shopware/platform

@Tschitt I am getting the same error when I try to import a javascript plugin within my theme in Shopware v6.3.3.0 Stable Version:

Uncaught SyntaxError: Cannot use import statement outside a module

So looks like my main.js under custom/plugins/sw6-theme/src/Resources/app/storefront/src/main.js:

// Import plugins
import RvagTheme from './plugin/theme/theme.plugin';
const PluginManager = window.PluginManager;
PluginManager.register('RvagTheme', RvagTheme);

And so my ./plugin/theme/theme.plugin.js:

import Plugin from 'src/plugin-system/plugin.class';
import deepmerge from 'deepmerge';
export default class RvagTheme extends Plugin {
    static options = deepmerge(FilterBasePlugin.options, {
       // option variables
   });
   init() {
      // init code
   }
}

After running a storefront:build still get the same error.

Starting Execution of 'storefront:build' ('/Applications/.../dev-ops/storefront/actions/build.sh')
(1/4) Starting
> bin/console bundle:dump
     [OK] Dumped plugin configuration.                                              
(2/4) Starting
> PROJECT_ROOT=/Applications/.../  npm --prefix vendor/shopware/platform/src/Storefront/Resources/app/storefront/ run production
    > sw-next-storefront@1.0.0 production /Applications/.../vendor/shopware/platform/src/Storefront/Resources/app/storefront
    > NODE_ENV=production webpack --config webpack.config.js
    # Webpack Plugin Injector: Plugin "Storefront" injected as a new entry point
    # Webpack Plugin Injector: Plugin "RvagTheme" injected as a new entry point
    # Webpack Plugin Injector: Plugin "RvagGeneral" injected as a new entry point
    # Webpack Plugin Injector: Plugin "Ankauf" injected as a new entry point
    Browserslist: caniuse-lite is outdated. Please run next command `npm update`
    ℹ Compiling Shopware 6 Storefront
    ✔ Shopware 6 Storefront: Compiled successfully in 3.06s
       320 modules

It looks like the plugin is being compiled and injected by Webpack (RvagTheme) but still on the frontend is occurring the same error:

Uncaught SyntaxError: Cannot use import statement outside a module

Has anybody already encountered and solved this error?