bug.rb

# frozen_string_literal: true

# Create postgres table `bug_report` before running this test

require "bundler/inline"

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

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

  # Activate the gem you are reporting the issue against.
  gem "rails", github: "rails/rails", branch: '6-1-stable'
  gem "pg"
end

require "active_record"
require "minitest/autorun"
require "logger"
require 'active_support/testing/assertions'

ActiveRecord::Base.has_many_inversing = true

ActiveRecord::Base.establish_connection(adapter: "postgresql", database: "bug_report")
ActiveRecord::Base.logger = Logger.new(STDOUT)

ActiveRecord::Schema.define do
  create_table :events, force: true, id: :uuid, default: -> { "gen_random_uuid()" } do |t|
  end

  create_table :event_applications, force: true, id: :uuid, default: -> { "gen_random_uuid()" } do |t|
    t.references :event, type: :uuid, null: false
  end
end

class Event < ActiveRecord::Base
  has_many :applications, class_name: 'EventApplication', inverse_of: :event, dependent: :destroy
end

class EventApplication < ActiveRecord::Base
  belongs_to :event, inverse_of: :applications, touch: true
end

class BugTest < Minitest::Test
  include ActiveSupport::Testing::Assertions

  def test_association_stuff
    event = Event.create!
    event.applications.create!

    assert_difference 'EventApplication.count', -1 do
      EventApplication.last.destroy
    end
  end
end