Anonymous Collection Proxies

Today I learned you can pass a block to relationships like has_many, which lets you extend the collection proxy anonymously with new methods.

class Account < ActiveRecord::Base
  has_many :people do
    def find_or_create_by_name(name)
      first_name, last_name = name.split(" ")
      find_or_create_by(first_name:, last_name:)
    end
  end
end

person = Account
  .first
  .people
  .find_or_create_by_name("Landon Schropp")

person.first_name # => "Landon"
person.last_name  # => "Schropp"

This is not documented in the Active Record Associations guide, but it is in the ActiveRecord::Assocations::ClassMethods documentation.