Fix

packages/lightningcss-loader/index.js

@@ -1,4 +1,4 @@
-const lightningcssLoader = (source, sourceMap) => {
+const lightningcssLoader = function (source, sourceMap) {
     const { implementation, ...options } = this.getOptions();
     const callback = this.async();
 
@@ -17,6 +17,6 @@ const lightningcssLoader = (source, sourceMap) => {
     });
 
     callback(undefined, code.toString(), map && JSON.parse(map.toString()));
-}
+};
 
 export default lightningcssLoader;