Test case for ActiveRecord filter_binds bug

bind_filter_bug.rb

# Activate the gem you are reporting the issue against.
gem 'activerecord', '4.1.1'
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: 'postgresql', database: 'test_ar')
ActiveRecord::Base.logger = Logger.new(STDOUT)

ActiveRecord::Schema.define do
  create_table :posts do |t|
    t.string :title
    t.text :authors
    t.timestamps
  end

  create_table :comments do |t|
    t.string :comment_text
    t.string :author
    t.integer :parent_post_id
    t.timestamps
  end
end

class Post < ActiveRecord::Base
  # Changing the foreign_key parameter from a symbol to a string makes this test pass!
  has_many :comments, foreign_key: :parent_post_id

  before_save do |post|
    post.authors = post.comments.map(&:author).to_sentence
  end
end

class Comment < ActiveRecord::Base
  belongs_to :post, foreign_key: :parent_post_id
  
  after_save do |comment|
    comment.post.updated_at = Time.now
    comment.post.save(validate: false)
  end
end

class BugTest < Minitest::Test
  def test_creating_comments
    post = Post.create!(title: "First Post")
    post.comments.where(comment_text: "First comment!").first_or_create
  end
end