Do not allow spaces in external billing

app/models/enterprise.rb

@@ -127,6 +127,9 @@
               message: Spree.t('errors.messages.invalid_instagram_url')
             }, allow_blank: true
   validate :validate_white_label_logo_link
+  validates :external_billing_id,
+            format: { with: /^\S+$/ },
+            allow_blank: true
 
   before_validation :initialize_permalink, if: lambda { permalink.nil? }
   before_validation :set_unused_address_fields

spec/models/enterprise_spec.rb

@@ -415,6 +415,13 @@
         expect(e).not_to be_valid
       end
     end
+
+    describe "external_billing_id" do
+      it "does not validate the external_billing_id attribute with a space" do
+        e = build(:enterprise, external_billing_id: 'with spaces')
+        expect(e).not_to be_valid
+      end
+    end
   end
 
   describe "serialisation" do