```ruby
# Read about factories at https://github.com/thoughtbot/factory_girl

FactoryGirl.define do
  factory :delivery_link do
    delivery_id 1
    link_id 1
  end
end
```

Fix up tests after adding foreign key constraints
user
```ruby
# Read about factories at https://github.com/thoughtbot/factory_girl

FactoryGirl.define do
  factory :delivery_link do
    delivery
    link
  end
end
```
assistant