Validate Role#name

app/models/role.rb

@@ -1,11 +1,17 @@
 # frozen_string_literal: true
 
 class Role < ApplicationRecord
+  NAMES = %w[
+    superuser
+  ].map(&:freeze).freeze
+
   has_and_belongs_to_many :accounts, join_table: :account_roles
 
   belongs_to :resource, polymorphic: true, optional: true
 
-  validates :name, presence: true
+  validates :name,
+            presence:  true,
+            inclusion: { in: NAMES }
 
   validates :resource_type,
             allow_nil: true,

spec/models/role_spec.rb

@@ -5,7 +5,17 @@ require 'rails_helper'
 RSpec.describe Role do
   subject { create :role }
 
-  it { is_expected.to validate_presence_of :name }
+  describe '#name' do
+    def allow_value(*)
+      super.for :name
+    end
+
+    it { is_expected.to validate_presence_of :name }
+
+    it { is_expected.not_to allow_value 'foobar' }
+
+    it { is_expected.to allow_value 'superuser' }
+  end
 
   pending "add some examples to (or delete) #{__FILE__}"
 end