test: that a change to the discarded_at is staged as a difference

Jira-Issue: MAV-1346

Author: MartinVanIJcken

spec/models/immunisation_import_row_spec.rb

@@ -925,12 +925,13 @@
       end
     end
 
-    context "with an existing vaccination record" do
+    context "with an existing, discarded vaccination record" do
       let!(:existing_vaccination_record) do
         create(
           :vaccination_record,
           programme: programmes.first,
-          session: create(:session, team:, programmes:)
+          session: create(:session, team:, programmes:),
+          discarded_at: Time.current
         )
       end
 
@@ -940,6 +941,10 @@
 
       it { should_not be_nil }
       it { should eq(existing_vaccination_record) }
+
+      it "stages changes discarded at to nil" do
+        expect(vaccination_record.pending_changes["discarded_at"]).to be_nil
+      end
     end
 
     describe "#batch" do