fix(storybook): remove custom-babel-loader workaround

Author: PaulGMardling

packages/react-components/react-storybook-addon-export-to-sandbox/src/custom-babel-loader.ts

@@ -17,7 +17,7 @@ describe(`webpack`, () => {
         enforce: 'post',
         test: /\.stories\.(jsx?$|tsx?$)/,
         use: {
-          loader: expect.stringContaining('custom-babel-loader'),
+          loader: expect.stringContaining('babel-loader'),
           options: {
             plugins: [
               [
@@ -56,7 +56,7 @@ describe(`webpack`, () => {
         test: /\.stories\.tsx?/,
         include: /foo-stories/,
         use: {
-          loader: expect.stringContaining('custom-babel-loader'),
+          loader: expect.stringContaining('babel-loader'),
           options: {
             plugins: [
               [
@@ -93,7 +93,7 @@ describe(`webpack`, () => {
         enforce: 'post',
         test: /\.stories\.(jsx?$|tsx?$)/,
         use: {
-          loader: expect.stringContaining('custom-babel-loader'),
+          loader: expect.stringContaining('babel-loader'),
           options: {
             plugins: [
               [

packages/react-components/react-storybook-addon-export-to-sandbox/src/webpack.spec.ts

@@ -39,11 +39,7 @@ function createBabelLoaderRule(config: Required<PresetConfig>): import('webpack'
      */
     enforce: 'post',
     use: {
-      /**
-       * Custom babel loader wraps the original babel-loader and fixes the incorrect `inputSourceMap` parameter
-       * that is passed to babel-loader.
-       **/
-      loader: require.resolve('./custom-babel-loader'),
+      loader: require.resolve('babel-loader'),
       options: babelLoaderOptionsUpdater({
         plugins: [plugin],
       }),

packages/react-components/react-storybook-addon-export-to-sandbox/src/webpack.ts

@@ -100,6 +100,10 @@ const swcRule = {
     {
       loader: 'swc-loader',
       options: {
+        // Parse the source map to an object so subsequent loaders (e.g. babel-loader) receive
+        // an object rather than the raw JSON string that @swc/core outputs.
+        // Without this, babel-loader throws: "Error: .inputSourceMap must be a boolean, object, or undefined"
+        parseMap: true,
         jsc: {
           target: 'es2019',
           parser: {