Add backend route for release show page

This commit adds the backend route for the dedicated release show page.
This page is hidden behind a `release_show_page` feature flag which is
disabled by default.

app/controllers/projects/releases_controller.rb

@@ -3,11 +3,12 @@
 class Projects::ReleasesController < Projects::ApplicationController
   # Authorize
   before_action :require_non_empty_project, except: [:index]
-  before_action :release, only: %i[edit update]
+  before_action :release, only: %i[edit show update]
   before_action :authorize_read_release!
   before_action do
     push_frontend_feature_flag(:release_issue_summary, project)
     push_frontend_feature_flag(:release_evidence_collection, project, default_enabled: true)
+    push_frontend_feature_flag(:release_show_page, project)
   end
   before_action :authorize_update_release!, only: %i[edit update]
   before_action :authorize_read_release_evidence!, only: [:evidence]
@@ -29,6 +30,16 @@ class Projects::ReleasesController < Projects::ApplicationController
     end
   end
 
+  def show
+    return render_404 unless Feature.enabled?(:release_show_page, project)
+
+    respond_to do |format|
+      format.html do
+        render :show
+      end
+    end
+  end
+
   protected
 
   def releases
@@ -37,7 +48,9 @@ class Projects::ReleasesController < Projects::ApplicationController
 
   def edit
     respond_to do |format|
-      format.html { render 'edit' }
+      format.html do
+        render :edit
+      end
     end
   end
 

app/views/projects/releases/show.html.haml

+- add_to_breadcrumbs _("Releases"), project_releases_path(@project)
+- page_title @release.name
+
+#js-show-release-page{ data: { project_id: @project.id, tag_name: @release.tag } }

config/routes/project.rb

@@ -166,7 +166,7 @@ constraints(::Constraints::ProjectUrlConstrainer.new) do
           end
         end
 
-        resources :releases, only: [:index, :edit], param: :tag, constraints: { tag: %r{[^/]+} } do
+        resources :releases, only: [:index, :show, :edit], param: :tag, constraints: { tag: %r{[^/]+} } do
           member do
             get :evidence
           end

spec/controllers/projects/releases_controller_spec.rb

@@ -127,13 +127,13 @@ describe Projects::ReleasesController do
       sign_in(user)
     end
 
-    let!(:release) { create(:release, project: project) }
+    let(:release) { create(:release, project: project) }
     let(:tag) { CGI.escape(release.tag) }
 
     it_behaves_like 'successful request'
 
     context 'when tag name contains slash' do
-      let!(:release) { create(:release, project: project, tag: 'awesome/v1.0') }
+      let(:release) { create(:release, project: project, tag: 'awesome/v1.0') }
       let(:tag) { CGI.escape(release.tag) }
 
       it_behaves_like 'successful request'
@@ -145,7 +145,6 @@ describe Projects::ReleasesController do
     end
 
     context 'when release does not exist' do
-      let!(:release) { }
       let(:tag) { 'non-existent-tag' }
 
       it_behaves_like 'not found'
@@ -158,6 +157,47 @@ describe Projects::ReleasesController do
     end
   end
 
+  describe 'GET #show' do
+    subject do
+      get :show, params: { namespace_id: project.namespace, project_id: project, tag: tag }
+    end
+
+    before do
+      sign_in(user)
+    end
+
+    let(:release) { create(:release, project: project) }
+    let(:tag) { CGI.escape(release.tag) }
+
+    it_behaves_like 'successful request'
+
+    context 'when tag name contains slash' do
+      let(:release) { create(:release, project: project, tag: 'awesome/v1.0') }
+      let(:tag) { CGI.escape(release.tag) }
+
+      it_behaves_like 'successful request'
+
+      it 'is accesible at a URL encoded path' do
+        expect(project_release_path(project, release))
+          .to eq("/#{project.namespace.path}/#{project.name}/-/releases/awesome%252Fv1.0")
+      end
+    end
+
+    context 'when feature flag `release_show_page` is disabled' do
+      before do
+        stub_feature_flags(release_show_page: false)
+      end
+
+      it_behaves_like 'not found'
+    end
+
+    context 'when release does not exist' do
+      let(:tag) { 'non-existent-tag' }
+
+      it_behaves_like 'not found'
+    end
+  end
+
   describe 'GET #evidence' do
     let_it_be(:tag_name) { "v1.1.0-evidence" }
     let!(:release) { create(:release, :with_evidence, project: project, tag: tag_name) }