Use feature flags for notes and award emojis

This allows us to disable creating/updating/removing of notes as well as
toggling of award emojis.

app/controllers/application_controller.rb

@@ -366,6 +366,14 @@ class ApplicationController < ActionController::Base
     request.base_url
   end
+  def require_feature!(feature)
+    if Gitlab::Feature.feature_enabled?(feature)
+      yield
+    else
+      head(:service_unavailable)
+    end
+  end
+
   private
   def set_default_sort

app/controllers/concerns/toggle_award_emoji.rb

@@ -6,12 +6,14 @@ module ToggleAwardEmoji
   end
   def toggle_award_emoji
-    name = params.require(:name)
-    awardable.toggle_award_emoji(name, current_user)
-    TodoService.new.new_award_emoji(to_todoable(awardable), current_user)
-    render json: { ok: true }
+    require_feature!(:toggling_award_emoji) do
+      name = params.require(:name)
+      awardable.toggle_award_emoji(name, current_user)
+      TodoService.new.new_award_emoji(to_todoable(awardable), current_user)
+      render json: { ok: true }
+    end
   end
   private

app/controllers/projects/notes_controller.rb

@@ -22,39 +22,47 @@ class Projects::NotesController < Projects::ApplicationController
   end
   def create
-    @note = Notes::CreateService.new(project, current_user, note_params).execute
-    respond_to do |format|
-      format.json { render json: note_json(@note) }
-      format.html { redirect_back_or_default }
+    require_feature!(:creating_notes) do
+      @note = Notes::CreateService.new(project, current_user, note_params).execute
+      respond_to do |format|
+        format.json { render json: note_json(@note) }
+        format.html { redirect_back_or_default }
+      end
     end
   end
   def update
-    @note = Notes::UpdateService.new(project, current_user, note_params).execute(note)
-    respond_to do |format|
-      format.json { render json: note_json(@note) }
-      format.html { redirect_back_or_default }
+    require_feature!(:updating_notes) do
+      @note = Notes::UpdateService.new(project, current_user, note_params).execute(note)
+      respond_to do |format|
+        format.json { render json: note_json(@note) }
+        format.html { redirect_back_or_default }
+      end
     end
   end
   def destroy
-    if note.editable?
-      Notes::DeleteService.new(project, current_user).execute(note)
-    end
-
-    respond_to do |format|
-      format.js { head :ok }
+    require_feature!(:removing_notes) do
+      if note.editable?
+        Notes::DeleteService.new(project, current_user).execute(note)
+      end
+
+      respond_to do |format|
+        format.js { head :ok }
+      end
     end
   end
   def delete_attachment
-    note.remove_attachment!
-    note.update_attribute(:attachment, nil)
-    respond_to do |format|
-      format.js { head :ok }
+    require_feature!(:removing_note_attachments) do
+      note.remove_attachment!
+      note.update_attribute(:attachment, nil)
+      respond_to do |format|
+        format.js { head :ok }
+      end
     end
   end

app/views/award_emoji/_awards_block.html.haml

 - grouped_emojis = awardable.grouped_awards(with_thumbs: inline)
 .awards.js-awards-block{ class: ("hidden" if !inline && grouped_emojis.empty?), data: { award_url: url_for([:toggle_award_emoji, @project.namespace.becomes(Namespace), @project, awardable]) } }
   - awards_sort(grouped_emojis).each do |emoji, awards|
-    %button.btn.award-control.js-emoji-btn.has-tooltip{ type: "button", class: (award_active_class(awards, current_user)), data: { placement: "bottom", title: award_user_list(awards, current_user) } }
+    %button.btn.award-control.js-emoji-btn.has-tooltip{ disabled: !Gitlab::Feature.toggling_award_emoji_enabled?, type: "button", class: (award_active_class(awards, current_user)), data: { placement: "bottom", title: award_user_list(awards, current_user) } }
       = emoji_icon(emoji, sprite: false)
       %span.award-control-text.js-counter
         = awards.count
-  - if current_user
+  - if current_user && Gitlab::Feature.toggling_award_emoji_enabled?
     .award-menu-holder.js-award-holder
       %button.btn.award-control.js-add-award{ type: "button" }
         = icon('smile-o', class: "award-control-icon award-control-icon-normal")

app/views/projects/diffs/_line.html.haml

@@ -15,7 +15,7 @@
         = link_text
       - else
         = link_to "", "##{line_code}", id: line_code, data: { linenumber: link_text }
-      - if !@diff_notes_disabled && can?(current_user, :create_note, @project)
+      - if !@diff_notes_disabled && can?(current_user, :create_note, @project) && Gitlab::Feature.creating_notes_enabled?
         = link_to_new_diff_note(line_code)
     %td.new_line.diff-line-num{ class: type, data: { linenumber: line.new_pos } }
       - link_text = type == "old" ? " ".html_safe : line.new_pos

