Default to location code if LocalAuthority is not found by location code

app/models/lettings_log.rb

@@ -84,7 +84,7 @@ class LettingsLog < Log
 
   def la
     if location
-      location.linked_local_authorities.active(form.start_date).first&.code
+      location.linked_local_authorities.active(form.start_date).first&.code || location.location_code
     else
       super
     end

app/models/location.rb

@@ -132,7 +132,7 @@ class Location < ApplicationRecord
 
   def linked_local_authorities
     la = LocalAuthority.find_by(code: location_code)
-    return [] unless la
+    return LocalAuthority.none unless la
 
     LocalAuthority.where(id: [la.id] + la.linked_local_authority_ids)
   end

spec/models/lettings_log_spec.rb

@@ -2033,6 +2033,19 @@ RSpec.describe LettingsLog do
             end
           end
         end
+
+        context "and the location no local authorities associated with the location_code" do
+          before do
+            location.update!(location_code: "E01231231")
+            lettings_log.update!(location:)
+          end
+
+          it "returns the correct la" do
+            expect(location.location_code).to eq("E01231231")
+            expect(lettings_log["location_id"]).to eq(location.id)
+            expect(lettings_log.la).to eq("E01231231")
+          end
+        end
       end
 
       context "and not renewal" do

spec/models/location_spec.rb

@@ -32,6 +32,19 @@ RSpec.describe Location, type: :model do
       expect(location.linked_local_authorities.active(Time.zone.local(2022, 4, 1)).first.code).to eq("E07000030")
       expect(location.linked_local_authorities.active(Time.zone.local(2023, 4, 1)).first.code).to eq("E06000063")
     end
+
+    context "when location_code is no in LocalAuthorities table" do
+      before do
+        stub_request(:get, /api.postcodes.io\/postcodes\/CA101AA/)
+          .to_return(status: 200, body: '{"status":200,"result":{"admin_district":"Eden","codes":{"admin_district":"E01231231"}}}', headers: {})
+      end
+
+      it "defaults for location code for la" do
+        location.update!(postcode: "CA10 1AA")
+        expect(location.linked_local_authorities.count).to eq(0)
+        expect(location.location_code).to eq("E01231231")
+      end
+    end
   end
 
   describe "#postcode" do