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

require "cases/helper"
require "models/post"
require "models/tagging"
require "models/tag"
require "models/comment"
require "models/author"
require "models/essay"
require "models/category"
require "models/company"
require "models/person"
require "models/reader"
require "models/owner"
require "models/pet"
require "models/reference"
require "models/job"
require "models/subscriber"
require "models/subscription"
require "models/book"
require "models/developer"
require "models/computer"
require "models/project"
require "models/member"
require "models/membership"
require "models/club"
require "models/categorization"
require "models/sponsor"
require "models/mentor"
require "models/contract"

class EagerAssociationTest < ActiveRecord::TestCase
  fixtures :posts, :comments, :authors, :essays, :author_addresses, :categories, :categories_posts,
            :companies, :accounts, :tags, :taggings, :people, :readers, :categorizations,
            :owners, :pets, :author_favorites, :jobs, :references, :subscribers, :subscriptions, :books,
            :developers, :projects, :developers_projects, :members, :memberships, :clubs, :sponsors

  def test_eager_with_has_one_through_join_model_with_conditions_on_the_through
    member = Member.all.merge!(includes: :favourite_club).find(members(:some_other_guy).id)
    assert_nil member.favourite_club
  end

  def test_loading_with_one_association
    posts = Post.all.merge!(includes: :comments).to_a
    post = posts.find { |p| p.id == 1 }
    assert_equal 2, post.comments.size
    assert_includes post.comments, comments(:greetings)

    post = Post.all.merge!(includes: :comments, where: "posts.title = 'Welcome to the weblog'").first
    assert_equal 2, post.comments.size
    assert_includes post.comments, comments(:greetings)

    posts = Post.all.merge!(includes: :last_comment).to_a
    post = posts.find { |p| p.id == 1 }
    assert_equal Post.find(1).last_comment, post.last_comment
  end

  def test_loading_with_one_association_with_non_preload
    posts = Post.all.merge!(includes: :last_comment, order: "comments.id DESC").to_a
    post = posts.find { |p| p.id == 1 }
    assert_equal Post.find(1).last_comment, post.last_comment
  end

  def test_loading_conditions_with_or
    posts = authors(:david).posts.references(:comments).merge(
      includes: :comments,
      where: "comments.body like 'Normal%' OR comments.#{QUOTED_TYPE} = 'SpecialComment'"
    ).to_a
    assert_nil posts.detect { |p| p.author_id != authors(:david).id },
      "expected to find only david's posts"
  end

  def test_loading_with_scope_including_joins
    assert_equal clubs(:boring_club), Member.preload(:general_club).find(1).general_club
    assert_equal clubs(:boring_club), Member.eager_load(:general_club).find(1).general_club
  end

  def test_with_ordering
    list = Post.all.merge!(includes: :comments, order: "posts.id DESC").to_a
    [:other_by_mary, :other_by_bob, :misc_by_mary, :misc_by_bob, :eager_other,
     :sti_habtm, :sti_post_and_comments, :sti_comments, :authorless, :thinking, :welcome
    ].each_with_index do |post, index|
      assert_equal posts(post), list[index]
    end
  end

  def test_has_many_through_with_order
    authors = Author.includes(:favorite_authors).to_a
    assert authors.count > 0
    assert_no_queries { authors.map(&:favorite_authors) }
  end

  def test_eager_loaded_has_one_association_with_references_does_not_run_additional_queries
    Post.update_all(author_id: nil)
    authors = Author.includes(:post).references(:post).to_a
    assert authors.count > 0
    assert_no_queries { authors.map(&:post) }
  end

  def test_calculate_with_string_in_from_and_eager_loading
    assert_equal 10, Post.from("authors, posts").eager_load(:comments).where("posts.author_id = authors.id").count
  end

  def test_with_two_tables_in_from_without_getting_double_quoted
    posts = Post.select("posts.*").from("authors, posts").eager_load(:comments).where("posts.author_id = authors.id").order("posts.id").to_a
    assert_equal 2, posts.first.comments.size
  end

