Render MR Notes with Vue with behind a cookie

5 files changed, 81 insertions, 29 deletions

diff --git a/app/controllers/concerns/issuable_actions.rb b/app/controllers/concerns/issuable_actions.rb
index 337957c366d..a21e658fda1 100644
--- a/app/controllers/concerns/issuable_actions.rb
+++ b/app/controllers/concerns/issuable_actions.rb
@@ -77,6 +77,20 @@ module IssuableActions
     render json: { notice: "#{quantity} #{resource_name.pluralize(quantity)} updated" }
   end
 
+  def discussions
+    notes = issuable.notes
+      .inc_relations_for_view
+      .includes(:noteable)
+      .fresh
+
+    notes = prepare_notes_for_rendering(notes)
+    notes = notes.reject { |n| n.cross_reference_not_visible_for?(current_user) }
+
+    discussions = Discussion.build_collection(notes, issuable)
+
+    render json: DiscussionSerializer.new(project: project, noteable: issuable, current_user: current_user).represent(discussions, context: self)
+  end
+
   private
 
   def recaptcha_check_if_spammable(should_redirect = true, &block)
diff --git a/app/controllers/concerns/notes_actions.rb b/app/controllers/concerns/notes_actions.rb
index e82a5650935..03ed5b5310b 100644
--- a/app/controllers/concerns/notes_actions.rb
+++ b/app/controllers/concerns/notes_actions.rb
@@ -22,7 +22,7 @@ module NotesActions
     notes = notes.reject { |n| n.cross_reference_not_visible_for?(current_user) }
 
     notes_json[:notes] =
-      if noteable.discussions_rendered_on_frontend?
+      if use_note_serializer?
         note_serializer.represent(notes)
       else
         notes.map { |note| note_json(note) }
@@ -95,7 +95,7 @@ module NotesActions
     if note.persisted?
       attrs[:valid] = true
 
-      if noteable.discussions_rendered_on_frontend?
+      if use_note_serializer?
         attrs.merge!(note_serializer.represent(note))
       else
         attrs.merge!(
@@ -233,4 +233,14 @@ module NotesActions
       the_project
     end
   end
+
+  def use_note_serializer?
+    return false if params['html']
+
+    if noteable.is_a?(MergeRequest)
+      cookies[:vue_mr_discussions] == 'true'
+    else
+      noteable.discussions_rendered_on_frontend?
+    end
+  end
 end
diff --git a/app/controllers/projects/discussions_controller.rb b/app/controllers/projects/discussions_controller.rb
index 2e6ab7903b8..ee507009e50 100644
--- a/app/controllers/projects/discussions_controller.rb
+++ b/app/controllers/projects/discussions_controller.rb
@@ -1,4 +1,7 @@
 class Projects::DiscussionsController < Projects::ApplicationController
+  include NotesHelper
+  include RendersNotes
+
   before_action :check_merge_requests_available!
   before_action :merge_request
   before_action :discussion
@@ -7,22 +10,45 @@ class Projects::DiscussionsController < Projects::ApplicationController
   def resolve
     Discussions::ResolveService.new(project, current_user, merge_request: merge_request).execute(discussion)
 
-    render json: {
-      resolved_by: discussion.resolved_by.try(:name),
-      discussion_headline_html: view_to_html_string('discussions/_headline', discussion: discussion)
-    }
+    render_discussion
   end
 
   def unresolve
     discussion.unresolve!
 
+    render_discussion
+  end
+
+  private
+
+  def render_discussion
+    if serialize_notes?
+      # TODO - It is not needed to serialize notes when resolving
+      # or unresolving discussions. We should remove this behavior
+      # passing a parameter to DiscussionEntity to return an empty array
+      # for notes.
+      # Check issue: https://gitlab.com/gitlab-org/gitlab-ce/issues/42853
+      prepare_notes_for_rendering(discussion.notes, merge_request)
+      render_json_with_discussions_serializer
+    else
+      render_json_with_html
+    end
+  end
+
+  def render_json_with_discussions_serializer
+    render json:
+      DiscussionSerializer.new(project: project, noteable: discussion.noteable, current_user: current_user)
+      .represent(discussion, context: self)
+  end
+
+  # Legacy method used to render discussions notes when not using Vue on views.
+  def render_json_with_html
     render json: {
+      resolved_by: discussion.resolved_by.try(:name),
       discussion_headline_html: view_to_html_string('discussions/_headline', discussion: discussion)
     }
   end
 
-  private
-
   def merge_request
     @merge_request ||= MergeRequestsFinder.new(current_user, project_id: @project.id).find_by!(iid: params[:merge_request_id])
   end
diff --git a/app/controllers/projects/issues_controller.rb b/app/controllers/projects/issues_controller.rb
index 73806454525..b14939c4216 100644
--- a/app/controllers/projects/issues_controller.rb
+++ b/app/controllers/projects/issues_controller.rb
@@ -60,20 +60,6 @@ class Projects::IssuesController < Projects::ApplicationController
     respond_with(@issue)
   end
 
-  def discussions
-    notes = @issue.notes
-      .inc_relations_for_view
-      .includes(:noteable)
-      .fresh
-
-    notes = prepare_notes_for_rendering(notes)
-    notes = notes.reject { |n| n.cross_reference_not_visible_for?(current_user) }
-
-    discussions = Discussion.build_collection(notes, @issue)
-
-    render json: DiscussionSerializer.new(project: @project, noteable: @issue, current_user: current_user).represent(discussions)
-  end
-
   def create
     create_params = issue_params.merge(spammable_params).merge(
       merge_request_to_resolve_discussions_of: params[:merge_request_to_resolve_discussions_of],
diff --git a/app/controllers/projects/notes_controller.rb b/app/controllers/projects/notes_controller.rb
index 4f8978c93c3..dd41b9648e8 100644
--- a/app/controllers/projects/notes_controller.rb
+++ b/app/controllers/projects/notes_controller.rb
@@ -1,5 +1,6 @@
 class Projects::NotesController < Projects::ApplicationController
   include NotesActions
+  include NotesHelper
   include ToggleAwardEmoji
 
   before_action :whitelist_query_limiting, only: [:create]
@@ -38,10 +39,14 @@ class Projects::NotesController < Projects::ApplicationController
 
     discussion = note.discussion
 
-    render json: {
-      resolved_by: note.resolved_by.try(:name),
-      discussion_headline_html: (view_to_html_string('discussions/_headline', discussion: discussion) if discussion)
-    }
+    if serialize_notes?
+      render_json_with_notes_serializer
+    else
+      render json: {
+        resolved_by: note.resolved_by.try(:name),
+        discussion_headline_html: (view_to_html_string('discussions/_headline', discussion: discussion) if discussion)
+      }
+    end
   end
 
   def unresolve
@@ -51,16 +56,27 @@ class Projects::NotesController < Projects::ApplicationController
 
     discussion = note.discussion
 
-    render json: {
-      discussion_headline_html: (view_to_html_string('discussions/_headline', discussion: discussion) if discussion)
-    }
+    if serialize_notes?
+      render_json_with_notes_serializer
+    else
+      render json: {
+        discussion_headline_html: (view_to_html_string('discussions/_headline', discussion: discussion) if discussion)
+      }
+    end
   end
 
   private
 
+  def render_json_with_notes_serializer
+    Notes::RenderService.new(current_user).execute([note], project)
+
+    render json: note_serializer.represent(note)
+  end
+
   def note
     @note ||= @project.notes.find(params[:id])
   end
+
   alias_method :awardable, :note
 
   def finder_params