Fix wording on milestone due date today

Fix wording on milestone due date, to show today instead of
hours ago or remaining, when milestone is due today.

app/serializers/entity_date_helper.rb

@@ -46,12 +46,14 @@ module EntityDateHelper
   # If start date is provided and elapsed, with no due date, it returns "# days elapsed"
   def remaining_days_in_words(due_date, start_date = nil)
     if due_date&.past?
-      content_tag(:strong, 'Past due')
+      content_tag(:strong, _('Past due'))
+    elsif due_date&.today?
+      content_tag(:strong, _('Today'))
     elsif start_date&.future?
-      content_tag(:strong, 'Upcoming')
+      content_tag(:strong, _('Upcoming'))
     elsif due_date
       is_upcoming = (due_date - Date.today).to_i > 0
-      time_ago = time_ago_in_words(due_date)
+      time_ago = distance_of_time_in_words(due_date, Date.today)
       # https://gitlab.com/gitlab-org/gitlab-ce/issues/49440
       #
@@ -59,8 +61,8 @@ module EntityDateHelper
       # of the string instead of piecewise translations.
       content = time_ago
         .gsub(/\d+/) { |match| "<strong>#{match}</strong>" }
-        .remove("about ")
-      remaining_or_ago = is_upcoming ? _("remaining") : _("ago")
+        .remove('about ')
+      remaining_or_ago = is_upcoming ? _('remaining') : _('ago')
       "#{content} #{remaining_or_ago}".html_safe
     elsif start_date&.past?

changelogs/unreleased/62591-fix-milestone-due-date-today-wording.yml

+---
+title: Fix wording on milestone due date when milestone is due today
+merge_request: 32096
+author:
+type: changed

spec/serializers/entity_date_helper_spec.rb

@@ -57,6 +57,28 @@ describe EntityDateHelper do
       end
     end
+    context 'when milestone due date is today' do
+      let(:milestone_remaining) { date_helper_class.remaining_days_in_words(Date.today) }
+
+      it 'returns today' do
+        expect(milestone_remaining).to eq("<strong>Today</strong>")
+      end
+    end
+
+    context 'when milestone due date is tomorrow' do
+      let(:milestone_remaining) { date_helper_class.remaining_days_in_words(Date.tomorrow) }
+
+      it 'returns 1 day remaining' do
+        expect(milestone_remaining).to eq("<strong>1</strong> day remaining")
+      end
+
+      it 'returns 1 day remaining when queried mid-day' do
+        Timecop.freeze(Time.utc(2017, 3, 17, 13, 10)) do
+          expect(milestone_remaining).to eq("<strong>1</strong> day remaining")
+        end
+      end
+    end
+
     context 'when less than 1 year and more than 30 days remaining' do
       let(:milestone_remaining) { date_helper_class.remaining_days_in_words(2.months.from_now.utc.to_date) }