Add a comma to the time system notes estimates

app/services/system_note_service.rb

@@ -159,7 +159,7 @@ module SystemNoteService
     body = if noteable.time_estimate == 0
              "removed time estimate"
            else
-             "changed time estimate to #{parsed_time}"
+             "changed time estimate to #{parsed_time},"
            end
 
     create_note(NoteSummary.new(noteable, project, author, body, action: 'time_tracking'))

changelogs/unreleased/40402-time-estimate-system-notes-can-be-confusing.yml

+---
+title: Add a comma to the time estimate system notes
+merge_request: 18326
+author:
+type: changed

spec/services/system_note_service_spec.rb

@@ -909,7 +909,13 @@ describe SystemNoteService do
       it 'sets the note text' do
         noteable.update_attribute(:time_estimate, 277200)
 
-        expect(subject.note).to eq "changed time estimate to 1w 4d 5h"
+        expect(subject.note).to eq "changed time estimate to 1w 4d 5h,"
+      end
+
+      it 'appends a comma to separate the note from the update_at time' do
+        noteable.update_attribute(:time_estimate, 277200)
+
+        expect(subject.note).to end_with(',')
       end
     end