"@swc/counter@^0.1.3":
+  version "0.1.3"
+  resolved "https://registry.npmjs.org/@swc/counter/-/counter-0.1.3.tgz#cc7463bd02949611c6329596fccd2b0ec782b0e9"
+  integrity sha512-e2BR4lsJkkRlKZ/qCHPw9ZaSxc0MVUd7gtbtaB7aMvHeJVYe8sOB8DBZkP2DtISHGSku9sCK6T6cnY0CtXrOCQ==
+
+"@swc/types@^0.1.25":
+  version "0.1.25"
+  resolved "https://registry.npmjs.org/@swc/types/-/types-0.1.25.tgz#b517b2a60feb37dd933e542d93093719e4cf1078"
+  integrity sha512-iAoY/qRhNH8a/hBvm3zKj9qQ4oc2+3w1unPJa2XvTK3XjeLXtzcCingVPw/9e5mn1+0yPqxcBGp9Jf0pkfMb1g==
+  dependencies:
+    "@swc/counter" "^0.1.3"
+
 "@types/babel__core@^7.1.14":
   version "7.20.5"
   resolved "https://registry.yarnpkg.com/@types/babel__core/-/babel__core-7.20.5.tgz#3df15f27ba85319caa07ba08d0721889bb39c017"
@@ -5968,6 +6049,13 @@ supports-preserve-symlinks-flag@^1.0.0:
   resolved "https://registry.yarnpkg.com/supports-preserve-symlinks-flag/-/supports-preserve-symlinks-flag-1.0.0.tgz#6eda4bd344a3c94aea376d4cc31bc77311039e09"
   integrity sha512-ot0WnXS9fgdkgIcePe6RHNk1WA8+muPa6cSjeR3V8K27q9BB1rTE3R1p7Hv0z1ZyAc8s6Vvv8DIyWf681MAt0w==
 
+swc-loader@^0.2.6:
+  version "0.2.6"
+  resolved "https://registry.npmjs.org/swc-loader/-/swc-loader-0.2.6.tgz#bf0cba8eeff34bb19620ead81d1277fefaec6bc8"
+  integrity sha512-9Zi9UP2YmDpgmQVbyOPJClY0dwf58JDyDMQ7uRc4krmc72twNI2fvlBWHLqVekBpPc7h5NJkGVT1zNDxFrqhvg==
+  dependencies:
+    "@swc/counter" "^0.1.3"
+
 symbol-observable@^1.2.0:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/symbol-observable/-/symbol-observable-1.2.0.tgz#c22688aed4eab3cdc2dfeacbb561660560a00804"