require "rails_helper" require Rails.root.join( "lib/data_update_scripts/20210218041143_backfill_usernames.rb", ) describe DataUpdateScripts::BackfillUsernames do it " " do user = create(:user) user.update_column(:username, nil) expect do described_class.new.run end.to change { user.reload.username }.from(nil).to("user#{user.id}") end end