MissingDependentDestroyChecker

This checker identifies cases where a belongs_to association is backed by a foreign key without an on_delete option. While the foreign key enforces data integrity by preventing orphaned records, attempting to delete the parent object will raise an error due to the database constraint.

To avoid such errors and handle deletions gracefully, you should either:

• Add a dependent: :destroy, :delete, :delete_all, or :nullify option to the corresponding has_one or has_many association.
• Set the foreign key's on_delete option to cascade or nullify.

Use case example:

class User
  has_many :posts
end

class Post
  belongs_to :user 
end

# schema.rb
add_foreign_key "posts", "users"