Replace confirm danger modal in remove project fork form

- Adds the shared confirm danger modal trigger
  button to the remove project fork form
- Wire the new modal button to the edit project form 
- Reinstates the remove fork project feature
  spec in `forked_project_settings_spec.rb`

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

 import { PROJECT_BADGE } from '~/badges/constants';
 import initLegacyConfirmDangerModal from '~/confirm_danger_modal';
+import initConfirmDanger from '~/init_confirm_danger';
 import dirtySubmitFactory from '~/dirty_submit/dirty_submit_factory';
 import initFilePickers from '~/file_pickers';
 import mountBadgeSettings from '~/pages/shared/mount_badge_settings';
@@ -15,6 +16,7 @@ import initProjectLoadingSpinner from '../shared/save_project_loader';
 
 initFilePickers();
 initLegacyConfirmDangerModal();
+initConfirmDanger();
 initSettingsPanels();
 initProjectDeleteButton();
 mountBadgeSettings(PROJECT_BADGE);

app/assets/stylesheets/lazy_bundles/select2_overrides.scss

@@ -326,10 +326,6 @@
   }
 }
 
-.transfer-project .select2-container {
-  min-width: 200px;
-}
-
 .right-sidebar {
   .block {
     .select2-container span {

app/controllers/projects_controller.rb

@@ -126,6 +126,8 @@ class ProjectsController < Projects::ApplicationController
     if ::Projects::UnlinkForkService.new(@project, current_user).execute
       flash[:notice] = _('The fork relationship has been removed.')
     end
+
+    redirect_to edit_project_path(@project)
   end
 
   def activity

app/helpers/projects_helper.rb

@@ -120,6 +120,15 @@ module ProjectsHelper
       { project_full_name: project.full_name }
   end
 
+  def remove_fork_project_confirm_json(project, remove_form_id)
+    {
+      remove_form_id: remove_form_id,
+      button_text: _('Remove fork relationship'),
+      confirm_danger_message: remove_fork_project_warning_message(project),
+      phrase: @project.path
+    }
+  end
+
   def visible_fork_source(project)
     project.fork_source if project.fork_source && can?(current_user, :read_project, project.fork_source)
   end

app/views/projects/_remove_fork.html.haml

 - return unless @project.forked? && can?(current_user, :remove_fork_project, @project)
+- remove_form_id = "js-remove-project-fork-form"
 
 .sub-section
   %h4.danger-title= _('Remove fork relationship')
   %p= remove_fork_project_description_message(@project)
 
-  = form_for @project, url: remove_fork_project_path(@project), method: :delete, remote: true, html: { class: 'transfer-project' } do |f|
+  = form_for @project, url: remove_fork_project_path(@project), method: :delete, html: { id: remove_form_id } do |f|
     %p
       %strong= _('Once removed, the fork relationship cannot be restored. This project will no longer be able to receive or send merge requests to the source project or other forks.')
       = link_to _('Learn more.'), help_page_path('user/project/settings/index', anchor: 'removing-a-fork-relationship'), target: '_blank', rel: 'noopener noreferrer'
-    = button_to _('Remove fork relationship'), '#', class: "gl-button btn btn-danger js-legacy-confirm-danger", data: { "confirm-danger-message" => remove_fork_project_warning_message(@project) }
+    .js-confirm-danger{ data: remove_fork_project_confirm_json(@project, remove_form_id) }

app/views/projects/remove_fork.js.haml

-:plain
-    location.href = "#{edit_project_path(@project)}";

spec/controllers/projects_controller_spec.rb

@@ -1092,7 +1092,7 @@ RSpec.describe ProjectsController do
 
           expect(forked_project.reload.forked?).to be_falsey
           expect(flash[:notice]).to eq(s_('The fork relationship has been removed.'))
-          expect(response).to render_template(:remove_fork)
+          expect(response).to redirect_to(edit_project_path(forked_project))
         end
       end
 
@@ -1108,7 +1108,7 @@ RSpec.describe ProjectsController do
               format: :js)
 
           expect(flash[:notice]).to be_nil
-          expect(response).to render_template(:remove_fork)
+          expect(response).to redirect_to(edit_project_path(unforked_project))
         end
       end
     end

spec/features/projects/settings/forked_project_settings_spec.rb

@@ -15,7 +15,7 @@ RSpec.describe 'Projects > Settings > For a forked project', :js do
   end
 
   shared_examples 'project settings for a forked projects' do
-    it 'allows deleting the link to the forked project', quarantine: 'https://gitlab.com/gitlab-org/gitlab/-/issues/327817' do
+    it 'allows deleting the link to the forked project' do
       visit edit_project_path(forked_project)
 
       click_button 'Remove fork relationship'