chore: fix babel config (#2714)

babel.config.js

@@ -7,80 +7,81 @@ const isESM = process.env.NODE_ENV === 'esm';
 
 console.log('Build Package:', path.basename(process.cwd()));
 
+const defaultPlugins = [
+  'lodash',
+  [
+    'babel-plugin-transform-builtin-extend',
+    {
+      globals: ['Error'],
+    },
+  ],
+  'transform-export-extensions',
+  '@babel/plugin-proposal-class-properties',
+  '@babel/plugin-proposal-object-rest-spread',
+  '@babel/plugin-proposal-export-default-from',
+  [
+    'module-resolver',
+    isESM
+      ? {
+          root: ['./src'],
+          alias: {
+            coreSrc: './src',
+            Actions: './src/actions',
+            App: './src/components/App',
+            Collection: './src/components/Collection',
+            Constants: './src/constants',
+            Editor: './src/components/Editor',
+            EditorWidgets: './src/components/EditorWidgets',
+            Formats: './src/formats',
+            Integrations: './src/integrations',
+            Lib: './src/lib',
+            MediaLibrary: './src/components/MediaLibrary',
+            Reducers: './src/reducers',
+            ReduxStore: './src/redux',
+            Routing: './src/routing',
+            UI: './src/components/UI',
+            Workflow: './src/components/Workflow',
+            ValueObjects: './src/valueObjects',
+            localforage: 'localforage',
+            redux: 'redux',
+          },
+        }
+      : {
+          root: path.join(__dirname, 'packages/netlify-cms-core/src/components'),
+          alias: {
+            coreSrc: path.join(__dirname, 'packages/netlify-cms-core/src'),
+            Actions: path.join(__dirname, 'packages/netlify-cms-core/src/actions/'),
+            Constants: path.join(__dirname, 'packages/netlify-cms-core/src/constants/'),
+            Formats: path.join(__dirname, 'packages/netlify-cms-core/src/formats/'),
+            Integrations: path.join(__dirname, 'packages/netlify-cms-core/src/integrations/'),
+            Lib: path.join(__dirname, 'packages/netlify-cms-core/src/lib/'),
+            Reducers: path.join(__dirname, 'packages/netlify-cms-core/src/reducers/'),
+            ReduxStore: path.join(__dirname, 'packages/netlify-cms-core/src/redux/'),
+            Routing: path.join(__dirname, 'packages/netlify-cms-core/src/routing/'),
+            ValueObjects: path.join(__dirname, 'packages/netlify-cms-core/src/valueObjects/'),
+            localforage: 'localforage',
+            redux: 'redux',
+          },
+        },
+  ],
+];
+
 const presets = () => {
   return ['@babel/preset-react', '@babel/preset-env'];
 };
 
 const plugins = () => {
-  const defaultPlugins = [
-    'lodash',
-    [
-      'babel-plugin-transform-builtin-extend',
-      {
-        globals: ['Error'],
-      },
-    ],
-    'transform-export-extensions',
-    '@babel/plugin-proposal-class-properties',
-    '@babel/plugin-proposal-object-rest-spread',
-    '@babel/plugin-proposal-export-default-from',
-    [
-      'emotion',
-      {
-        sourceMap: true,
-        autoLabel: true,
-      },
-    ],
-    [
-      'module-resolver',
-      isESM
-        ? {
-            root: ['./src'],
-            alias: {
-              coreSrc: './src',
-              Actions: './src/actions',
-              App: './src/components/App',
-              Collection: './src/components/Collection',
-              Constants: './src/constants',
-              Editor: './src/components/Editor',
-              EditorWidgets: './src/components/EditorWidgets',
-              Formats: './src/formats',
-              Integrations: './src/integrations',
-              Lib: './src/lib',
-              MediaLibrary: './src/components/MediaLibrary',
-              Reducers: './src/reducers',
-              ReduxStore: './src/redux',
-              Routing: './src/routing',
-              UI: './src/components/UI',
-              Workflow: './src/components/Workflow',
-              ValueObjects: './src/valueObjects',
-              localforage: 'localforage',
-              redux: 'redux',
-            },
-          }
-        : {
-            root: path.join(__dirname, 'packages/netlify-cms-core/src/components'),
-            alias: {
-              coreSrc: path.join(__dirname, 'packages/netlify-cms-core/src'),
-              Actions: path.join(__dirname, 'packages/netlify-cms-core/src/actions/'),
-              Constants: path.join(__dirname, 'packages/netlify-cms-core/src/constants/'),
-              Formats: path.join(__dirname, 'packages/netlify-cms-core/src/formats/'),
-              Integrations: path.join(__dirname, 'packages/netlify-cms-core/src/integrations/'),
-              Lib: path.join(__dirname, 'packages/netlify-cms-core/src/lib/'),
-              Reducers: path.join(__dirname, 'packages/netlify-cms-core/src/reducers/'),
-              ReduxStore: path.join(__dirname, 'packages/netlify-cms-core/src/redux/'),
-              Routing: path.join(__dirname, 'packages/netlify-cms-core/src/routing/'),
-              ValueObjects: path.join(__dirname, 'packages/netlify-cms-core/src/valueObjects/'),
-              localforage: 'localforage',
-              redux: 'redux',
-            },
-          },
-    ],
-  ];
 
   if (isESM) {
     return [
       ...defaultPlugins,
+      [
+        'emotion',
+        {
+          sourceMap: true,
+          autoLabel: true,
+        },
+      ],
       [
         'transform-define',
         {
@@ -121,10 +122,29 @@ const plugins = () => {
   }
 
   if (!isProduction) {
-    defaultPlugins.push('react-hot-loader/babel');
+    return [
+      ...defaultPlugins,
+      [
+        'emotion',
+        {
+          sourceMap: true,
+          autoLabel: true,
+        },
+      ],
+      'react-hot-loader/babel',
+    ];
   }
 
-  return defaultPlugins;
+  return [
+    ...defaultPlugins,
+    [
+      'emotion',
+      {
+        sourceMap: true,
+        autoLabel: true,
+      },
+    ],
+  ];
 };
 
 module.exports = {