```ruby
FactoryGirl.define do
  factory :user do
    user_name { Faker::Internet.user_name }
    first_name { Faker::Name.first_name }
    last_name { Faker::Name.last_name }
  end
end
```

Fix flaky user name uniqueness in specs
user
```ruby
FactoryGirl.define do
  factory :user do
    sequence(:user_name) { |n| Faker::Internet.user_name + n.to_s }
    first_name { Faker::Name.first_name }
    last_name { Faker::Name.last_name }
  end
end
```
assistant