Use constant in markdown file and add test

app/views/content/accessibility_statement.md

@@ -32,11 +32,11 @@ If you need information on this website in a different format like accessible PD
 
 We’ll consider your request and get back to you in 2 working days.
 
-You can also [contact us through the helpdesk](https://mhclgdigital.atlassian.net/servicedesk/customer/portal/54).
+You can also [contact us through the helpdesk](<%= GlobalConstants::HELPDESK_URL %>).
 
 ### Reporting accessibility problems with this website
 
-We’re always looking to improve the accessibility of this website. If you find any problems not listed on this page or think we’re not meeting accessibility requirements, [contact the helpdesk](https://mhclgdigital.atlassian.net/servicedesk/customer/portal/54).
+We’re always looking to improve the accessibility of this website. If you find any problems not listed on this page or think we’re not meeting accessibility requirements, [contact the helpdesk](<%= GlobalConstants::HELPDESK_URL %>).
 
 ### Enforcement procedure
 

spec/requests/content_controller_spec.rb

@@ -31,6 +31,11 @@ RSpec.describe ContentController, type: :request do
       it "returns the page" do
         expect(page).to have_title("Accessibility statement")
       end
+
+      it "links to the helpdesk" do
+        expect(page).to have_link("contact us through the helpdesk", href: "https://mhclgdigital.atlassian.net/servicedesk/customer/portal/54")
+        expect(page).to have_link("contact the helpdesk", href: "https://mhclgdigital.atlassian.net/servicedesk/customer/portal/54")
+      end
     end
 
     describe "render data sharing agreement" do