  def test_loading_with_multiple_associations
    posts = Post.all.merge!(includes: [ :comments, :author, :categories ], order: "posts.id").to_a
    assert_equal 2, posts.first.comments.size
    assert_equal 2, posts.first.categories.size
    assert_includes posts.first.comments, comments(:greetings)
  end

  def test_duplicate_middle_objects
    comments = Comment.all.merge!(where: "post_id = 1", includes: [post: :author]).to_a
    assert_no_queries do
      comments.each { |comment| comment.post.author.name }
    end
  end

  def test_preloading_has_many_in_multiple_queries_with_more_ids_than_database_can_handle
    assert_called(Comment.connection, :in_clause_length, returns: 5) do
      posts = Post.all.merge!(includes: :comments).to_a
      assert_equal 11, posts.size
    end
  end

  def test_preloading_has_many_in_one_queries_when_database_has_no_limit_on_ids_it_can_handle
    assert_called(Comment.connection, :in_clause_length, returns: nil) do
      posts = Post.all.merge!(includes: :comments).to_a
      assert_equal 11, posts.size
    end
  end

  def test_preloading_habtm_in_multiple_queries_with_more_ids_than_database_can_handle
    assert_called(Comment.connection, :in_clause_length, times: 2, returns: 5) do
      posts = Post.all.merge!(includes: :categories).to_a
      assert_equal 11, posts.size
    end
  end

  def test_preloading_habtm_in_one_queries_when_database_has_no_limit_on_ids_it_can_handle
    assert_called(Comment.connection, :in_clause_length, times: 2, returns: nil) do
      posts = Post.all.merge!(includes: :categories).to_a
      assert_equal 11, posts.size
    end
  end

  def test_load_associated_records_in_one_query_when_adapter_has_no_limit
    assert_called(Comment.connection, :in_clause_length, returns: nil) do
      post = posts(:welcome)
      assert_queries(2) do
        Post.includes(:comments).where(id: post.id).to_a
      end
    end
  end

  def test_load_associated_records_in_several_queries_when_many_ids_passed
    assert_called(Comment.connection, :in_clause_length, returns: 1) do
      post1, post2 = posts(:welcome), posts(:thinking)
      assert_queries(3) do
        Post.includes(:comments).where(id: [post1.id, post2.id]).to_a
      end
    end
  end

  def test_load_associated_records_in_one_query_when_a_few_ids_passed
    assert_called(Comment.connection, :in_clause_length, returns: 3) do
      post = posts(:welcome)
      assert_queries(2) do
        Post.includes(:comments).where(id: post.id).to_a
      end
    end
  end

  def test_including_duplicate_objects_from_belongs_to
    popular_post = Post.create!(title: "foo", body: "I like cars!")
    comment = popular_post.comments.create!(body: "lol")
    popular_post.readers.create!(person: people(:michael))
    popular_post.readers.create!(person: people(:david))

    readers = Reader.all.merge!(where: ["post_id = ?", popular_post.id],
                                includes: { post: :comments }).to_a
    readers.each do |reader|
      assert_equal [comment], reader.post.comments
    end
  end

  def test_including_duplicate_objects_from_has_many
    car_post = Post.create!(title: "foo", body: "I like cars!")
    car_post.categories << categories(:general)
    car_post.categories << categories(:technology)

    comment = car_post.comments.create!(body: "hmm")
    categories = Category.all.merge!(where: { "posts.id" => car_post.id },
                                 includes: { posts: :comments }).to_a
    categories.each do |category|
      assert_equal [comment], category.posts[0].comments
    end
  end

  def test_associations_loaded_for_all_records
    post = Post.create!(title: "foo", body: "I like cars!")
    SpecialComment.create!(body: "Come on!", post: post)
    first_category = Category.create! name: "First!", posts: [post]
    second_category = Category.create! name: "Second!", posts: [post]

