From https://once.com/writebook

test/models/user/role_test.rb

@@ -0,0 +1,14 @@
+require "test_helper"
+
+class User::RoleTest < ActiveSupport::TestCase
+  test "creating users makes them members by default" do
+    assert User.create!(name: "User", email_address: "user@example.com", password: "secret123456").member?
+  end
+
+  test "can_administer?" do
+    assert User.new(role: :administrator).can_administer?
+
+    assert_not User.new(role: :member).can_administer?
+    assert_not User.new.can_administer?
+  end
+end