Configure Rollup build with Babel

Author: colinrotherham

package.json

@@ -63,6 +63,7 @@
     "@babel/preset-env": "^7.28.3",
     "@babel/preset-react": "^7.27.1",
     "@babel/preset-typescript": "^7.27.1",
+    "@rollup/plugin-babel": "^6.0.4",
     "@rollup/plugin-commonjs": "^28.0.6",
     "@rollup/plugin-node-resolve": "^16.0.1",
     "@rollup/plugin-typescript": "^12.1.4",

rollup.config.mjs

@@ -1,4 +1,5 @@
 import { join } from 'node:path';
+import { babel } from '@rollup/plugin-babel';
 import commonjs from '@rollup/plugin-commonjs';
 import { nodeResolve } from '@rollup/plugin-node-resolve';
 import typescript from '@rollup/plugin-typescript';
@@ -38,6 +39,9 @@ export default defineConfig(
             outDir: join(outDir, format),
           },
         }),
+        babel({
+          babelHelpers: 'bundled',
+        }),
       ],
     }),
   ),

yarn.lock

@@ -343,16 +343,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@babel/helper-module-imports@npm:^7.22.15, @babel/helper-module-imports@npm:^7.24.1":
-  version: 7.24.3
-  resolution: "@babel/helper-module-imports@npm:7.24.3"
-  dependencies:
-    "@babel/types": "npm:^7.24.0"
-  checksum: 10c0/052c188adcd100f5e8b6ff0c9643ddaabc58b6700d3bbbc26804141ad68375a9f97d9d173658d373d31853019e65f62610239e3295cdd58e573bdcb2fded188d
-  languageName: node
-  linkType: hard
-
-"@babel/helper-module-imports@npm:^7.27.1":
+"@babel/helper-module-imports@npm:^7.18.6, @babel/helper-module-imports@npm:^7.27.1":
   version: 7.27.1
   resolution: "@babel/helper-module-imports@npm:7.27.1"
   dependencies:
@@ -362,6 +353,15 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@babel/helper-module-imports@npm:^7.22.15, @babel/helper-module-imports@npm:^7.24.1":
+  version: 7.24.3
+  resolution: "@babel/helper-module-imports@npm:7.24.3"
+  dependencies:
+    "@babel/types": "npm:^7.24.0"
+  checksum: 10c0/052c188adcd100f5e8b6ff0c9643ddaabc58b6700d3bbbc26804141ad68375a9f97d9d173658d373d31853019e65f62610239e3295cdd58e573bdcb2fded188d
+  languageName: node
+  linkType: hard
+
 "@babel/helper-module-transforms@npm:^7.23.3":
   version: 7.23.3
   resolution: "@babel/helper-module-transforms@npm:7.23.3"
@@ -3555,6 +3555,25 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@rollup/plugin-babel@npm:^6.0.4":
+  version: 6.0.4
+  resolution: "@rollup/plugin-babel@npm:6.0.4"
+  dependencies:
+    "@babel/helper-module-imports": "npm:^7.18.6"
+    "@rollup/pluginutils": "npm:^5.0.1"
+  peerDependencies:
+    "@babel/core": ^7.0.0
+    "@types/babel__core": ^7.1.9
+    rollup: ^1.20.0||^2.0.0||^3.0.0||^4.0.0
+  peerDependenciesMeta:
+    "@types/babel__core":
+      optional: true
+    rollup:
+      optional: true
+  checksum: 10c0/5a7c04fa6d608512b597835e749aef33e129ee9ed6cc9e33489b7d43937358fc8aba48b00819604d0bc9b7c20790a6c035e4136e8d9f70cf0d0f056ba547e700
+  languageName: node
+  linkType: hard
+
 "@rollup/plugin-commonjs@npm:^28.0.6":
   version: 28.0.6
   resolution: "@rollup/plugin-commonjs@npm:28.0.6"
@@ -10639,6 +10658,7 @@ __metadata:
     "@babel/preset-env": "npm:^7.28.3"
     "@babel/preset-react": "npm:^7.27.1"
     "@babel/preset-typescript": "npm:^7.27.1"
+    "@rollup/plugin-babel": "npm:^6.0.4"
     "@rollup/plugin-commonjs": "npm:^28.0.6"
     "@rollup/plugin-node-resolve": "npm:^16.0.1"
     "@rollup/plugin-typescript": "npm:^12.1.4"