Show service areas on guest show partner page

app/helpers/partners_helper.rb

@@ -7,4 +7,19 @@ def options_for_service_area_neighbourhoods
     @all_neighbourhoods.filter { |e| e.name != '' }
                        .collect { |e| { name: e.contextual_name, id: e.id } }
   end
+
+  def partner_service_area_text(partner)
+    neighbourhoods = partner.service_area_neighbourhoods.order(:name).all
+
+    if neighbourhoods.length == 1
+      neighbourhoods.first.name
+
+    else
+      head = neighbourhoods[0..-2]
+      tail = neighbourhoods[-1]
+
+      "#{head.map(&:name).join(', ')} and #{tail.name}"
+    end
+  end
+
 end

app/models/partner.rb

@@ -147,6 +147,10 @@ def should_generate_new_friendly_id?
     slug.blank?
   end
 
+  def has_service_areas?
+    service_areas.count > 0
+  end
+
   def permalink
     "https://placecal.org/partners/#{id}"
   end

app/views/partners/show.html.erb

@@ -38,6 +38,9 @@
         %>
 
         <h3 class="udl udl--fw allcaps h4">Address</h3>
+        <% if @partner.has_service_areas? %>
+          <p>We operate in <%= partner_service_area_text(@partner) %>.</p>
+        <% end %>
         <%= render_component "address",
           address: @partner.address
         %>

test/helpers/partners_helper_test.rb

@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+require 'test_helper'
+
+class PartnersHelperTest < ActionView::TestCase
+  setup do
+    @partner = FactoryBot.create(:partner)
+    @hoods = [
+      FactoryBot.create(:neighbourhood, name: 'alpha'),
+      FactoryBot.create(:neighbourhood, name: 'beta'),
+      FactoryBot.create(:neighbourhood, name: 'cappa')
+    ]
+  end
+
+  # testing partner_service_area_text
+
+  test "shows only one text correctly" do
+    @partner.service_areas.create neighbourhood: @hoods[0]
+
+    output = partner_service_area_text(@partner)
+
+    assert output == 'alpha'
+  end
+
+  test "shows two texts correctly" do
+    @partner.service_areas.create neighbourhood: @hoods[0]
+    @partner.service_areas.create neighbourhood: @hoods[1]
+
+    output = partner_service_area_text(@partner)
+
+    assert output == 'alpha and beta'
+  end
+
+  test "shows N texts correctly" do
+    @partner.service_areas.create neighbourhood: @hoods[0]
+    @partner.service_areas.create neighbourhood: @hoods[1]
+    @partner.service_areas.create neighbourhood: @hoods[2]
+
+    output = partner_service_area_text(@partner)
+
+    assert output == 'alpha, beta and cappa'
+  end
+end