return schemes with no location when searching

app/models/scheme.rb

@@ -6,7 +6,7 @@ class Scheme < ApplicationRecord
 
   scope :filter_by_id, ->(id) { where(id: (id.start_with?("S") ? id[1..] : id)) }
   scope :search_by_service_name, ->(name) { where("service_name ILIKE ?", "%#{name}%") }
-  scope :search_by_postcode, ->(postcode) { joins(:locations).where("locations.postcode ILIKE ?", "%#{postcode.delete(' ')}%") }
+  scope :search_by_postcode, ->(postcode) { joins("LEFT JOIN locations ON locations.scheme_id = schemes.id").where("locations.postcode ILIKE ?", "%#{postcode.delete(' ')}%") }
   scope :search_by, ->(param) { search_by_postcode(param).or(search_by_service_name(param)).or(filter_by_id(param)).distinct }
 
   validate :validate_confirmed

spec/features/schemes_spec.rb

@@ -119,6 +119,13 @@ RSpec.describe "Schemes scheme Features" do
         expect(page).to have_content(scheme_to_search.id_to_display)
       end
 
+      it "returns results with no location" do
+        scheme_to_search.locations.each { |location| location.destroy }
+        scheme_to_search.reload
+        click_button("Search")
+        expect(page).to have_content(scheme_to_search.id_to_display)
+      end
+
       it "allows clearing the search results" do
         fill_in("search", with: scheme_to_search.id_to_display)
         click_button("Search")

spec/requests/schemes_controller_spec.rb

@@ -179,6 +179,16 @@ RSpec.describe SchemesController, type: :request do
           end
         end
 
+        it "returns results with no location" do
+          searched_scheme.locations.each { |location| location.destroy }
+          searched_scheme.reload
+          get "/schemes?search=#{search_param}"
+          expect(page).to have_content(searched_scheme.id_to_display)
+          schemes.each do |scheme|
+            expect(page).not_to have_content(scheme.id_to_display)
+          end
+        end
+
         it "updates the table caption" do
           expect(page).to have_content("1 scheme found matching ‘#{search_param}’")
         end