Add success banner for new users (#2827)

app/controllers/users_controller.rb

@@ -114,6 +114,7 @@ class UsersController < ApplicationController
 
     validate_attributes
     if @user.errors.empty? && @user.save
+      flash[:notice] = "Invitation sent to #{@user.email}"
       redirect_to created_user_redirect_path
     else
       unless @user.errors[:organisation].empty?

spec/requests/users_controller_spec.rb

@@ -1043,6 +1043,9 @@ RSpec.describe UsersController, type: :request do
 
       it "invites a new user" do
         expect { request }.to change(User, :count).by(1)
+        follow_redirect!
+        expect(page).to have_css(".govuk-notification-banner.govuk-notification-banner--success")
+        expect(page).to have_content("Invitation sent to new_user@example.com")
       end
 
       it "sends an invitation email" do