Readded email uniqueness validation

app/models/user.rb

@@ -13,8 +13,7 @@ class User < ApplicationRecord
   validates :email,
             presence: { message: "Enter an email address" },
             uniqueness: { message: "Email address must be unique" },
-            notify_email: true,
-            on: :npq_separation
+            notify_email: true
   # rubocop:enable Rails/UniqueValidationWithoutIndex
 
   validates :uid, uniqueness: { allow_blank: true }

spec/lib/services/get_an_identity_service/webhooks/user_updated_processor_spec.rb

@@ -60,6 +60,26 @@
       })
     end
 
+    context "when the new email is already in use" do
+      before do
+        create(:user, email: new_email)
+      end
+
+      it "marks the webhook_message as failed" do
+        expect {
+          described_class.call(webhook_message:)
+        }.to change {
+          webhook_message.reload.slice(:status, :status_comment)
+        }.from(
+          "status" => "pending",
+          "status_comment" => nil,
+        ).to({
+          "status" => "failed",
+          "status_comment" => "Email Email address must be unique",
+        })
+      end
+    end
+
     context "when the trn is not present" do
       let(:new_trn) { nil }
       let(:new_trn_status) { "not_found" }

spec/models/user_spec.rb

@@ -13,7 +13,7 @@
   describe "validations" do
     it { is_expected.to validate_presence_of(:full_name).with_message("Enter a full name") }
     it { is_expected.to validate_presence_of(:email).on(:npq_separation).with_message("Enter an email address") }
-    it { is_expected.to validate_uniqueness_of(:email).on(:npq_separation).case_insensitive.with_message("Email address must be unique") }
+    it { is_expected.to validate_uniqueness_of(:email).case_insensitive.with_message("Email address must be unique") }
     it { is_expected.not_to allow_value("invalid-email").for(:email).on(:npq_separation) }
     it { is_expected.to validate_uniqueness_of(:uid).allow_blank }