API: Respect the 'If-Unmodified-Since' for delete endpoints

lib/api/access_requests.rb

@@ -67,6 +67,9 @@ class AccessRequests < Grape::API
         end
         delete ":id/access_requests/:user_id" do
           source = find_source(source_type, params[:id])
+          member = source.public_send(:requesters).find_by!(user_id: params[:user_id])
+
+          check_unmodified_since(member.updated_at)
           status 204
           ::Members::DestroyService.new(source, current_user, params)

lib/api/award_emoji.rb

@@ -85,6 +85,7 @@ class AwardEmoji < Grape::API
           end
           delete "#{endpoint}/:award_id" do
             award = awardable.award_emoji.find(params[:award_id])
+            check_unmodified_since(award.updated_at)
             unauthorized! unless award.user == current_user || current_user.admin?

lib/api/boards.rb

@@ -118,6 +118,7 @@ def board_lists
           authorize!(:admin_list, user_project)
           list = board_lists.find(params[:list_id])
+          check_unmodified_since(list.updated_at)
           service = ::Boards::Lists::DestroyService.new(user_project, current_user)

lib/api/broadcast_messages.rb

@@ -90,6 +90,7 @@ def find_message
       end
       delete ':id' do
         message = find_message
+        check_unmodified_since(message.updated_at)
         status 204
         message.destroy

lib/api/deploy_keys.rb

@@ -125,6 +125,8 @@ class DeployKeys < Grape::API
         key = user_project.deploy_keys_projects.find_by(deploy_key_id: params[:key_id])
         not_found!('Deploy Key') unless key
+        check_unmodified_since(key.updated_at)
+
         status 204
         key.destroy
       end

lib/api/environments.rb

@@ -78,6 +78,7 @@ class Environments < Grape::API
         authorize! :update_environment, user_project
         environment = user_project.environments.find(params[:environment_id])
+        check_unmodified_since(environment.updated_at)
         status 204
         environment.destroy

lib/api/groups.rb

@@ -149,6 +149,8 @@ def present_groups(groups, options = {})
       delete ":id" do
         group = find_group!(params[:id])
         authorize! :admin_group, group
+        
+        check_unmodified_since(group.updated_at)
         status 204
         ::Groups::DestroyService.new(group, current_user).execute

lib/api/helpers.rb

@@ -13,6 +13,14 @@ def declared_params(options = {})
       declared(params, options).to_h.symbolize_keys
     end
+    def check_unmodified_since(last_modified)
+      if_unmodified_since = Time.parse(headers['If-Unmodified-Since']) if headers.key?('If-Unmodified-Since') rescue nil
+
+      if if_unmodified_since && if_unmodified_since < last_modified
+        render_api_error!('412 Precondition Failed', 412)
+      end
+    end
+
     def current_user
       return @current_user if defined?(@current_user)

lib/api/issues.rb

@@ -236,6 +236,8 @@ def find_issues(args = {})
         not_found!('Issue') unless issue
         authorize!(:destroy_issue, issue)
+        check_unmodified_since(issue.updated_at)
+
         status 204
         issue.destroy
       end

lib/api/labels.rb

@@ -56,6 +56,8 @@ class Labels < Grape::API
         label = user_project.labels.find_by(title: params[:name])
         not_found!('Label') unless label
+        check_unmodified_since(label.updated_at)
+
         status 204
         label.destroy
       end

lib/api/members.rb

@@ -99,8 +99,9 @@ class Members < Grape::API
         end
         delete ":id/members/:user_id" do
           source = find_source(source_type, params[:id])
-          # Ensure the member exists
-          source.members.find_by!(user_id: params[:user_id])
+          # Ensure that memeber exists
+          member = source.members.find_by!(user_id: params[:user_id])
+          check_unmodified_since(member.updated_at)
           status 204
           ::Members::DestroyService.new(source, current_user, declared_params).execute

lib/api/merge_requests.rb

@@ -193,6 +193,8 @@ def find_merge_requests(args = {})
         merge_request = find_project_merge_request(params[:merge_request_iid])
         authorize!(:destroy_merge_request, merge_request)
+        check_unmodified_since(merge_request.updated_at)
+
         status 204
         merge_request.destroy
       end

lib/api/notes.rb

@@ -129,7 +129,9 @@ class Notes < Grape::API
         end
         delete ":id/#{noteables_str}/:noteable_id/notes/:note_id" do
           note = user_project.notes.find(params[:note_id])
+
           authorize! :admin_note, note
+          check_unmodified_since(note.updated_at)
           status 204
           ::Notes::DestroyService.new(user_project, current_user).execute(note)

lib/api/project_hooks.rb

@@ -96,6 +96,8 @@ class ProjectHooks < Grape::API
       delete ":id/hooks/:hook_id" do
         hook = user_project.hooks.find(params.delete(:hook_id))
+        check_unmodified_since(hook.updated_at)
+
         status 204
         hook.destroy
       end

lib/api/project_snippets.rb

@@ -116,6 +116,8 @@ def snippets_for_current_user
         not_found!('Snippet') unless snippet
         authorize! :admin_project_snippet, snippet
+        check_unmodified_since(snippet.updated_at)
+
         status 204
         snippet.destroy
       end

lib/api/projects.rb

@@ -346,6 +346,8 @@ def present_projects(options = {})
       desc 'Remove a project'
       delete ":id" do
         authorize! :remove_project, user_project
+        check_unmodified_since(user_project.updated_at)
+
         ::Projects::DestroyService.new(user_project, current_user, {}).async_execute
         accepted!

lib/api/runners.rb

@@ -77,7 +77,9 @@ class Runners < Grape::API
       end
       delete ':id' do
         runner = get_runner(params[:id])
+
         authenticate_delete_runner!(runner)
+        check_unmodified_since(runner.updated_at)
         status 204
         runner.destroy!

lib/api/services.rb

@@ -703,6 +703,8 @@ def service_attributes(service)
       end
       delete ":id/services/:service_slug" do
         service = user_project.find_or_initialize_service(params[:service_slug].underscore)
+        # Todo, not sure
+        check_unmodified_since(service.updated_at)
         attrs = service_attributes(service).inject({}) do |hash, key|
           hash.merge!(key => nil)

lib/api/snippets.rb

@@ -122,6 +122,7 @@ def public_snippets
         return not_found!('Snippet') unless snippet
         authorize! :destroy_personal_snippet, snippet
+        check_unmodified_since(snippet.updated_at)
         status 204
         snippet.destroy

lib/api/system_hooks.rb

@@ -66,6 +66,8 @@ class SystemHooks < Grape::API
         hook = SystemHook.find_by(id: params[:id])
         not_found!('System hook') unless hook
+        check_unmodified_since(hook.updated_at)
+
         status 204
         hook.destroy
       end