    categories = Category.where(id: [first_category.id, second_category.id]).includes(posts: :special_comments)
    assert_equal categories.map { |category| category.posts.first.special_comments.loaded? }, [true, true]
  end

  def test_finding_with_includes_on_has_many_association_with_same_include_includes_only_once
    author_id = authors(:david).id
    author = assert_queries(3) { Author.all.merge!(includes: { posts_with_comments: :comments }).find(author_id) } # find the author, then find the posts, then find the comments
    author.posts_with_comments.each do |post_with_comments|
      assert_equal post_with_comments.comments.length, post_with_comments.comments.count
      assert_nil post_with_comments.comments.to_a.uniq!
    end
  end

  def test_finding_with_includes_on_has_one_association_with_same_include_includes_only_once
    author = authors(:david)
    post = author.post_about_thinking_with_last_comment
    last_comment = post.last_comment
    author = assert_queries(3) { Author.all.merge!(includes: { post_about_thinking_with_last_comment: :last_comment }).find(author.id) } # find the author, then find the posts, then find the comments
    assert_no_queries do
      assert_equal post, author.post_about_thinking_with_last_comment
      assert_equal last_comment, author.post_about_thinking_with_last_comment.last_comment
    end
  end

  def test_finding_with_includes_on_belongs_to_association_with_same_include_includes_only_once
    post = posts(:welcome)
    author = post.author
    author_address = author.author_address
    post = assert_queries(3) { Post.all.merge!(includes: { author_with_address: :author_address }).find(post.id) } # find the post, then find the author, then find the address
    assert_no_queries do
      assert_equal author, post.author_with_address
      assert_equal author_address, post.author_with_address.author_address
    end
  end

  def test_finding_with_includes_on_null_belongs_to_association_with_same_include_includes_only_once
    post = posts(:welcome)
    post.update!(author: nil)
    post = assert_queries(1) { Post.all.merge!(includes: { author_with_address: :author_address }).find(post.id) }
    # find the post, then find the author which is null so no query for the author or address
    assert_no_queries do
      assert_nil post.author_with_address
    end
  end

  def test_finding_with_includes_on_null_belongs_to_polymorphic_association
    sponsor = sponsors(:moustache_club_sponsor_for_groucho)
    sponsor.update!(sponsorable: nil)
    sponsor = assert_queries(1) { Sponsor.all.merge!(includes: :sponsorable).find(sponsor.id) }
    assert_no_queries do
      assert_nil sponsor.sponsorable
    end
  end

  def test_finding_with_includes_on_empty_polymorphic_type_column
    sponsor = sponsors(:moustache_club_sponsor_for_groucho)
    sponsor.update!(sponsorable_type: "", sponsorable_id: nil) # sponsorable_type column might be declared NOT NULL
    sponsor = assert_queries(1) do
      assert_nothing_raised { Sponsor.all.merge!(includes: :sponsorable).find(sponsor.id) }
    end
    assert_no_queries do
      assert_nil sponsor.sponsorable
    end
  end

  def test_loading_from_an_association
    posts = authors(:david).posts.merge(includes: :comments, order: "posts.id").to_a
    assert_equal 2, posts.first.comments.size
  end

  def test_loading_from_an_association_that_has_a_hash_of_conditions
    assert !Author.all.merge!(includes: :hello_posts_with_hash_conditions).find(authors(:david).id).hello_posts.empty?
  end

  def test_loading_with_no_associations
    assert_nil Post.all.merge!(includes: :author).find(posts(:authorless).id).author
  end

