Handle the case when NHS number is nil

If a patient's NHS number is `nil`, then there needs to be no API vaccination records associated with them. Previously they would've been left, but now they're removed.

Author: alistair-white-horne-tng

app/jobs/search_vaccination_records_in_nhs_job.rb

@@ -14,28 +14,32 @@ def perform(patient)
       Sentry.set_tags(tx_id:, job_id: provider_job_id || job_id)
 
       return unless Flipper.enabled?(:imms_api_search_job)
-      return if patient.nhs_number.nil?
 
       programmes = Programme.can_search_in_immunisations_api
 
-      fhir_bundle =
-        NHS::ImmunisationsAPI.search_immunisations(patient, programmes:)
+      if patient.nhs_number.nil?
+        incoming_vaccination_records = []
+      else
+        fhir_bundle =
+          NHS::ImmunisationsAPI.search_immunisations(patient, programmes:)
 
-      incoming_vaccination_records =
-        extract_vaccination_records(fhir_bundle).map do |fhir_record|
-          if FHIRMapper::VaccinationRecord::MAVIS_SYSTEM_NAME.in?(
-               fhir_record.identifier.map(&:system)
-             )
-            next
+        incoming_vaccination_records =
+          extract_vaccination_records(fhir_bundle).map do |fhir_record|
+            if FHIRMapper::VaccinationRecord::MAVIS_SYSTEM_NAME.in?(
+                 fhir_record.identifier.map(&:system)
+               )
+              next
+            end
+
+            FHIRMapper::VaccinationRecord.from_fhir_record(
+              fhir_record,
+              patient:,
+              team: patient.school.team
+            )
           end
+        incoming_vaccination_records = incoming_vaccination_records.compact
+      end
 
-          FHIRMapper::VaccinationRecord.from_fhir_record(
-            fhir_record,
-            patient:,
-            team: patient.school.team
-          )
-        end
-      incoming_vaccination_records = incoming_vaccination_records.compact
       existing_vaccination_records =
         patient
           .vaccination_records

spec/jobs/search_vaccination_records_in_nhs_job_spec.rb

@@ -5,7 +5,8 @@
 
   let(:team) { create(:team) }
   let(:school) { create(:school, team:) }
-  let(:patient) { create(:patient, team:, school:, nhs_number: "9449308357") }
+  let(:patient) { create(:patient, team:, school:, nhs_number:) }
+  let(:nhs_number) { "9449308357" }
   let!(:programme) { create(:programme, :flu) }
 
   before do
@@ -163,5 +164,22 @@
         )
       end
     end
+
+    context "with no NHS number" do
+      let(:nhs_number) { nil }
+
+      let(:existing_bundle) do
+        FHIR.from_contents(
+          file_fixture("fhir/search_response_2_results.json").read
+        )
+      end
+
+      it "deletes all the API records and does not create any new ones" do
+        expect { perform_job }.to change {
+          patient.vaccination_records.count
+        }.by(-2)
+        expect(patient.vaccination_records.count).to eq(0)
+      end
+    end
   end
 end