fix(customer): Add missing validation for shipping country (#2804)

## Context

Validation for valid country code was missing which allows to set
invalid value via API

## Description

Added missing validation and tests

app/models/customer.rb

@@ -68,7 +68,7 @@ class Customer < ApplicationRecord
   sequenced scope: ->(customer) { customer.organization.customers.with_discarded },
     lock_key: ->(customer) { customer.organization_id }
 
-  validates :country, country_code: true, unless: -> { country.nil? }
+  validates :country, :shipping_country, country_code: true, allow_nil: true
   validates :document_locale, language_code: true, unless: -> { document_locale.nil? }
   validates :currency, inclusion: {in: currency_list}, allow_nil: true
   validates :external_id,

spec/models/customer_spec.rb

@@ -31,19 +31,6 @@
 
     let(:external_id) { SecureRandom.uuid }
 
-    it 'validates the country' do
-      expect(customer).to be_valid
-
-      customer.country = 'fr'
-      expect(customer).to be_valid
-
-      customer.country = 'foo'
-      expect(customer).not_to be_valid
-
-      customer.country = ''
-      expect(customer).not_to be_valid
-    end
-
     it 'validates the language code' do
       customer.document_locale = nil
       expect(customer).to be_valid
@@ -70,6 +57,72 @@
       customer.timezone = 'America/Guadeloupe'
       expect(customer).not_to be_valid
     end
+
+    describe 'of country' do
+      let(:customer) { build_stubbed(:customer, country:) }
+      let(:error) { customer.errors.where(:country, :country_code_invalid) }
+
+      before { customer.valid? }
+
+      context 'with non-null country value' do
+        context 'when value is a valid country code' do
+          let(:country) { TZInfo::Country.all_codes.sample }
+
+          it 'does not add an error' do
+            expect(error).not_to be_present
+          end
+        end
+
+        context 'when value is an invalid country code' do
+          let(:country) { 'USA' }
+
+          it 'adds an error' do
+            expect(error).to be_present
+          end
+        end
+      end
+
+      context 'with null country value' do
+        let(:country) { nil }
+
+        it 'does not add an error' do
+          expect(error).not_to be_present
+        end
+      end
+    end
+
+    describe 'of shipping country' do
+      let(:customer) { build_stubbed(:customer, shipping_country:) }
+      let(:error) { customer.errors.where(:shipping_country, :country_code_invalid) }
+
+      before { customer.valid? }
+
+      context 'with non-null shipping country value' do
+        context 'when value is a valid country code' do
+          let(:shipping_country) { TZInfo::Country.all_codes.sample }
+
+          it 'does not add an error' do
+            expect(error).not_to be_present
+          end
+        end
+
+        context 'when value is an invalid country code' do
+          let(:shipping_country) { 'USA' }
+
+          it 'adds an error' do
+            expect(error).to be_present
+          end
+        end
+      end
+
+      context 'with null shipping country value' do
+        let(:shipping_country) { nil }
+
+        it 'does not add an error' do
+          expect(error).not_to be_present
+        end
+      end
+    end
   end
 
   describe '#display_name' do

spec/services/customer_portal/customer_update_service_spec.rb

@@ -29,7 +29,7 @@
         zipcode: "Updated customer shipping zipcode",
         city: "Updated customer shipping city",
         state: "Updated customer shipping state",
-        country: "Updated customer shipping country"
+        country: "PT"
       }
     }
   end