title: Prestashop Yarn compilation error in module dev
body: <p>I try to developp a module using Prestashop V1.7.7.6 Grid Component.
  I have the html grid on my backoffice module controler but no way to compile webpack by entering &quot;yarn envelop dev&quot;, I have the error :</p>
  <pre><code>Module build failed: ReferenceError: Unknown plugin &quot;transform-object-rest-spread&quot; specified in &quot;/var/www/prestashop/admin-dev/themes/new-theme/.babelrc&quot; at 0, attempted to resolve relative to &quot;/var/www/prestashop/admin-dev/themes/new-theme&quot;
  </code></pre>
  <p>Here is the webpack.conf.js :</p>
  <pre><code>var Encore = require('@symfony/webpack-encore');
  
  Encore
    // directory where compiled assets will be stored
    .setOutputPath('public/build/')
    // public path used by the web server to access the output path
    .setPublicPath('/build')
  
    .addEntry('admin/index', './assets/js/admin/groupsubconf.js')
  
    .cleanupOutputBeforeBuild()
    .enableSourceMaps(!Encore.isProduction())
  ;
  
  module.exports = Encore.getWebpackConfig();
  </code></pre>
  <p>And the package.json</p>
  <pre><code>{
    &quot;devDependencies&quot;: {
      &quot;@symfony/webpack-encore&quot;: &quot;^0.20.1&quot;
    }
  }
  </code></pre>
  <p>And finaly my js file :</p>
  <pre><code>import Grid from '../../../../../admin-dev/themes/new-theme/js/components/grid/grid';
  
  const $ = window.$;
  
  $(document).ready(() =&gt; {
    const theGrid = new Grid('JGroupsubSubConf');
  }
  </code></pre>
  <p>Can someone help me ?</p>
  <p>PS : here the git repo I used <a href="https://github.com/friends-of-presta/masterclass" rel="nofollow noreferrer">https://github.com/friends-of-presta/masterclass</a></p>
  <p>Thanks a lot !</p>