nested_attributes_test.rb

require "logger"
require "sequel"

DB = Sequel.connect ENV["DATABASE_URL"], test: true, encoding: "utf-8"
DB.logger = Logger.new($stdout)

Sequel.extension :migration

Sequel.migration do
  up do
    create_table :releases do
      primary_key :id
      column :title, :text
    end

    create_table :tracks do
      primary_key :id
      foreign_key :release_id, :releases, null: false
      column :title, :text
    end
  end
end.apply(DB, :up)

class Release < Sequel::Model
  plugin :nested_attributes
  one_to_many :tracks
  nested_attributes :tracks
end

class Track < Sequel::Model
  many_to_one :release

  def validate
    puts "Track validate #{associations[:release]&.object_id}"
  end

  def before_save
    puts "Track before_save #{associations[:release]&.object_id}"
  end
end

puts "Creation w/ nested_attributes"
Release.create \
  title: "Release",
  tracks_attributes: [{
    title: "Track"
  }]

puts
puts "Creation using adder w/ given reciprocal reference"
release = Release.create \
  title: "Release"

puts "Release id: #{release.object_id}"
release.add_track \
  release: release,
  title: "Track"

puts
puts "Lots of queries"
class Track < Sequel::Model
  def validate
    super

    errors.add :title, "should not be the same as the release title for whatever reason" if title == release.title
    puts "Track validate #{associations[:release]&.object_id}"
  end
end

Release.create \
  title: "Release",
  tracks_attributes: 100.times.collect{ |i| { title: "Track #{i}" } }

puts
puts "Loads association given id"

release = Release.create \
  title: "Release"

Track.create \
  release: nil,
  release_id: release.id