Use ESM exports in copy-files-loader for better webpack optimizations

Author: Kocal

CHANGELOG.md

@@ -121,6 +121,7 @@ can adopt modern async APIs from the ecosystem without hacks**.
 
 - Update postcss-loader support from 8.1.0 to 8.1.1 for ESM compatibility
 - Add support for [webpack-cli@7.0.0](https://github.com/webpack/webpack-cli/releases/tag/webpack-cli%407.0.0)
+- `Encore.copyFiles()` now internally generates ESM exports for better webpack optimizations (scope hoisting, module concatenation)
 
 ## 6.0.0
 

lib/webpack/copy-files-loader.js

@@ -58,7 +58,7 @@ function interpolateName(template, { resourcePath, context, contentHash }) {
  * and customizing output paths using template placeholders.
  *
  * @param {Buffer} source - The raw file content
- * @returns {string} A CommonJS module that exports the public URL of the copied file
+ * @returns {string} An ESM module that exports the public URL of the copied file
  */
 export default function loader(source) {
     const options = this.getOptions();
@@ -82,7 +82,7 @@ export default function loader(source) {
     // "resolve.extensions" parameter of Webpack (for instance
     // if "./test.js" was matched by "./test").
     if (!pattern.test(relativeResourcePath)) {
-        return 'module.exports = "";';
+        return 'export default "";';
     }
 
     // Compute content hash using webpack's built-in hashing utilities
@@ -112,5 +112,5 @@ export default function loader(source) {
     this.emitFile(outputPath, source, null, assetInfo);
 
     // Return a module that exports the public URL
-    return `module.exports = __webpack_public_path__ + ${JSON.stringify(outputPath)};`;
+    return `export default __webpack_public_path__ + ${JSON.stringify(outputPath)};`;
 }