  # Regression test for 21c75e5
  def test_nested_loading_does_not_raise_exception_when_association_does_not_exist
    assert_nothing_raised do
      Post.all.merge!(includes: { author: :author_addresss }).find(posts(:authorless).id)
    end
  end

  def test_three_level_nested_preloading_does_not_raise_exception_when_association_does_not_exist
    post_id = Comment.where(author_id: nil).where.not(post_id: nil).first.post_id

    assert_nothing_raised do
      Post.preload(comments: [{ author: :essays }]).find(post_id)
    end
  end

  def test_nested_loading_through_has_one_association
    aa = AuthorAddress.all.merge!(includes: { author: :posts }).find(author_addresses(:david_address).id)
    assert_equal aa.author.posts.count, aa.author.posts.length
  end

  def test_nested_loading_through_has_one_association_with_order
    aa = AuthorAddress.all.merge!(includes: { author: :posts }, order: "author_addresses.id").find(author_addresses(:david_address).id)
    assert_equal aa.author.posts.count, aa.author.posts.length
  end

  def test_nested_loading_through_has_one_association_with_order_on_association
    aa = AuthorAddress.all.merge!(includes: { author: :posts }, order: "authors.id").find(author_addresses(:david_address).id)
    assert_equal aa.author.posts.count, aa.author.posts.length
  end

  def test_nested_loading_through_has_one_association_with_order_on_nested_association
    aa = AuthorAddress.all.merge!(includes: { author: :posts }, order: "posts.id").find(author_addresses(:david_address).id)
    assert_equal aa.author.posts.count, aa.author.posts.length
  end

  def test_nested_loading_through_has_one_association_with_conditions
    aa = AuthorAddress.references(:author_addresses).merge(
      includes: { author: :posts },
      where: "author_addresses.id > 0"
    ).find author_addresses(:david_address).id
    assert_equal aa.author.posts.count, aa.author.posts.length
  end

  def test_nested_loading_through_has_one_association_with_conditions_on_association
    aa = AuthorAddress.references(:authors).merge(
      includes: { author: :posts },
      where: "authors.id > 0"
    ).find author_addresses(:david_address).id
    assert_equal aa.author.posts.count, aa.author.posts.length
  end

  def test_nested_loading_through_has_one_association_with_conditions_on_nested_association
    aa = AuthorAddress.references(:posts).merge(
      includes: { author: :posts },
      where: "posts.id > 0"
    ).find author_addresses(:david_address).id
    assert_equal aa.author.posts.count, aa.author.posts.length
  end

  def test_eager_association_loading_with_belongs_to_and_foreign_keys
    pets = Pet.all.merge!(includes: :owner).to_a
    assert_equal 4, pets.length
  end

  def test_eager_association_loading_with_belongs_to
    comments = Comment.all.merge!(includes: :post).to_a
    assert_equal 11, comments.length
    titles = comments.map { |c| c.post.title }
    assert_includes titles, posts(:welcome).title
    assert_includes titles, posts(:sti_post_and_comments).title
  end

  def test_eager_association_loading_with_belongs_to_and_limit
    comments = Comment.all.merge!(includes: :post, limit: 5, order: "comments.id").to_a
    assert_equal 5, comments.length
    assert_equal [1, 2, 3, 5, 6], comments.collect(&:id)
  end

  def test_eager_association_loading_with_belongs_to_and_limit_and_conditions
    comments = Comment.all.merge!(includes: :post, where: "post_id = 4", limit: 3, order: "comments.id").to_a
    assert_equal 3, comments.length
    assert_equal [5, 6, 7], comments.collect(&:id)
  end

  def test_eager_association_loading_with_belongs_to_and_limit_and_offset
    comments = Comment.all.merge!(includes: :post, limit: 3, offset: 2, order: "comments.id").to_a
    assert_equal 3, comments.length
    assert_equal [3, 5, 6], comments.collect(&:id)
  end

  def test_eager_association_loading_with_belongs_to_and_limit_and_offset_and_conditions
    comments = Comment.all.merge!(includes: :post, where: "post_id = 4", limit: 3, offset: 1, order: "comments.id").to_a
    assert_equal 3, comments.length
    assert_equal [6, 7, 8], comments.collect(&:id)
  end

