5 files changed, 73 insertions, 20 deletions
diff --git a/app/controllers/concerns/issuable_actions.rb b/app/controllers/concerns/issuable_actions.rb
index 3ccf2a9ce33..b199f18da1e 100644
--- a/app/controllers/concerns/issuable_actions.rb
+++ b/app/controllers/concerns/issuable_actions.rb
@@ -66,6 +66,7 @@ module IssuableActions
       :milestone_id,
       :state_event,
       :subscription_event,
+      assignee_ids: [],
       label_ids: [],
       add_label_ids: [],
       remove_label_ids: []
diff --git a/app/controllers/concerns/issuable_collections.rb b/app/controllers/concerns/issuable_collections.rb
index c8a501d7319..6df2c068745 100644
--- a/app/controllers/concerns/issuable_collections.rb
+++ b/app/controllers/concerns/issuable_collections.rb
@@ -43,7 +43,7 @@ module IssuableCollections
   end
 
   def issues_collection
-    issues_finder.execute.preload(:project, :author, :assignee, :labels, :milestone, project: :namespace)
+    issues_finder.execute.preload(:project, :author, :assignees, :labels, :milestone, project: :namespace)
   end
 
   def merge_requests_collection
diff --git a/app/controllers/concerns/markdown_preview.rb b/app/controllers/concerns/markdown_preview.rb
deleted file mode 100644
index 40eff267348..00000000000
--- a/app/controllers/concerns/markdown_preview.rb
+++ /dev/null
@@ -1,19 +0,0 @@
-module MarkdownPreview
-  private
-
-  def render_markdown_preview(text, markdown_context = {})
-    render json: {
-      body: view_context.markdown(text, markdown_context),
-      references: {
-        users: preview_referenced_users(text)
-      }
-    }
-  end
-
-  def preview_referenced_users(text)
-    extractor = Gitlab::ReferenceExtractor.new(@project, current_user)
-    extractor.analyze(text, author: current_user)
-
-    extractor.users.map(&:username)
-  end
-end
diff --git a/app/controllers/concerns/notes_actions.rb b/app/controllers/concerns/notes_actions.rb
index c32038d07bf..a57d9e6e6c0 100644
--- a/app/controllers/concerns/notes_actions.rb
+++ b/app/controllers/concerns/notes_actions.rb
@@ -65,6 +65,15 @@ module NotesActions
 
   private
 
+  def note_html(note)
+    render_to_string(
+      "shared/notes/_note",
+      layout: false,
+      formats: [:html],
+      locals: { note: note }
+    )
+  end
+
   def note_json(note)
     attrs = {
       commands_changes: note.commands_changes
@@ -98,6 +107,41 @@ module NotesActions
     attrs
   end
 
+  def diff_discussion_html(discussion)
+    return unless discussion.diff_discussion?
+
+    if params[:view] == 'parallel'
+      template = "discussions/_parallel_diff_discussion"
+      locals =
+        if params[:line_type] == 'old'
+          { discussions_left: [discussion], discussions_right: nil }
+        else
+          { discussions_left: nil, discussions_right: [discussion] }
+        end
+    else
+      template = "discussions/_diff_discussion"
+      locals = { discussions: [discussion] }
+    end
+
+    render_to_string(
+      template,
+      layout: false,
+      formats: [:html],
+      locals: locals
+    )
+  end
+
+  def discussion_html(discussion)
+    return if discussion.individual_note?
+
+    render_to_string(
+      "discussions/_discussion",
+      layout: false,
+      formats: [:html],
+      locals: { discussion: discussion }
+    )
+  end
+
   def authorize_admin_note!
     return access_denied! unless can?(current_user, :admin_note, note)
   end
diff --git a/app/controllers/concerns/uploads_actions.rb b/app/controllers/concerns/uploads_actions.rb
new file mode 100644
index 00000000000..dec2e27335a
--- /dev/null
+++ b/app/controllers/concerns/uploads_actions.rb
@@ -0,0 +1,27 @@
+module UploadsActions
+  def create
+    link_to_file = UploadService.new(model, params[:file], uploader_class).execute
+
+    respond_to do |format|
+      if link_to_file
+        format.json do
+          render json: { link: link_to_file }
+        end
+      else
+        format.json do
+          render json: 'Invalid file.', status: :unprocessable_entity
+        end
+      end
+    end
+  end
+
+  def show
+    return render_404 unless uploader.exists?
+
+    disposition = uploader.image_or_video? ? 'inline' : 'attachment'
+
+    expires_in 0.seconds, must_revalidate: true, private: true
+
+    send_file uploader.file.path, disposition: disposition
+  end
+end