Remove superfluous db query (with 1=0 clause)

Author: philippthun

lib/cloud_controller/diego/tasks_sync.rb

@@ -37,8 +37,10 @@ def sync
             end
           end
 
-          TaskModel.where(guid: tasks_to_fail).each do |cc_task|
-            cc_task.update(state: TaskModel::FAILED_STATE, failure_reason: BULKER_TASK_FAILURE)
+          unless tasks_to_fail.empty?
+            TaskModel.where(guid: tasks_to_fail).each do |cc_task|
+              cc_task.update(state: TaskModel::FAILED_STATE, failure_reason: BULKER_TASK_FAILURE)
+            end
           end
         end
 

spec/unit/lib/cloud_controller/diego/tasks_sync_spec.rb

@@ -37,6 +37,12 @@ module Diego
               subject.sync
             end.not_to(change { task.reload.state })
           end
+
+          it 'does not query tasks with a 1=0 clause' do
+            expect do
+              subject.sync
+            end.to have_queried_db_times(/select \* from .tasks. where \(1 = 0\)/i, 0)
+          end
         end
 
         context 'when a running CC task is missing from BBS' do