Scope changesets to processed when keeping both records in import duplicates

When resolving import duplicate issues by keeping both records (creating
a new patient from pending changes), only reassigned the latests processed
changeset to the new record. This prevents changesets that are still being
reviewed from being incorrectly reassigned.

Previously, the code selected the most recent changeset without checking
its status. If another CSV import was uploaded for the same patient while
the duplicate resolution was in progress, the unprocessed changeset from
the new import would be incorrectly reassigned to the newly created
patient (instead of staying with the original patient record).

Author: murugapl

app/forms/import_duplicate_form.rb

@@ -66,10 +66,29 @@ def discard_pending_changes!
   end
 
   def keep_both_changes!
-    if can_keep_both? && can_apply?
-      changeset = object.changesets.includes(:import).order(:created_at).last
-      object.apply_pending_changes_to_new_record!(changeset:)
-    end
+    return unless can_keep_both?
+    return unless can_apply?
+
+    object.apply_pending_changes_to_new_record!(
+      changeset: changeset_for_keep_both
+    )
+  end
+
+  def changeset_for_keep_both
+    scope = object.changesets.includes(:import).order(:created_at)
+
+    return scope.last unless Flipper.enabled?(:import_review_screen)
+
+    completed_import_statuses = %w[
+      processed
+      partially_processed
+      removing_parent_relationships
+    ]
+
+    scope
+      .processed
+      .select { completed_import_statuses.include?(it.import&.status) }
+      .last
   end
 
   def reset_count!

spec/forms/import_duplicate_form_spec.rb

@@ -55,13 +55,21 @@
             :class_import,
             :import_issue,
             import: class_import,
-            patient: existing_patient
+            patient: existing_patient,
+            status: :processed
           )
         end
 
         before do
           existing_patient.update!(pending_changes: { "given_name" => "Twin" })
           class_import.parent_relationships << import_relationship
+          class_import.update!(
+            status: :processed,
+            processed_at: Time.current,
+            new_record_count: 0,
+            changed_record_count: 0,
+            exact_duplicate_record_count: 0
+          )
         end
 
         it "moves imported parent relationships to the new patient when keeping both" do
@@ -203,4 +211,68 @@
       end
     end
   end
+
+  describe "#changeset_for_keep_both" do
+    subject(:selected_changeset) { form.send(:changeset_for_keep_both) }
+
+    let(:team) { create(:team, programmes: [programme]) }
+    let(:session) { create(:session, team:, programmes: [programme]) }
+    let(:existing_patient) { create(:patient) }
+
+    let(:form) do
+      described_class.new(
+        apply_changes: "keep_both",
+        object: existing_patient,
+        current_team: team
+      )
+    end
+
+    let(:completed_import) { create(:class_import, :processed, session:) }
+
+    let(:incomplete_import) do
+      create(:class_import, session:, status: :in_review)
+    end
+
+    let!(:eligible_old) do
+      create(
+        :patient_changeset,
+        :class_import,
+        :import_issue,
+        import: completed_import,
+        patient: existing_patient,
+        status: :processed,
+        matched_on_nhs_number: false,
+        created_at: 3.minutes.ago
+      )
+    end
+
+    let!(:newest_processed_but_incomplete_import) do
+      create(
+        :patient_changeset,
+        :class_import,
+        :import_issue,
+        import: incomplete_import,
+        patient: existing_patient,
+        status: :processed,
+        matched_on_nhs_number: false,
+        created_at: 1.minute.ago
+      )
+    end
+
+    context "when import_review_screen is enabled" do
+      before { Flipper.enable(:import_review_screen) }
+
+      it "returns the latest processed changeset from a completed import" do
+        expect(selected_changeset.id).to eq(eligible_old.id)
+      end
+    end
+
+    context "when import_review_screen is disabled" do
+      it "returns the latest changeset regardless of statuses" do
+        expect(selected_changeset.id).to eq(
+          newest_processed_but_incomplete_import.id
+        )
+      end
+    end
+  end
 end