app/views/projects/notes/_note.html.haml

@@ -21,20 +21,22 @@
           - if access
             %span.note-role.hidden-xs= access
           - if current_user
-            = link_to '#', title: 'Award Emoji', class: 'note-action-button note-emoji-button js-add-award js-note-emoji', data: { position: 'right' } do
-              = icon('spinner spin')
-              = icon('smile-o')
-          - if note_editable
+            - if Gitlab::Feature.toggling_award_emoji_enabled?
+              = link_to '#', title: 'Award Emoji', class: 'note-action-button note-emoji-button js-add-award js-note-emoji', data: { position: 'right' } do
+                = icon('spinner spin')
+                = icon('smile-o')
+          - if note_editable && Gitlab::Feature.updating_notes_enabled?
             = link_to '#', title: 'Edit comment', class: 'note-action-button js-note-edit' do
               = icon('pencil')
-            = link_to namespace_project_note_path(note.project.namespace, note.project, note), title: 'Remove comment', method: :delete, data: { confirm: 'Are you sure you want to remove this comment?' }, remote: true, class: 'note-action-button hidden-xs js-note-delete danger' do
-              = icon('trash-o')
+            - if Gitlab::Feature.removing_notes_enabled?
+              = link_to namespace_project_note_path(note.project.namespace, note.project, note), title: 'Remove comment', method: :delete, data: { confirm: 'Are you sure you want to remove this comment?' }, remote: true, class: 'note-action-button hidden-xs js-note-delete danger' do
+                = icon('trash-o')
       .note-body{class: note_editable ? 'js-task-list-container' : ''}
         .note-text
           = preserve do
             = markdown(note.note, pipeline: :note, cache_key: [note, "note"], author: note.author)
           = edited_time_ago_with_tooltip(note, placement: 'bottom', html_class: 'note_edited_ago', include_author: true)
-        - if note_editable
+        - if note_editable && Gitlab::Feature.updating_notes_enabled?
           = render 'projects/notes/edit_form', note: note
         .note-awards
           = render 'award_emoji/awards_block', awardable: note, inline: false

app/views/projects/notes/_notes_with_form.html.haml

@@ -2,20 +2,25 @@
   = render "projects/notes/notes"
 %ul.notes.notes-form.timeline
   %li.timeline-entry
-    - if can? current_user, :create_note, @project
-      .timeline-icon.hidden-xs.hidden-sm
-        %a.author_link{ href: user_path(current_user) }
-          = image_tag avatar_icon(current_user), alt: current_user.to_reference, class: 'avatar s40'
-      .timeline-content.timeline-content-form
-        = render "projects/notes/form", view: diff_view
+    - if Gitlab::Feature.creating_notes_enabled?
+      - if can? current_user, :create_note, @project
+        .timeline-icon.hidden-xs.hidden-sm
+          %a.author_link{ href: user_path(current_user) }
+            = image_tag avatar_icon(current_user), alt: current_user.to_reference, class: 'avatar s40'
+        .timeline-content.timeline-content-form
+          = render "projects/notes/form", view: diff_view
+      - else
+        .disabled-comment.text-center
+          .disabled-comment-text.inline
+            Please
+            = link_to "register",new_user_session_path
+            or
+            = link_to "login",new_user_session_path
+            to post a comment
     - else
       .disabled-comment.text-center
         .disabled-comment-text.inline
-          Please
-          = link_to "register",new_user_session_path
-          or
-          = link_to "login",new_user_session_path
-          to post a comment
+          Creating comments is currently disabled.
 :javascript
   var notes = new Notes("#{namespace_project_notes_path(namespace_id: @project.namespace, target_id: @noteable.id, target_type: @noteable.class.name.underscore)}", #{@notes.map(&:id).to_json}, #{Time.now.to_i}, "#{diff_view}")

lib/api/helpers.rb

@@ -281,6 +281,12 @@ module API
       error!({ 'message' => message }, status)
     end
+    def require_feature!(feature)
+      unless Gitlab::Feature.feature_enabled?(feature)
+        render_api_error!('503 Service Unavailable', 503)
+      end
+    end
+
     # Projects helpers
     def filter_projects(projects)

