Post-SWC migration cleanup (#678)

Successfully addresses issue #678 with the following improvements:

1. **Babel Dependency Cleanup**
   - Removed unused `babel-loader` (replaced by swc-loader)
   - Removed unused `babel-plugin-macros`
   - Moved `@babel/preset-react` to devDependencies (only needed for Jest/ESLint)
   - Simplified babel.config.js with clear documentation

2. **Documentation**
   - Clarified that Babel is only used for Jest and ESLint
   - Documented that production webpack builds use SWC
   - Added comments explaining configuration choices

**What We Learned:**
- SWC `development` flag causes test failures (needs investigation)
- Test files in client/app/controllers can interfere with RSpec tests
- Dependency cleanup is safe when limited to truly unused packages

Closes #678

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

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

Author: justin808

babel.config.js

@@ -1,32 +1,25 @@
+// Babel config is only used by Jest (babel-jest) and ESLint (@babel/eslint-parser)
+// Production webpack builds use SWC instead (see config/swc.config.js)
 module.exports = function (api) {
   const defaultConfigFunc = require('shakapacker/package/babel/preset.js');
   const resultConfig = defaultConfigFunc(api);
-  const isProductionEnv = api.env('production');
 
+  // Add React preset for Jest testing
+  // Note: @babel/preset-react is in devDependencies since it's only needed for testing
   const changesOnDefault = {
     presets: [
       [
         '@babel/preset-react',
         {
           runtime: 'automatic',
-          development: !isProductionEnv,
+          development: true, // Always use development mode for better test error messages
           useBuiltIns: true,
         },
       ],
-    ].filter(Boolean),
-    plugins: [
-      process.env.WEBPACK_SERVE && 'react-refresh/babel',
-      isProductionEnv && [
-        'babel-plugin-transform-react-remove-prop-types',
-        {
-          removeImport: true,
-        },
-      ],
-    ].filter(Boolean),
+    ],
   };
 
   resultConfig.presets = [...resultConfig.presets, ...changesOnDefault.presets];
-  resultConfig.plugins = [...resultConfig.plugins, ...changesOnDefault.plugins];
 
   return resultConfig;
 };

package.json

@@ -35,7 +35,6 @@
     "@babel/core": "^7.21.0",
     "@babel/plugin-transform-runtime": "^7.21.0",
     "@babel/preset-env": "^7.20.2",
-    "@babel/preset-react": "^7.18.6",
     "@babel/runtime": "^7.17.9",
     "@glennsl/rescript-fetch": "^0.2.0",
     "@glennsl/rescript-json-combinators": "^1.2.1",
@@ -49,8 +48,6 @@
     "ajv": "^8.17.1",
     "autoprefixer": "^10.4.14",
     "axios": "^0.21.1",
-    "babel-loader": "^9.1.2",
-    "babel-plugin-macros": "^3.1.0",
     "babel-plugin-transform-react-remove-prop-types": "^0.4.24",
     "classnames": "^2.3.2",
     "compression-webpack-plugin": "10.0.0",
@@ -110,6 +107,7 @@
   },
   "devDependencies": {
     "@babel/eslint-parser": "^7.16.5",
+    "@babel/preset-react": "^7.18.6",
     "@pmmmwh/react-refresh-webpack-plugin": "^0.5.10",
     "@tailwindcss/typography": "^0.5.10",
     "@webpack-cli/serve": "^2.0.5",

yarn.lock

@@ -953,7 +953,7 @@
     "@babel/plugin-transform-react-jsx-development" "^7.27.1"
     "@babel/plugin-transform-react-pure-annotations" "^7.27.1"
 
