# frozen_string_literal: true

require "active_record"

ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:")

ActiveRecord::Schema.define do

create_table :users, force: true do |t|

t.string :name

t.timestamps null: false

end

create_table :topics, force: true do |t|

t.string :title

t.integer :user_id

t.timestamps null: false

end

end

class Topic < ActiveRecord::Base

belongs_to :user

end

class User < ActiveRecord::Base

has_many :topics

end

user = User.create!(name: "user name")

topic = user.topics.build(title: "topic title")

# Benchmark.ips do |x|

# x.report("changed?") { topic.changed? }

# x.report("changed") { topic.changed }

# x.report("changes") { topic.changes }

# x.report("changed_attributes") { topic.changed_attributes }

# x.report("title_change") { topic.title_change }

# x.report("title_was") { topic.title_was }

# end

Benchmark.bm { |x|

x.report("title_was") {

1_000_000.times {

topic.title_was

}

}

}