Fix dropzone project show

app/assets/javascripts/pages/projects/show/index.js

 import $ from 'jquery';
+import initBlob from '~/blob_edit/blob_bundle';
 import ShortcutsNavigation from '~/shortcuts_navigation';
 import NotificationsForm from '~/notifications_form';
 import UserCallout from '~/user_callout';
@@ -19,10 +20,22 @@ document.addEventListener('DOMContentLoaded', () => {
     className: 'js-autodevops-banner',
   });
 
-  if ($('#tree-slider').length) new TreeView(); // eslint-disable-line no-new
-  if ($('.blob-viewer').length) new BlobViewer(); // eslint-disable-line no-new
-  if ($('.project-show-activity').length) new Activities(); // eslint-disable-line no-new
-  $('#tree-slider').waitForImages(() => {
+  // Project show page loads different overview content based on user preferences
+  const treeSlider = document.querySelector('#tree-slider');
+  if (treeSlider) {
+    new TreeView(); // eslint-disable-line no-new
+    initBlob();
+  }
+
+  if (document.querySelector('.blob-viewer')) {
+    new BlobViewer(); // eslint-disable-line no-new
+  }
+
+  if (document.querySelector('.project-show-activity')) {
+    new Activities(); // eslint-disable-line no-new
+  }
+
+  $(treeSlider).waitForImages(() => {
     ajaxGet(document.querySelector('.js-tree-content').dataset.logsPath);
   });
 });

changelogs/unreleased/fix-dropzone-project-show.yml

+---
+title: Fix file upload on project show page
+merge_request:
+author:
+type: fixed

spec/features/projects/show_project_spec.rb

 require 'spec_helper'
 
 describe 'Project show page', :feature do
+  include DropzoneHelper
+
   context 'when project pending delete' do
     let(:project) { create(:project, :empty_repo, pending_delete: true) }
 
@@ -334,4 +336,24 @@ describe 'Project show page', :feature do
       end
     end
   end
+
+  describe 'dropzone', :js do
+    let(:project) { create(:project, :repository) }
+    let(:user) { create(:user) }
+
+    before do
+      project.add_master(user)
+      sign_in(user)
+
+      visit project_path(project)
+    end
+
+    it 'can upload files' do
+      find('.add-to-tree').click
+      click_link 'Upload file'
+      drop_in_dropzone(File.join(Rails.root, 'spec', 'fixtures', 'doc_sample.txt'))
+
+      expect(find('.dz-filename')).to have_content('doc_sample.txt')
+    end
+  end
 end