-"@babel/runtime@^7.12.1", "@babel/runtime@^7.12.5", "@babel/runtime@^7.17.9", "@babel/runtime@^7.5.5", "@babel/runtime@^7.8.7", "@babel/runtime@^7.9.2":
+"@babel/runtime@^7.12.1", "@babel/runtime@^7.17.9", "@babel/runtime@^7.5.5", "@babel/runtime@^7.8.7", "@babel/runtime@^7.9.2":
   version "7.28.4"
   resolved "https://registry.npmjs.org/@babel/runtime/-/runtime-7.28.4.tgz"
   integrity sha512-Q/N6JNWvIvPnLDvjlE1OUBLPQHH6l3CltCEsHIujp45zQUSSh8K+gHnaEX45yAT1nyngnINhvWtzN+Nb9D8RAQ==
@@ -2186,11 +2186,6 @@
   dependencies:
     undici-types "~7.12.0"
 
-"@types/parse-json@^4.0.0":
-  version "4.0.2"
-  resolved "https://registry.npmjs.org/@types/parse-json/-/parse-json-4.0.2.tgz#5950e50960793055845e956c427fc2b0d70c5239"
-  integrity sha512-dISoDXWWQwUquiKsyZ4Ng+HX2KsPL7LyHKHQwgGFEA3IaKac4Obd+h2a/a6waisAoepJlBcx9paWqjA8/HVjCw==
-
 "@types/prettier@^2.6.0":
   version "2.7.3"
   resolved "https://registry.npmjs.org/@types/prettier/-/prettier-2.7.3.tgz"
@@ -2862,14 +2857,6 @@ babel-jest@^29.5.0, babel-jest@^29.7.0:
     graceful-fs "^4.2.9"
     slash "^3.0.0"
 
-babel-loader@^9.1.2:
-  version "9.2.1"
-  resolved "https://registry.npmjs.org/babel-loader/-/babel-loader-9.2.1.tgz#04c7835db16c246dd19ba0914418f3937797587b"
-  integrity sha512-fqe8naHt46e0yIdkjUZYqddSXfej3AHajX+CSO5X7oy0EmPc6o5Xh+RClNoHjnieWz9AW4kZxW9yyFMhVB1QLA==
-  dependencies:
-    find-cache-dir "^4.0.0"
-    schema-utils "^4.0.0"
-
 babel-plugin-istanbul@^6.1.1:
   version "6.1.1"
   resolved "https://registry.npmjs.org/babel-plugin-istanbul/-/babel-plugin-istanbul-6.1.1.tgz"
@@ -2891,15 +2878,6 @@ babel-plugin-jest-hoist@^29.6.3:
     "@types/babel__core" "^7.1.14"
     "@types/babel__traverse" "^7.0.6"
 
-babel-plugin-macros@^3.1.0:
-  version "3.1.0"
-  resolved "https://registry.npmjs.org/babel-plugin-macros/-/babel-plugin-macros-3.1.0.tgz#9ef6dc74deb934b4db344dc973ee851d148c50c1"
-  integrity sha512-Cg7TFGpIr01vOQNODXOOaGz2NpCU5gl8x1qJFbb6hbZxR7XrcE2vtbAsTAbJ7/xwJtUuJEw8K8Zr/AE0LHlesg==
-  dependencies:
-    "@babel/runtime" "^7.12.5"
-    cosmiconfig "^7.0.0"
-    resolve "^1.19.0"
-
 babel-plugin-polyfill-corejs2@^0.4.14:
   version "0.4.14"
   resolved "https://registry.npmjs.org/babel-plugin-polyfill-corejs2/-/babel-plugin-polyfill-corejs2-0.4.14.tgz"
@@ -3332,11 +3310,6 @@ commander@^8.3.0:
   resolved "https://registry.npmjs.org/commander/-/commander-8.3.0.tgz"
   integrity sha512-OkTL9umf+He2DZkUq8f8J9of7yL6RJKI24dVITBmNfZBmri9zYZQrKkuXiKhyfPSu8tUhnVBB1iKXevvnlR4Ww==
 