  def test_eager_association_loading_with_belongs_to_and_limit_and_offset_and_conditions_array
    comments = Comment.all.merge!(includes: :post, where: ["post_id = ?", 4], limit: 3, offset: 1, order: "comments.id").to_a
    assert_equal 3, comments.length
    assert_equal [6, 7, 8], comments.collect(&:id)
  end

  def test_eager_association_loading_with_belongs_to_and_conditions_string_with_unquoted_table_name
    assert_nothing_raised do
      Comment.includes(:post).references(:posts).where("posts.id = ?", 4)
    end
  end

  def test_eager_association_loading_with_belongs_to_and_conditions_hash
    comments = []
    assert_nothing_raised do
      comments = Comment.all.merge!(includes: :post, where: { posts: { id: 4 } }, limit: 3, order: "comments.id").to_a
    end
    assert_equal 3, comments.length
    assert_equal [5, 6, 7], comments.collect(&:id)
    assert_no_queries do
      comments.first.post
    end
  end

  def test_eager_association_loading_with_belongs_to_and_conditions_string_with_quoted_table_name
    quoted_posts_id = Comment.connection.quote_table_name("posts") + "." + Comment.connection.quote_column_name("id")
    assert_nothing_raised do
      Comment.includes(:post).references(:posts).where("#{quoted_posts_id} = ?", 4)
    end
  end

  def test_eager_association_loading_with_belongs_to_and_order_string_with_unquoted_table_name
    assert_nothing_raised do
      Comment.all.merge!(includes: :post, order: "posts.id").to_a
    end
  end

  def test_eager_association_loading_with_belongs_to_and_order_string_with_quoted_table_name
    quoted_posts_id = Comment.connection.quote_table_name("posts") + "." + Comment.connection.quote_column_name("id")
    assert_nothing_raised do
      Comment.includes(:post).references(:posts).order(quoted_posts_id)
    end
  end

  def test_eager_association_loading_with_belongs_to_and_limit_and_multiple_associations
    posts = Post.all.merge!(includes: [:author, :very_special_comment], limit: 1, order: "posts.id").to_a
    assert_equal 1, posts.length
    assert_equal [1], posts.collect(&:id)
  end

  def test_eager_association_loading_with_belongs_to_and_limit_and_offset_and_multiple_associations
    posts = Post.all.merge!(includes: [:author, :very_special_comment], limit: 1, offset: 1, order: "posts.id").to_a
    assert_equal 1, posts.length
    assert_equal [2], posts.collect(&:id)
  end

  def test_eager_association_loading_with_belongs_to_inferred_foreign_key_from_association_name
    author_favorite = AuthorFavorite.all.merge!(includes: :favorite_author).first
    assert_equal authors(:mary), assert_no_queries { author_favorite.favorite_author }
  end

  def test_eager_load_belongs_to_quotes_table_and_column_names
    job = Job.includes(:ideal_reference).find jobs(:unicyclist).id
    references(:michael_unicyclist)
    assert_no_queries { assert_equal references(:michael_unicyclist), job.ideal_reference }
  end

  def test_eager_load_has_one_quotes_table_and_column_names
    michael = Person.all.merge!(includes: :favourite_reference).find(people(:michael).id)
    references(:michael_unicyclist)
    assert_no_queries { assert_equal references(:michael_unicyclist), michael.favourite_reference }
  end

  def test_eager_load_has_many_quotes_table_and_column_names
    michael = Person.all.merge!(includes: :references).find(people(:michael).id)
    references(:michael_magician, :michael_unicyclist)
    assert_no_queries { assert_equal references(:michael_magician, :michael_unicyclist), michael.references.sort_by(&:id) }
  end

  def test_eager_load_has_many_through_quotes_table_and_column_names
    michael = Person.all.merge!(includes: :jobs).find(people(:michael).id)
    jobs(:magician, :unicyclist)
    assert_no_queries { assert_equal jobs(:unicyclist, :magician), michael.jobs.sort_by(&:id) }
  end

  def test_eager_load_has_many_with_string_keys
    subscriptions = subscriptions(:webster_awdr, :webster_rfr)
    subscriber = Subscriber.all.merge!(includes: :subscriptions).find(subscribers(:second).id)
    assert_equal subscriptions, subscriber.subscriptions.sort_by(&:id)
  end

  def test_string_id_column_joins
    s = Subscriber.create! do |c|
      c.id = "PL"
    end

    b = Book.create!

