overridden_from.rb

unless File.exist?('Gemfile')
  File.write('Gemfile', <<-GEMFILE)
    source 'https://rubygems.org'
    gem 'rails', github: 'rails/rails'
    gem 'sqlite3'
  GEMFILE

  system 'bundle'
end

require 'bundler'
Bundler.setup(:default)

require 'active_record'
require 'minitest/autorun'
require 'logger'

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

ActiveRecord::Base.establish_connection(adapter: 'sqlite3', database: ':memory:')
ActiveRecord::Base.logger = Logger.new(STDOUT)

# Schema
ActiveRecord::Schema.define do
  ActiveRecord::Base.connection.create_table(:blogs) do |t|
  end

  ActiveRecord::Base.connection.create_table(:posts) do |t|
    t.integer :blog_id
    t.string :title
  end
end

# Models
class Blog < ActiveRecord::Base
  has_many :posts
  has_many :filtered_posts, -> do 
    from("(select * from posts where title like '%post2') as posts") 
  end, class_name: 'Post'
end

class Post < ActiveRecord::Base
  belongs_to :blog
end

class BugTest < Minitest::Test

  def test_scope_with_from
    blog = Blog.create!
    blog.posts.create!(title: 'blog1-post1') 
    blog.posts.create!(title: 'blog1-post2')

    assert_equal(1, blog.filtered_posts.to_a.size)
  end
end