-common-path-prefix@^3.0.0:
-  version "3.0.0"
-  resolved "https://registry.npmjs.org/common-path-prefix/-/common-path-prefix-3.0.0.tgz#7d007a7e07c58c4b4d5f433131a19141b29f11e0"
-  integrity sha512-QE33hToZseCH3jS0qN96O/bSh3kaw/h+Tq7ngyY9eWDUnTlTNUyqfqvCXioLe5Na5jFsL78ra/wuBU4iuEgd4w==
-
 common-tags@^1.4.0, common-tags@^1.8.2:
   version "1.8.2"
   resolved "https://registry.npmjs.org/common-tags/-/common-tags-1.8.2.tgz"
@@ -3444,17 +3417,6 @@ core-util-is@~1.0.0:
   resolved "https://registry.npmjs.org/core-util-is/-/core-util-is-1.0.3.tgz"
   integrity sha512-ZQBvi1DcpJ4GDqanjucZ2Hj3wEO5pZDS89BWbkcrvdxksJorwUDDZamX9ldFkp9aw2lmBDLgkObEA4DWNJ9FYQ==
 
-cosmiconfig@^7.0.0:
-  version "7.1.0"
-  resolved "https://registry.npmjs.org/cosmiconfig/-/cosmiconfig-7.1.0.tgz#1443b9afa596b670082ea46cbd8f6a62b84635f6"
-  integrity sha512-AdmX6xUzdNASswsFtmwSt7Vj8po9IuqXm0UXz7QKPuEUmPB4XyjGfaAr2PSuELMwkRMVH1EpIkX5bTZGRB3eCA==
-  dependencies:
-    "@types/parse-json" "^4.0.0"
-    import-fresh "^3.2.1"
-    parse-json "^5.0.0"
-    path-type "^4.0.0"
-    yaml "^1.10.0"
-
 cosmiconfig@^8.2.0:
   version "8.3.6"
   resolved "https://registry.npmjs.org/cosmiconfig/-/cosmiconfig-8.3.6.tgz"
@@ -4650,14 +4612,6 @@ finalhandler@1.3.1:
     statuses "2.0.1"
     unpipe "~1.0.0"
 
-find-cache-dir@^4.0.0:
-  version "4.0.0"
-  resolved "https://registry.npmjs.org/find-cache-dir/-/find-cache-dir-4.0.0.tgz#a30ee0448f81a3990708f6453633c733e2f6eec2"
-  integrity sha512-9ZonPT4ZAK4a+1pUPVPZJapbi7O5qbbJPdYw/NOQWZZbVLdDTYM3A4R9z/DpAM08IDaFGsvPgiGZ82WEwUDWjg==
-  dependencies:
-    common-path-prefix "^3.0.0"
-    pkg-dir "^7.0.0"
-
 find-root@^1.1.0:
   version "1.1.0"
   resolved "https://registry.npmjs.org/find-root/-/find-root-1.1.0.tgz"
@@ -4686,14 +4640,6 @@ find-up@^5.0.0:
     locate-path "^6.0.0"
     path-exists "^4.0.0"
 
-find-up@^6.3.0:
-  version "6.3.0"
-  resolved "https://registry.npmjs.org/find-up/-/find-up-6.3.0.tgz#2abab3d3280b2dc7ac10199ef324c4e002c8c790"
-  integrity sha512-v2ZsoEuVHYy8ZIlYqwPe/39Cy+cFDzp4dXPaxNvkEuouymu+2Jbz0PxpKarJHYJTmv2HWT3O382qY8l4jMWthw==
-  dependencies:
-    locate-path "^7.1.0"
-    path-exists "^5.0.0"
-
 flat-cache@^3.0.4:
   version "3.2.0"
   resolved "https://registry.npmjs.org/flat-cache/-/flat-cache-3.2.0.tgz"
@@ -6169,13 +6115,6 @@ locate-path@^6.0.0:
   dependencies:
     p-locate "^5.0.0"
 
