path: root/activerecord/test/cases/associations/nested_has_many_through_associations_test.rb

require "cases/helper"
require 'models/author'
require 'models/post'
require 'models/person'
require 'models/reference'
require 'models/job'
require 'models/reader'
require 'models/comment'
require 'models/tag'
require 'models/tagging'
require 'models/owner'
require 'models/pet'
require 'models/toy'
require 'models/contract'
require 'models/company'
require 'models/developer'
require 'models/subscriber'
require 'models/book'
require 'models/subscription'
require 'models/rating'

# NOTE: Some of these tests might not really test "nested" HMT associations, as opposed to ones which
# are just one level deep. But it's all the same thing really, as the "nested" code is being 
# written in a generic way which applies to "non-nested" HMT associations too. So let's just shove
# all useful tests in here for now and then work out where they ought to live properly later.

class NestedHasManyThroughAssociationsTest < ActiveRecord::TestCase
  fixtures :authors, :books, :posts, :subscriptions, :subscribers, :tags, :taggings,
           :people, :readers, :references, :jobs, :ratings, :comments

  # Through associations can either use the has_many or has_one macros.
  # 
  # has_many
  #   - Source reflection can be has_many, has_one, belongs_to or has_and_belongs_to_many
  #   - Through reflection can be has_many, has_one, belongs_to or has_and_belongs_to_many
  # 
  # has_one
  #   - Source reflection can be has_one or belongs_to
  #   - Through reflection can be has_one or belongs_to
  # 
  # Additionally, the source reflection and/or through reflection may be subject to
  # polymorphism and/or STI.
  # 
  # When testing these, we need to make sure it works via loading the association directly, or
  # joining the association, or including the association. We also need to ensure that associations
  # are readonly where relevant.

  # has_many through
  # Source: has_many through
  # Through: has_many
  def test_has_many_through_a_has_many_through_association_on_source_reflection
    author = authors(:david)
    assert_equal [tags(:general), tags(:general)], author.tags
    
    # Only David has a Post tagged with General
    authors = Author.joins(:tags).where('tags.id' => tags(:general).id)
    assert_equal [authors(:david)], authors.uniq
    
    # This ensures that the polymorphism of taggings is being observed correctly
    authors = Author.joins(:tags).where('taggings.taggable_type' => 'FakeModel')
    assert authors.empty?
  end

  # has_many through
  # Source: has_many
  # Through: has_many through
  def test_has_many_through_a_has_many_through_association_on_through_reflection
    author = authors(:david)
    assert_equal [subscribers(:first), subscribers(:second), subscribers(:second)], author.subscribers
    
    # All authors with subscribers where one of the subscribers' nick is 'alterself'
    authors = Author.joins(:subscribers).where('subscribers.nick' => 'alterself')
    assert_equal [authors(:david)], authors
  end
  
  # TODO: has_many through
  # Source: has_one through
  # Through: has_one
  
  # TODO: has_many through
  # Source: has_one
  # Through: has_one through
  
  # TODO: has_many through
  # Source: has_many through
  # Through: has_one
  
  # TODO: has_many through
  # Source: has_many
  # Through: has_one through
  
  # TODO: has_many through
  # Source: has_and_belongs_to_many
  # Through: has_many
  
  # TODO: has_many through
  # Source: has_many
  # Through: has_and_belongs_to_many
  
  # TODO: has_many through
  # Source: belongs_to
  # Through: has_many through
  
  # TODO: has_many through
  # Source: has_many through
  # Through: belongs_to
  
  # TODO: has_one through
  # Source: has_one through
  # Through: has_one
  
  # TODO: has_one through
  # Source: belongs_to
  # Through: has_one through

  def test_distinct_has_many_through_a_has_many_through_association_on_source_reflection
    author = authors(:david)
    assert_equal [tags(:general)], author.distinct_tags
  end

  def test_distinct_has_many_through_a_has_many_through_association_on_through_reflection
    author = authors(:david)
    assert_equal [subscribers(:first), subscribers(:second)], author.distinct_subscribers
  end
  
  def test_nested_has_many_through_with_a_table_referenced_multiple_times
    author = authors(:bob)
    assert_equal [posts(:misc_by_bob), posts(:misc_by_mary)], author.similar_posts.sort_by(&:id)
    
    # Mary and Bob both have posts in misc, but they are the only ones.
    authors = Author.joins(:similar_posts).where('posts.id' => posts(:misc_by_bob).id)
    assert_equal [authors(:mary), authors(:bob)], authors.uniq.sort_by(&:id)
    
    # Check the polymorphism of taggings is being observed correctly (in both joins)
    authors = Author.joins(:similar_posts).where('taggings.taggable_type' => 'FakeModel')
    assert authors.empty?
    authors = Author.joins(:similar_posts).where('taggings_authors_join.taggable_type' => 'FakeModel')
    assert authors.empty?
  end
  
  def test_has_many_through_with_foreign_key_option_on_through_reflection
    assert_equal [posts(:welcome), posts(:authorless)], people(:david).agents_posts
    assert_equal [authors(:david)], references(:david_unicyclist).agents_posts_authors
    
    references = Reference.joins(:agents_posts_authors).where('authors.id' => authors(:david).id)
    assert_equal [references(:david_unicyclist)], references
  end
  
  def test_has_many_through_with_foreign_key_option_on_source_reflection
    assert_equal [people(:michael), people(:susan)], jobs(:unicyclist).agents
    
    jobs = Job.joins(:agents)
    assert_equal [jobs(:unicyclist), jobs(:unicyclist)], jobs
  end

  def test_has_many_through_with_sti_on_through_reflection
    ratings = posts(:sti_comments).special_comments_ratings.sort_by(&:id)
    assert_equal [ratings(:special_comment_rating), ratings(:sub_special_comment_rating)], ratings
    
    # Ensure STI is respected in the join
    scope = Post.joins(:special_comments_ratings).where(:id => posts(:sti_comments).id)
    assert scope.where("comments.type" => "Comment").empty?
    assert !scope.where("comments.type" => "SpecialComment").empty?
    assert !scope.where("comments.type" => "SubSpecialComment").empty?
  end
end