migrate sketch_viewer to dynamic import

app/assets/javascripts/blob/sketch_viewer.js

 /* eslint-disable no-new */
 import SketchLoader from './sketch';
 
-document.addEventListener('DOMContentLoaded', () => {
+export default () => {
   const el = document.getElementById('js-sketch-viewer');
 
   new SketchLoader(el);
-});
+};

app/assets/javascripts/blob/viewer/index.js

@@ -38,6 +38,9 @@ export default class BlobViewer {
       case 'pdf':
         initViewer(import(/* webpackChunkName: 'pdf_viewer' */ '../pdf_viewer'));
         break;
+      case 'sketch':
+        initViewer(import(/* webpackChunkName: 'sketch_viewer' */ '../sketch_viewer'));
+        break;
       default:
         break;
     }

app/views/projects/blob/viewers/_sketch.html.haml

-- content_for :page_specific_javascripts do
-  = webpack_bundle_tag('common_vue')
-  = webpack_bundle_tag('sketch_viewer')
-
 .file-content#js-sketch-viewer{ data: { endpoint: blob_raw_path } }
   .js-loading-icon.text-center.prepend-top-default.append-bottom-default.js-loading-icon{ 'aria-label' => 'Loading Sketch preview' }
     = icon('spinner spin 2x', 'aria-hidden' => 'true');

config/webpack.config.js

@@ -47,7 +47,6 @@ function generateEntries() {
     mr_notes:             './mr_notes/index.js',
     protected_branches:   './protected_branches',
     registry_list:        './registry/index.js',
-    sketch_viewer:        './blob/sketch_viewer.js',
     stl_viewer:           './blob/stl_viewer.js',
     terminal:             './terminal/terminal_bundle.js',
     two_factor_auth:      './two_factor_auth.js',