-locate-path@^7.1.0:
-  version "7.2.0"
-  resolved "https://registry.npmjs.org/locate-path/-/locate-path-7.2.0.tgz#69cb1779bd90b35ab1e771e1f2f89a202c2a8a8a"
-  integrity sha512-gvVijfZvn7R+2qyPX8mAuKcFGDf6Nc61GdvGafQsHL0sBIxfKzA+usWn4GFC/bk+QdwPUD4kWFJLhElipq+0VA==
-  dependencies:
-    p-locate "^6.0.0"
-
 lockfile@^1.0.4:
   version "1.0.4"
   resolved "https://registry.npmjs.org/lockfile/-/lockfile-1.0.4.tgz"
@@ -6785,13 +6724,6 @@ p-limit@^3.0.2, p-limit@^3.1.0:
   dependencies:
     yocto-queue "^0.1.0"
 
-p-limit@^4.0.0:
-  version "4.0.0"
-  resolved "https://registry.npmjs.org/p-limit/-/p-limit-4.0.0.tgz#914af6544ed32bfa54670b061cafcbd04984b644"
-  integrity sha512-5b0R4txpzjPWVw/cXXUResoD4hb6U/x9BH08L7nw+GN1sezDzPdxeRvpc9c433fZhBan/wusjbCsqwqm4EIBIQ==
-  dependencies:
-    yocto-queue "^1.0.0"
-
 p-locate@^3.0.0:
   version "3.0.0"
   resolved "https://registry.npmjs.org/p-locate/-/p-locate-3.0.0.tgz"
@@ -6813,13 +6745,6 @@ p-locate@^5.0.0:
   dependencies:
     p-limit "^3.0.2"
 
-p-locate@^6.0.0:
-  version "6.0.0"
-  resolved "https://registry.npmjs.org/p-locate/-/p-locate-6.0.0.tgz#3da9a49d4934b901089dca3302fa65dc5a05c04f"
-  integrity sha512-wPrq66Llhl7/4AGC6I+cqxT07LhXvWL08LNXz1fENOw0Ap4sRZZ/gZpTTJ5jpurzzzfS2W/Ge9BY3LgLjCShcw==
-  dependencies:
-    p-limit "^4.0.0"
-
 p-retry@^4.5.0:
   version "4.6.2"
   resolved "https://registry.npmjs.org/p-retry/-/p-retry-4.6.2.tgz"
@@ -6853,7 +6778,7 @@ parent-module@^1.0.0:
   dependencies:
     callsites "^3.0.0"
 
-parse-json@^5.0.0, parse-json@^5.2.0:
+parse-json@^5.2.0:
   version "5.2.0"
   resolved "https://registry.npmjs.org/parse-json/-/parse-json-5.2.0.tgz#c76fc66dee54231c962b22bcc8a72cf2f99753cd"
   integrity sha512-ayCKvm/phCGxOkYRSCM82iDwct8/EonSEgCSxWxD7ve6jHggsFl4fZVQBPRNgQoKiuV/odhFrGzQXZwbifC8Rg==
@@ -6896,11 +6821,6 @@ path-exists@^4.0.0:
   resolved "https://registry.npmjs.org/path-exists/-/path-exists-4.0.0.tgz"
   integrity sha512-ak9Qy5Q7jYb2Wwcey5Fpvg2KoAc/ZIhLSLOSBmRmygPsGwkVVt0fZa0qrtMz+m6tJTAHfZQ8FnmB4MG4LWy7/w==
 
-path-exists@^5.0.0:
-  version "5.0.0"
-  resolved "https://registry.npmjs.org/path-exists/-/path-exists-5.0.0.tgz#a6aad9489200b21fab31e49cf09277e5116fb9e7"
-  integrity sha512-RjhtfwJOxzcFmNOi6ltcbcu4Iu+FL3zEj83dk4kAS+fVpTxXLO1b38RvJgT/0QwvV/L3aY9TAnyv0EOqW4GoMQ==
-
 path-is-absolute@^1.0.0:
   version "1.0.1"
   resolved "https://registry.npmjs.org/path-is-absolute/-/path-is-absolute-1.0.1.tgz"
@@ -6966,13 +6886,6 @@ pkg-dir@^4.2.0:
   dependencies:
     find-up "^4.0.0"
 
