Add Dependency List view skeleton

Part of the larger [Dependency List MVC][mvc].

This only adds the rails view, from which the client-side application
can bootstrap itself.

[mvc]: https://gitlab.com/gitlab-org/gitlab-ee/issues/10075

app/views/layouts/nav/sidebar/_project.html.haml

@@ -36,6 +36,8 @@
 
           = render_if_exists 'projects/sidebar/security_dashboard'
 
+          = render_if_exists 'projects/sidebar/dependencies'
+
           - if can?(current_user, :read_cycle_analytics, @project)
             = nav_link(path: 'cycle_analytics#show') do
               = link_to project_cycle_analytics_path(@project), title: _('Cycle Analytics'), class: 'shortcuts-project-cycle-analytics' do

ee/app/controllers/projects/dependencies_controller.rb

+# frozen_string_literal: true
+
+module Projects
+  class DependenciesController < Projects::ApplicationController
+    before_action :check_feature_enabled!
+
+    def check_feature_enabled!
+      render_404 unless project.feature_available?(:dependency_list)
+    end
+  end
+end

ee/app/views/projects/dependencies/show.html.haml

+- breadcrumb_title _('Dependency List')
+- page_title _('Dependency List')
+
+#js-dependencies-app{ data: { endpoint: project_security_dependencies_path(@project), documentation_path: help_page_path('user/application_security/dependency_scanning/index'), empty_state_svg_path: image_path('illustrations/Dependency-list-empty-state.svg') } }

ee/app/views/projects/sidebar/_dependencies.html.haml

+- if @project.feature_available?(:dependency_list)
+  = nav_link(path: 'projects/dependencies#show') do
+    = link_to project_dependencies_path(@project), title: _('Dependency List'), class: 'shortcuts-project-dependencies' do
+      %span= _('Dependency List')

ee/changelogs/unreleased/11396-dependency-list-connect-frontend-to-backend-ee.yml

+---
+title: Add preliminary Dependency List frontend implementation.
+merge_request: 13968
+author:
+type: added

ee/config/routes/project.rb

@@ -83,6 +83,8 @@ constraints(::Constraints::ProjectUrlConstrainer.new) do
         end
       end
 
+      resource :dependencies, only: [:show]
+
       namespace :security do
         resources :dependencies, only: [:index]
       end

ee/spec/controllers/projects/dependencies_controller_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Projects::DependenciesController do
+  set(:project) { create(:project, :repository, :public) }
+  set(:user) { create(:user) }
+
+  subject { get :show, params: { namespace_id: project.namespace, project_id: project } }
+
+  before do
+    project.add_developer(user)
+  end
+
+  describe 'GET show' do
+    context 'with authorized user' do
+      before do
+        sign_in(user)
+      end
+
+      context 'when feature is available' do
+        before do
+          stub_licensed_features(dependency_list: true)
+        end
+
+        it 'renders the show template' do
+          subject
+
+          expect(response).to have_gitlab_http_status(200)
+          expect(response).to render_template(:show)
+        end
+      end
+
+      context 'when feature is not available' do
+        it 'returns 404' do
+          subject
+
+          expect(response).to have_gitlab_http_status(404)
+        end
+      end
+    end
+
+    context 'with unauthorized user' do
+      it 'returns 404' do
+        subject
+
+        expect(response).to have_gitlab_http_status(404)
+      end
+    end
+  end
+end

locale/gitlab.pot

@@ -4093,6 +4093,9 @@ msgstr ""
 msgid "Dependencies|Version"
 msgstr ""
 
+msgid "Dependency List"
+msgstr ""
+
 msgid "Dependency Proxy"
 msgstr ""