Only display recent merges for absorbing org

app/models/organisation.rb

@@ -156,4 +156,8 @@ class Organisation < ApplicationRecord
 
     absorbed_organisations.absorbed_on(recent_merge_date)
   end
+
+  def has_absorbed_organisations_during_open_collection_period?
+    absorbed_organisations.any? && (recent_merge_date.blank? || recent_merge_date.present? && recent_merge_date > FormHandler.instance.start_date_of_earliest_open_for_editing_collection_period)
+  end
 end

app/views/organisations/_merged_organisation_details.html.erb

@@ -1,4 +1,4 @@
-<% if @organisation.absorbed_organisations.any? %>
+<% if @organisation.has_absorbed_organisations_during_open_collection_period? %>
   <%= govuk_details(summary_text: "View all organisations that were merged into #{@organisation.name}") do %>
     <p>Merge date: <%= @organisation.recent_merge_date&.to_formatted_s(:govuk_date) %></p>
     <%= govuk_table do |table| %>

spec/requests/organisations_controller_spec.rb

@@ -308,6 +308,24 @@ RSpec.describe OrganisationsController, type: :request do
             end
           end
 
+          context "when the organisation has absorbed other organisations during a closed collection period" do
+            let!(:absorbed_organisation) { create(:organisation, name: "First Absorbed Organisation") }
+            let!(:other_absorbed_organisation) { create(:organisation, name: "Other Absorbed Organisation") }
+
+            before do
+              absorbed_organisation.update!(merge_date: Time.zone.local(2021, 4, 3), absorbing_organisation: organisation)
+              other_absorbed_organisation.update!(merge_date: Time.zone.local(2021, 4, 3), absorbing_organisation: organisation)
+              get "/organisations/#{organisation.id}/details", headers:, params: {}
+            end
+
+            it "does not display absorbed organisations" do
+              expect(page).not_to have_content("View all organisations that were merged into #{organisation.name}")
+              expect(page).not_to have_content("Merge date: 3 April 2021")
+              expect(page).not_to have_content("First Absorbed Organisation")
+              expect(page).not_to have_content("Other Absorbed Organisation")
+            end
+          end
+
           context "when the organisation has absorbed other organisations without merge dates" do
             let!(:absorbed_organisation) { create(:organisation, name: "First Absorbed Organisation") }
             let!(:other_absorbed_organisation) { create(:organisation, name: "Other Absorbed Organisation") }