-pkg-dir@^7.0.0:
-  version "7.0.0"
-  resolved "https://registry.npmjs.org/pkg-dir/-/pkg-dir-7.0.0.tgz#8f0c08d6df4476756c5ff29b3282d0bab7517d11"
-  integrity sha512-Ie9z/WINcxxLp27BKOCHGde4ITq9UklYKDzVo1nhk5sqGEXU3FpkwP5GM2voTGJkGd9B3Otl+Q4uwSOeSUtOBA==
-  dependencies:
-    find-up "^6.3.0"
-
 possible-typed-array-names@^1.0.0:
   version "1.1.0"
   resolved "https://registry.npmjs.org/possible-typed-array-names/-/possible-typed-array-names-1.1.0.tgz"
@@ -8019,7 +7932,7 @@ resolve.exports@^2.0.0:
   resolved "https://registry.npmjs.org/resolve.exports/-/resolve.exports-2.0.3.tgz"
   integrity sha512-OcXjMsGdhL4XnbShKpAcSqPMzQoYkYyhbEaeSko47MjRP9NfEQMhZkXL1DoFlt9LWQn4YttrdnV6X2OiyzBi+A==
 
-resolve@^1.1.7, resolve@^1.19.0, resolve@^1.20.0, resolve@^1.22.10, resolve@^1.22.4, resolve@^1.22.8:
+resolve@^1.1.7, resolve@^1.20.0, resolve@^1.22.10, resolve@^1.22.4, resolve@^1.22.8:
   version "1.22.10"
   resolved "https://registry.npmjs.org/resolve/-/resolve-1.22.10.tgz"
   integrity sha512-NPRy+/ncIMeDlTAsuqwKIiferiawhefFJtkNSW0qZJEqMEb+qBt/77B/jGeeek+F0uOeN05CDa6HXbbIgtVX4w==
@@ -9473,11 +9386,6 @@ yallist@^3.0.2:
   resolved "https://registry.npmjs.org/yallist/-/yallist-3.1.1.tgz"
   integrity sha512-a4UGQaWPH59mOXUYnAG2ewncQS4i4F43Tv3JoAM+s2VDAmS9NsK8GpDMLrCHPksFT7h3K6TOoUNn2pb7RoXx4g==
 
-yaml@^1.10.0:
-  version "1.10.2"
-  resolved "https://registry.npmjs.org/yaml/-/yaml-1.10.2.tgz#2301c5ffbf12b467de8da2333a459e29e7920e4b"
-  integrity sha512-r3vXyErRCYJ7wg28yvBY5VSoAF8ZvlcW9/BwUzEtUsjvX/DKs24dIkuwjtuprwJJHsbyUbLApepYTR1BN4uHrg==
-
 yargs-parser@^13.1.2:
   version "13.1.2"
   resolved "https://registry.npmjs.org/yargs-parser/-/yargs-parser-13.1.2.tgz"
@@ -9524,8 +9432,3 @@ yocto-queue@^0.1.0:
   version "0.1.0"
   resolved "https://registry.npmjs.org/yocto-queue/-/yocto-queue-0.1.0.tgz"
   integrity sha512-rVksvsnNCdJ/ohGc6xgPwyN8eheCxsiLM8mxuE/t/mOVqJewPuO1miLpTHQiRgTKCLexL4MeAFVagts7HmNZ2Q==
-
-yocto-queue@^1.0.0:
-  version "1.2.1"
-  resolved "https://registry.npmjs.org/yocto-queue/-/yocto-queue-1.2.1.tgz#36d7c4739f775b3cbc28e6136e21aa057adec418"
-  integrity sha512-AyeEbWOu/TAXdxlV9wmGcR0+yh2j3vYPGOECcIj2S7MkrLyC7ne+oye2BKTItt0ii2PHk4cDy+95+LshzbXnGg==