migrate stl_viewer to dynamic import

app/assets/javascripts/blob/stl_viewer.js

 import Renderer from './3d_viewer';
-document.addEventListener('DOMContentLoaded', () => {
+export default () => {
   const viewer = new Renderer(document.getElementById('js-stl-viewer'));
   [].slice.call(document.querySelectorAll('.js-material-changer')).forEach((el) => {
@@ -16,4 +16,4 @@ document.addEventListener('DOMContentLoaded', () => {
       viewer.changeObjectMaterials(target.dataset.type);
     });
   });
-});
+};

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

@@ -41,6 +41,9 @@ export default class BlobViewer {
       case 'sketch':
         initViewer(import(/* webpackChunkName: 'sketch_viewer' */ '../sketch_viewer'));
         break;
+      case 'stl':
+        initViewer(import(/* webpackChunkName: 'stl_viewer' */ '../stl_viewer'));
+        break;
       default:
         break;
     }

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

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

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',
-    stl_viewer:           './blob/stl_viewer.js',
     terminal:             './terminal/terminal_bundle.js',
     two_factor_auth:      './two_factor_auth.js',