    Subscription.create!(subscriber_id: "PL", book_id: b.id)
    s.reload
    s.book_ids = s.book_ids
  end

  def test_eager_load_has_many_through_with_string_keys
    books = books(:awdr, :rfr)
    subscriber = Subscriber.all.merge!(includes: :books).find(subscribers(:second).id)
    assert_equal books, subscriber.books.sort_by(&:id)
  end

  def test_eager_load_belongs_to_with_string_keys
    subscriber = subscribers(:second)
    subscription = Subscription.all.merge!(includes: :subscriber).find(subscriptions(:webster_awdr).id)
    assert_equal subscriber, subscription.subscriber
  end

  def test_eager_association_loading_with_explicit_join
    posts = Post.all.merge!(includes: :comments, joins: "INNER JOIN authors ON posts.author_id = authors.id AND authors.name = 'Mary'", limit: 1, order: "author_id").to_a
    assert_equal 1, posts.length
  end

  def test_eager_with_has_many_through
    posts_with_comments = people(:michael).posts.merge(includes: :comments, order: "posts.id").to_a
    posts_with_author = people(:michael).posts.merge(includes: :author, order: "posts.id").to_a
    posts_with_comments_and_author = people(:michael).posts.merge(includes: [ :comments, :author ], order: "posts.id").to_a
    assert_equal 2, posts_with_comments.inject(0) { |sum, post| sum + post.comments.size }
    assert_equal authors(:david), assert_no_queries { posts_with_author.first.author }
    assert_equal authors(:david), assert_no_queries { posts_with_comments_and_author.first.author }
  end

  def test_eager_with_has_many_through_a_belongs_to_association
    author = authors(:mary)
    Post.create!(author: author, title: "TITLE", body: "BODY")
    author.author_favorites.create(favorite_author_id: 1)
    author.author_favorites.create(favorite_author_id: 2)
    posts_with_author_favorites = author.posts.merge(includes: :author_favorites).to_a
    assert_no_queries { posts_with_author_favorites.first.author_favorites.first.author_id }
  end

  def test_eager_with_has_many_through_an_sti_join_model
    author = Author.all.merge!(includes: :special_post_comments, order: "authors.id").first
    assert_equal [comments(:does_it_hurt)], assert_no_queries { author.special_post_comments }
  end

  def test_eager_with_has_many_through_an_sti_join_model_with_conditions_on_both
    author = Author.all.merge!(includes: :special_nonexistent_post_comments, order: "authors.id").first
    assert_equal [], author.special_nonexistent_post_comments
  end

  def test_eager_with_has_many_through_join_model_with_conditions
    assert_equal Author.all.merge!(includes: :hello_post_comments,
                             order: "authors.id").first.hello_post_comments.sort_by(&:id),
                 Author.all.merge!(order: "authors.id").first.hello_post_comments.sort_by(&:id)
  end

  def test_eager_with_has_many_through_join_model_with_conditions_on_top_level
    assert_equal comments(:more_greetings), Author.all.merge!(includes: :comments_with_order_and_conditions).find(authors(:david).id).comments_with_order_and_conditions.first
  end

  def test_eager_with_has_many_through_join_model_with_include
    author_comments = Author.all.merge!(includes: :comments_with_include).find(authors(:david).id).comments_with_include.to_a
    assert_no_queries do
      author_comments.first.post.title
    end
  end