lib/api/notes.rb

@@ -71,6 +71,7 @@ module API
         #   POST /projects/:id/issues/:noteable_id/notes
         #   POST /projects/:id/snippets/:noteable_id/notes
         post ":id/#{noteables_str}/:#{noteable_id_str}/notes" do
+          require_feature! :creating_notes
           required_attributes! [:body]
           opts = {
@@ -103,6 +104,7 @@ module API
         #   PUT /projects/:id/issues/:noteable_id/notes/:note_id
         #   PUT /projects/:id/snippets/:noteable_id/notes/:node_id
         put ":id/#{noteables_str}/:#{noteable_id_str}/notes/:note_id" do
+          require_feature! :updating_notes
           required_attributes! [:body]
           note = user_project.notes.find(params[:note_id])
@@ -132,6 +134,7 @@ module API
         #   DELETE /projects/:id/issues/:noteable_id/notes/:note_id
         #   DELETE /projects/:id/snippets/:noteable_id/notes/:node_id
         delete ":id/#{noteables_str}/:#{noteable_id_str}/notes/:note_id" do
+          require_feature! :removing_notes
           note = user_project.notes.find(params[:note_id])
           authorize! :admin_note, note

spec/controllers/projects/notes_controller_spec.rb

@@ -4,7 +4,50 @@ describe Projects::NotesController do
   let(:user)    { create(:user) }
   let(:project) { create(:project) }
   let(:issue)   { create(:issue, project: project) }
-  let(:note)    { create(:note, noteable: issue, project: project) }
+  let(:note)    { create(:note, noteable: issue, project: project, author: user) }
+
+  describe 'POST #create' do
+    before do
+      sign_in(user)
+      project.team << [user, :developer]
+    end
+
+    context 'when creating notes is disabled' do
+      it 'responds with a service unavailable error' do
+        expect(Gitlab::Feature).to receive(:feature_enabled?).
+          with(:creating_notes).
+          and_return(false)
+
+        post(:create,
+            namespace_id: project.namespace.path,
+            project_id: project.path)
+
+        expect(response.status).to eq(503)
+      end
+    end
+  end
+
+  describe 'PUT #update' do
+    before do
+      sign_in(user)
+      project.team << [user, :developer]
+    end
+
+    context 'when updating notes is disabled' do
+      it 'responds with a service unavailable error' do
+        expect(Gitlab::Feature).to receive(:feature_enabled?).
+          with(:updating_notes).
+          and_return(false)
+
+        put(:update,
+           namespace_id: project.namespace.path,
+           project_id: project.path,
+           id: note.id)
+
+        expect(response.status).to eq(503)
+      end
+    end
+  end
   describe 'POST #toggle_award_emoji' do
     before do
@@ -32,5 +75,18 @@ describe Projects::NotesController do
       expect(response.status).to eq(200)
     end
+
+    context 'when toggling award emoji is disabled' do
+      it 'responds with a service unavailable error' do
+        expect(Gitlab::Feature).to receive(:feature_enabled?).
+          with(:toggling_award_emoji).
+          and_return(false)
+
+        post(:toggle_award_emoji, namespace_id: project.namespace.path,
+                                  project_id: project.path, id: note.id, name: "thumbsup")
+
+        expect(response.status).to eq(503)
+      end
+    end
   end
 end

spec/requests/api/notes_spec.rb

@@ -266,6 +266,18 @@ describe API::API, api: true  do
         expect(private_issue.notes.reload).to be_empty
       end
     end
+
+    context 'when creating notes is disabled' do
+      it 'responds with a service unavailable error' do
+        expect(Gitlab::Feature).to receive(:feature_enabled?).
+          with(:creating_notes).
+          and_return(false)
+
+        post api("/projects/#{project.id}/issues/#{issue.id}/notes", user), body: 'hi!'
+
+        expect(response.status).to eq(503)
+      end
+    end
   end
   describe "POST /projects/:id/noteable/:noteable_id/notes to test observer on create" do
@@ -334,6 +346,19 @@ describe API::API, api: true  do
         expect(response.status).to eq(404)
       end
     end
+
+    context 'when updating notes is disabled' do
+      it 'responds with a service unavailable error' do
+        expect(Gitlab::Feature).to receive(:feature_enabled?).
+          with(:updating_notes).
+          and_return(false)
+
+        put api("/projects/#{project.id}/issues/#{issue.id}/notes/"\
+                "#{issue_note.id}", user), body: 'hi!'
+
+        expect(response.status).to eq(503)
+      end
+    end
   end
   describe 'DELETE /projects/:id/noteable/:noteable_id/notes/:note_id' do
@@ -395,6 +420,19 @@ describe API::API, api: true  do
         expect(response.status).to eq(404)
       end
     end
+
+    context 'when deleting notes is disabled' do
+      it 'responds with a service unavailable error' do
+        expect(Gitlab::Feature).to receive(:feature_enabled?).
+          with(:removing_notes).
+          and_return(false)
+
+        delete api("/projects/#{project.id}/issues/#{issue.id}/notes/"\
+                "#{issue_note.id}", user)
+
+        expect(response.status).to eq(503)
+      end
+    end
   end
 end