Revert to Babel transpiler for all files

Using pure Babel configuration (javascript_transpiler: babel) instead of
hybrid Babel/SWC approach. This matches the working master configuration
and should fix RSpec test failures with Stimulus controllers.

We'll investigate SWC compatibility separately after confirming beta.11
works with Babel.

Author: justin808

babel.config.js

@@ -0,0 +1,32 @@
+module.exports = function (api) {
+  const defaultConfigFunc = require('shakapacker/package/babel/preset.js');
+  const resultConfig = defaultConfigFunc(api);
+  const isProductionEnv = api.env('production');
+
+  const changesOnDefault = {
+    presets: [
+      [
+        '@babel/preset-react',
+        {
+          runtime: 'automatic',
+          development: !isProductionEnv,
+          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;
+};

config/shakapacker.yml

@@ -8,7 +8,7 @@ default: &default
   cache_path: tmp/shakapacker
   webpack_compile_output: true
   nested_entries: true
-  javascript_transpiler: swc
+  javascript_transpiler: babel
 
   # Additional paths webpack should lookup modules
   # ['app/assets', 'engine/foo/app/assets']

config/webpack/commonWebpackConfig.js

@@ -69,47 +69,7 @@ if (scssConfigIndex === -1) {
 }
 
 // Copy the object using merge b/c the baseClientWebpackConfig and commonOptions are mutable globals
-const commonWebpackConfig = () => {
-  const config = merge({}, baseClientWebpackConfig, commonOptions, ignoreWarningsConfig);
-
-  // Find the SWC rule and get its include/exclude
-  const swcRuleIndex = config.module.rules.findIndex(rule =>
-    rule.test && /\.(ts|tsx|js|jsx|mjs|coffee)/.test(rule.test.toString())
-  );
-
-  if (swcRuleIndex !== -1) {
-    const swcRule = config.module.rules[swcRuleIndex];
-
-    // Insert Babel rule BEFORE SWC rule so it matches .js files first
-    // This allows Babel to handle all JavaScript while SWC continues to match TypeScript
-    config.module.rules.splice(swcRuleIndex, 0, {
-      test: /\.(js|jsx|mjs)(\.erb)?$/,
-      include: swcRule.include,
-      exclude: swcRule.exclude,
-      use: {
-        loader: 'babel-loader',
-        options: {
-          presets: [
-            ['@babel/preset-env', {
-              useBuiltIns: 'entry',
-              corejs: 3,
-              modules: 'auto',
-              bugfixes: true,
-              exclude: ['transform-typeof-symbol']
-            }],
-            ['@babel/preset-react', {
-              runtime: 'automatic',
-              development: process.env.NODE_ENV !== 'production',
-              useBuiltIns: true
-            }]
-          ]
-        }
-      }
-    });
-  }
-
-  return config;
-};
+const commonWebpackConfig = () => merge({}, baseClientWebpackConfig, commonOptions, ignoreWarningsConfig);
 
 module.exports = commonWebpackConfig;