Normalise whitespace in NHS number (#3560)

When editing the NHS number of a patient we should normalise the
whitespace on the NHS number to ensure that it's accepted and is valid.
We do this already for spaces, but not for special unicode whitespace
characters.

Author: thomasleese

app/models/patient.rb

@@ -186,7 +186,10 @@ class Patient < ApplicationRecord
 
   encrypts :address_line_1, :address_line_2, :address_town
 
-  normalizes :nhs_number, with: -> { _1.blank? ? nil : _1.gsub(/\s/, "") }
+  normalizes :nhs_number,
+             with: -> do
+               it.blank? ? nil : it.normalise_whitespace.gsub(/\s/, "")
+             end
 
   before_destroy :destroy_childless_parents
 

spec/models/patient_spec.rb

@@ -157,6 +157,20 @@
     end
   end
 
+  describe "normalizations" do
+    let(:patient) { described_class.new }
+
+    it do
+      expect(patient).to normalize(:nhs_number).from(
+        "012\u200D345\u200D6789"
+      ).to("0123456789")
+    end
+
+    it { should normalize(:nhs_number).from(" 0123456789 ").to("0123456789") }
+
+    it { should normalize(:address_postcode).from(" SW111AA ").to("SW11 1AA") }
+  end
+
   describe "#vaccination_records" do
     subject(:vaccination_records) { patient.vaccination_records }
 
@@ -173,9 +187,6 @@
     it { should_not include(discarded_vaccination_record) }
   end
 
-  it { should normalize(:nhs_number).from(" 0123456789 ").to("0123456789") }
-  it { should normalize(:address_postcode).from(" SW111AA ").to("SW11 1AA") }
-
   describe "#match_existing" do
     subject(:match_existing) do
       described_class.match_existing(