Fix HTTP status code for Todos API when an epic cannot be found

Signed-off-by: Rémy Coutable <remy@rymai.me>

ee/changelogs/unreleased/fix-http-status-code-in-epic-todos-api.yml

+---
+title: Fix HTTP status code for Todos API when an epic cannot be found
+merge_request: 28310
+author:
+type: fixed

ee/lib/ee/api/helpers.rb

@@ -104,12 +104,9 @@ module EE
         end
       end
 
-      override :find_project_issue
       # rubocop: disable CodeReuse/ActiveRecord
-      def find_project_issue(iid, project_id = nil)
-        project = project_id ? find_project!(project_id) : user_project
-
-        ::IssuesFinder.new(current_user, project_id: project.id).find_by!(iid: iid)
+      def find_group_epic(iid)
+        EpicsFinder.new(current_user, group_id: user_group.id).find_by!(iid: iid)
       end
       # rubocop: enable CodeReuse/ActiveRecord
 

ee/lib/ee/api/todos.rb

@@ -9,14 +9,8 @@ module EE
         helpers do
           extend ::Gitlab::Utils::Override
 
-          # rubocop: disable CodeReuse/ActiveRecord
-          def epic
-            @epic ||= user_group.epics.find_by(iid: params[:epic_iid])
-          end
-          # rubocop: enable CodeReuse/ActiveRecord
-
           def authorize_can_read!
-            authorize!(:read_epic, epic)
+            authorize!(:read_epic, user_group)
           end
         end
 
@@ -29,6 +23,7 @@ module EE
           end
           post ":id/epics/:epic_iid/todo" do
             authorize_can_read!
+            epic = find_group_epic(params[:epic_iid])
             todo = ::TodoService.new.mark_todo(epic, current_user).first
 
             if todo

ee/spec/requests/api/todos_spec.rb

@@ -142,7 +142,7 @@ describe API::Todos do
 
         post api("/groups/#{group.id}/epics/#{non_existing_record_iid}/todo", user)
 
-        expect(response).to have_gitlab_http_status(:forbidden)
+        expect(response).to have_gitlab_http_status(:not_found)
       end
 
       it 'returns an error if the epic is not accessible' do

lib/api/helpers.rb

@@ -179,8 +179,10 @@ module API
     end
 
     # rubocop: disable CodeReuse/ActiveRecord
-    def find_project_issue(iid)
-      IssuesFinder.new(current_user, project_id: user_project.id).find_by!(iid: iid)
+    def find_project_issue(iid, project_id = nil)
+      project = project_id ? find_project!(project_id) : user_project
+
+      ::IssuesFinder.new(current_user, project_id: project.id).find_by!(iid: iid)
     end
     # rubocop: enable CodeReuse/ActiveRecord