CLDC-4515: update lettings log spec and use persisted? for cleanliness

app/models/derived_variables/lettings_log_variables.rb

@@ -176,7 +176,7 @@ module DerivedVariables::LettingsLogVariables
 
     if !form.start_year_2026_or_later? && is_supported_housing?
       reset_address_fields!
-    elsif form.start_year_2026_or_later? && location_changed? && location_id_was.present?
+    elsif form.start_year_2026_or_later? && location_changed? && persisted?
       reset_address_fields!
       self.la = nil
     end

spec/models/lettings_log_spec.rb

@@ -1965,8 +1965,8 @@ RSpec.describe LettingsLog do
       context "when there is a duplicate supported housing log" do
         let(:scheme) { create(:scheme, owning_organisation: organisation) }
         let(:location) { create(:location, scheme:) }
-        let!(:supported_housing_log) { create(:lettings_log, :duplicate, needstype: 2, location:, scheme:, owning_organisation: organisation) }
-        let!(:duplicate_supported_housing_log) { create(:lettings_log, :duplicate, needstype: 2, location:, scheme:, owning_organisation: organisation) }
+        let!(:supported_housing_log) { create(:lettings_log, :duplicate, needstype: 2, location:, scheme:, owning_organisation: organisation, postcode_full: nil) }
+        let!(:duplicate_supported_housing_log) { create(:lettings_log, :duplicate, needstype: 2, location:, scheme:, owning_organisation: organisation, postcode_full: nil) }
 
         it "returns the log as a duplicate" do
           expect(duplicate_sets).to contain_exactly(

spec/requests/lettings_logs_controller_spec.rb

@@ -1252,7 +1252,7 @@ RSpec.describe LettingsLogsController, type: :request do
 
             before do
               create_list(:lettings_log, further_unresolved_logs_count, unresolved: true, assigned_to: user)
-              lettings_log.update!(needstype: 2, scheme:, location:, postcode_full: nil)
+              lettings_log.update!(needstype: 2, scheme:, location:)
               get lettings_log_path(lettings_log)
             end