ActiveRecord. Double validation with autosave: true on both sides

[EPecherkin]

Steps to reproduce

#!/usr/bin/env ruby
# frozen_string_literal: true

require "bundler/inline"

gemfile(true) do
  source "https://rubygems.org"

  git_source(:github) { |repo| "https://github.com/#{repo}.git" }

  gem "rails", github: "rails/rails"
  gem "sqlite3"
end

require "active_record"
require "minitest/autorun"
require "logger"

# This connection will do for database-independent bug reports.
ActiveRecord::Base.establish_connection(adapter: "sqlite3", database: ":memory:")
ActiveRecord::Base.logger = Logger.new(STDOUT)

ActiveRecord::Schema.define do
  create_table :stories do |t|
    t.string :type
  end

  create_table :bad_guys do |t|
    t.references :story
  end
end

::VALIDATED = 0

class Story < ActiveRecord::Base
  has_one :bad_guy, foreign_key: :story_id, inverse_of: :story, autosave: true

  validate { ::VALIDATED += 1 }
end

class BadGuy < ActiveRecord::Base
  belongs_to :story, inverse_of: :bad_guy, autosave: true
end

class TestDoubleValidation < Minitest::Test
  def test_validated_once
    story = Story.new()
    bad_guy = BadGuy.new(story: story)
    story.save!
    assert_equal 1, VALIDATED
  end
end

Expected behavior

Story should be validated only once

Actual behavior

Story validated twice

System configuration

Rails version: master, 5.2.0

Ruby version: 2.5.1

[shime]

Setting the validate to false for association in BadGuy would make the test pass.

class BadGuy < ActiveRecord::Base
  belongs_to :story, class_name: 'DetectiveNovel', inverse_of: :bad_guy, autosave: true, validate: false
end

@EPecherkin does that help?

[EPecherkin]

@shime it doesn't really. I need to have autosave: true on both sides

[robertasg]

I've opened a PR a while ago to take care of this #31381

I assume this should solve your issue. I'll rebase it a bit. We can try to work off that.

[mvaragnat]

I'd love to see the PR merge. Right now we have the issue and use an ugly fix (override changed_for_autosave? in the parent in the specific case causing us problem)