issue35666.rb

# frozen_string_literal: true

begin
  require "bundler/inline"
rescue LoadError => e
  $stderr.puts "Bundler version 1.10 or later is required. Please update your Bundler"
  raise e
end

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 "activerecord", "5.1.5"
  gem "rails", github: 'rails/rails'
  gem "byebug"
  gem "sqlite3"
end

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

# Ensure backward compatibility with Minitest 4
Minitest::Test = MiniTest::Unit::TestCase unless defined?(Minitest::Test)

# 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 :projects, force: true do |t|
    t.string :name
  end
end

class Project < ActiveRecord::Base
  def self.create_new
    Project.new
  end
end

class BugTest < Minitest::Test

  def test_id_leak_to_object
    project = Project.where(id: 1)
    new_project = project.create_new
    assert_nil new_project.id, nil
  end

  def test_name_leak_to_object
    project = Project.where(id: 1, name: 'noop')
    new_project = project.create_new
    assert_nil new_project.name, nil
  end
end