Stop calculating work history after award/decline

When an application is awarded or declined, and the work history is
marked as ongoing, we stop counting the number of months when the
application is awarded or declined to ensure the number doesn't keep
increasing.

app/lib/work_history_duration.rb

@@ -102,7 +102,8 @@ def work_history_start_date(work_history)
   end
 
   def work_history_end_date(work_history)
-    work_history.end_date || Time.zone.today
+    work_history.end_date || application_form.awarded_at ||
+      application_form.declined_at || Time.zone.today
   end
 
   def date_first_of_month(date)

spec/lib/work_history_duration_spec.rb

@@ -76,6 +76,40 @@
       it { is_expected.to eq(7) }
     end
 
+    context "with an ongoing full time work history and an awarded application form" do
+      let(:application_form) do
+        create(:application_form, awarded_at: Date.new(2020, 12, 1))
+      end
+
+      before do
+        create(
+          :work_history,
+          application_form:,
+          start_date: Date.new(2020, 1, 1),
+          hours_per_week: 30,
+        )
+      end
+
+      it { is_expected.to eq(6) }
+    end
+
+    context "with an ongoing full time work history and a declined application form" do
+      let(:application_form) do
+        create(:application_form, declined_at: Date.new(2020, 12, 1))
+      end
+
+      before do
+        create(
+          :work_history,
+          application_form:,
+          start_date: Date.new(2020, 1, 1),
+          hours_per_week: 30,
+        )
+      end
+
+      it { is_expected.to eq(6) }
+    end
+
     context "with an ongoing part time work history" do
       before do
         create(