feat: add tests for relationship import

app/services/imports/lettings_logs_field_import_service.rb

@@ -123,8 +123,6 @@ module Imports
         tenant_code = string_or_nil(xml_doc, "_2bTenCode")
         if tenant_code.present? && record.tenancycode.blank?
           record.update!(tenancycode: tenant_code)
-        else
-          # Continue
         end
       else
         @logger.warn("Could not find record matching legacy ID #{old_id}")

app/services/imports/organisation_relationship_import_service.rb

@@ -1,7 +1,7 @@
 module Imports
   class OrganisationRelationshipImportService < ImportService
     def create_organisation_relationships(folder)
-      import_from(folder, :create_organisation_relationships)
+      import_from(folder, :create_organisation_relationship)
     end
 
   private
@@ -14,5 +14,18 @@ module Imports
 
       OrganisationRelationship.find_or_create_by!(parent_organisation_id:, child_organisation_id:)
     end
+
+    def find_organisation_id(xml_doc, id_field)
+      old_visible_id = string_or_nil(xml_doc, id_field)
+      organisation = Organisation.find_by(old_visible_id:)
+      raise "Organisation not found with legacy ID #{old_visible_id}" if organisation.nil?
+
+      organisation.id
+    end
+
+    def string_or_nil(xml_doc, attribute)
+      str = field_value(xml_doc, "institution-link", attribute)
+      str.presence
+    end
   end
 end

app/services/imports/scheme_import_service.rb

@@ -14,8 +14,6 @@ module Imports
           old_id: attributes["old_id"],
           old_visible_id: attributes["old_visible_id"],
         )
-      else
-        # Continue
       end
     rescue ActiveRecord::RecordInvalid
       @logger.error("Scheme #{attributes['old_visible_id']}: Failed to import")

spec/fixtures/imports/institution-link/test_institution_link.xml

@@ -0,0 +1,5 @@
+<institution-link:institution-link xmlns:institution-link="dclg:institution-link">
+  <institution-link:id>1</institution-link:id>
+  <institution-link:parent-institution>1</institution-link:parent-institution>
+  <institution-link:child-institution>2</institution-link:child-institution>
+</institution-link:institution-link>

spec/services/imports/organisation_relationship_import_service_spec.rb

@@ -0,0 +1,60 @@
+require "rails_helper"
+
+RSpec.describe Imports::OrganisationRelationshipImportService do
+  let(:storage_service) { instance_double(Storage::S3Service) }
+  let(:logger) { instance_double(Rails::Rack::Logger) }
+  let(:folder_name) { "organisation_relationships" }
+  let(:filenames) { %w[my_folder/my_file1.xml my_folder/my_file2.xml] }
+  let(:fixture_directory) { "spec/fixtures/imports/institution-link" }
+  let!(:child_organisation) { create(:organisation, old_visible_id: 1) }
+  let!(:parent_organisation) { create(:organisation, old_visible_id: 2) }
+  let!(:grandparent_organisation) { create(:organisation, old_visible_id: 3) }
+
+  def create_organisation_relationship_file(fixture_directory, child_organisation_id, parent_organisation_id)
+    file = File.open("#{fixture_directory}/test_institution_link.xml")
+    doc =  Nokogiri::XML(file)
+    doc.at_xpath("//institution-link:parent-institution").content = parent_organisation_id if parent_organisation_id
+    doc.at_xpath("//institution-link:child-institution").content = child_organisation_id if child_organisation_id
+    StringIO.new(doc.to_xml)
+  end
+
+  context "when importing organisation relationships" do
+    subject(:import_service) { described_class.new(storage_service) }
+
+    before do
+      allow(storage_service).to receive(:list_files)
+                                   .and_return(filenames)
+      allow(storage_service).to receive(:get_file_io)
+                                   .with(filenames[0])
+                                   .and_return(create_organisation_relationship_file(fixture_directory, 1, 2))
+      allow(storage_service).to receive(:get_file_io)
+                                   .with(filenames[1])
+                                   .and_return(create_organisation_relationship_file(fixture_directory, 2, 3))
+    end
+
+    it "successfully create an organisation relationship with the expected data" do
+      import_service.create_organisation_relationships(folder_name)
+
+      organisation_relationship = OrganisationRelationship.find { |r| r.child_organisation == child_organisation }
+      expect(organisation_relationship.child_organisation).to eq(child_organisation)
+      expect(organisation_relationship.parent_organisation).to eq(parent_organisation)
+    end
+
+    it "doesn't re-import duplicates" do
+      import_service.create_organisation_relationships(folder_name)
+      import_service.create_organisation_relationships(folder_name)
+
+      expect(OrganisationRelationship.count).to eq(2)
+    end
+
+    it "successfully creates multiple organisation relationships" do
+      expect(storage_service).to receive(:list_files).with(folder_name)
+      expect(storage_service).to receive(:get_file_io).with(filenames[0]).ordered
+      expect(storage_service).to receive(:get_file_io).with(filenames[1]).ordered
+
+      expect { import_service.create_organisation_relationships(folder_name) }.to change(OrganisationRelationship, :count).by(2)
+      expect(OrganisationRelationship).to exist(child_organisation:, parent_organisation:)
+      expect(OrganisationRelationship).to exist(child_organisation: parent_organisation, parent_organisation: grandparent_organisation)
+    end
+  end
+end