build: configure Babel with Browserslist

.browserslistrc

@@ -0,0 +1,12 @@
+> 0.1% in GB and not dead
+last 6 Chrome versions
+last 6 Firefox versions
+last 6 Edge versions
+last 2 Samsung versions
+Firefox ESR
+Safari >= 11
+iOS >= 11
+IE 11
+
+[node]
+node 22

babel.config.js

@@ -1,3 +1,19 @@
 module.exports = {
-  presets: ['@babel/preset-env']
+  presets: [
+    [
+      '@babel/preset-env',
+      {
+        // Apply bug fixes to avoid transforms
+        bugfixes: true,
+
+        // Apply smaller "loose" transforms for browsers
+        loose: true
+      }
+    ]
+  ],
+  env: {
+    test: {
+      browserslistEnv: 'node'
+    }
+  }
 }

gulp/tasks/scripts.js

@@ -1,5 +1,6 @@
 const { join, parse } = require('path')
 
+const { babel } = require('@rollup/plugin-babel')
 const commonjs = require('@rollup/plugin-commonjs')
 const nodeResolve = require('@rollup/plugin-node-resolve')
 const terser = require('@rollup/plugin-terser')
@@ -24,7 +25,10 @@ function compileScripts(assetPath, { srcPath, destPath, output = {} }) {
           jquery: 'window.jQuery'
         }),
         nodeResolve(),
-        commonjs()
+        commonjs(),
+        babel({
+          babelHelpers: 'bundled'
+        })
       ]
     })
 

package.json

@@ -52,6 +52,7 @@
     "@babel/preset-env": "^7.26.7",
     "@commitlint/cli": "^18.0.0",
     "@commitlint/config-conventional": "^18.0.0",
+    "@rollup/plugin-babel": "^6.0.4",
     "@rollup/plugin-commonjs": "^28.0.2",
     "@rollup/plugin-node-resolve": "^16.0.0",
     "@rollup/plugin-terser": "^0.4.4",