  def test_eager_with_has_many_through_with_conditions_join_model_with_include
    post_tags = Post.find(posts(:welcome).id).misc_tags
    eager_post_tags = Post.all.merge!(includes: :misc_tags).find(1).misc_tags
    assert_equal post_tags, eager_post_tags
  end

  def test_eager_with_has_many_through_join_model_ignores_default_includes
    assert_nothing_raised do
      authors(:david).comments_on_posts_with_default_include.to_a
    end
  end

  def test_eager_with_has_many_and_limit
    posts = Post.all.merge!(order: "posts.id asc", includes: [ :author, :comments ], limit: 2).to_a
    assert_equal 2, posts.size
    assert_equal 3, posts.inject(0) { |sum, post| sum + post.comments.size }
  end

  def test_eager_with_has_many_and_limit_and_conditions
    posts = Post.all.merge!(includes: [ :author, :comments ], limit: 2, where: "posts.body = 'hello'", order: "posts.id").to_a
    assert_equal 2, posts.size
    assert_equal [4, 5], posts.collect(&:id)
  end

  def test_eager_with_has_many_and_limit_and_conditions_array
    posts = Post.all.merge!(includes: [ :author, :comments ], limit: 2, where: [ "posts.body = ?", "hello" ], order: "posts.id").to_a
    assert_equal 2, posts.size
    assert_equal [4, 5], posts.collect(&:id)
  end

  def test_eager_with_has_many_and_limit_and_conditions_array_on_the_eagers
    posts = Post.includes(:author, :comments).limit(2).references(:author).where("authors.name = ?", "David")
    assert_equal 2, posts.size

    count = Post.includes(:author, :comments).limit(2).references(:author).where("authors.name = ?", "David").count
    assert_equal posts.size, count
  end

  def test_eager_with_has_many_and_limit_and_high_offset
    posts = Post.all.merge!(includes: [ :author, :comments ], limit: 2, offset: 10, where: { "authors.name" => "David" }).to_a
    assert_equal 0, posts.size
  end

  def test_eager_with_has_many_and_limit_and_high_offset_and_multiple_array_conditions
    assert_queries(1) do
      posts = Post.references(:authors, :comments).
        merge(includes: [ :author, :comments ], limit: 2, offset: 10,
          where: [ "authors.name = ? and comments.body = ?", "David", "go crazy" ]).to_a
      assert_equal 0, posts.size
    end
  end

  def test_eager_with_has_many_and_limit_and_high_offset_and_multiple_hash_conditions
    assert_queries(1) do
      posts = Post.all.merge!(includes: [ :author, :comments ], limit: 2, offset: 10,
        where: { "authors.name" => "David", "comments.body" => "go crazy" }).to_a
      assert_equal 0, posts.size
    end
  end

  def test_count_eager_with_has_many_and_limit_and_high_offset
    posts = Post.all.merge!(includes: [ :author, :comments ], limit: 2, offset: 10, where: { "authors.name" => "David" }).count(:all)
    assert_equal 0, posts
  end

  def test_eager_with_has_many_and_limit_with_no_results
    posts = Post.all.merge!(includes: [ :author, :comments ], limit: 2, where: "posts.title = 'magic forest'").to_a
    assert_equal 0, posts.size
  end

  def test_eager_count_performed_on_a_has_many_association_with_multi_table_conditional
    author = authors(:david)
    author_posts_without_comments = author.posts.select { |post| post.comments.blank? }
    assert_equal author_posts_without_comments.size, author.posts.includes(:comments).where("comments.id is null").references(:comments).count
  end

  def test_eager_count_performed_on_a_has_many_through_association_with_multi_table_conditional
    person = people(:michael)
    person_posts_without_comments = person.posts.select { |post| post.comments.blank? }
    assert_equal person_posts_without_comments.size, person.posts_with_no_comments.count
  end

  def test_eager_with_has_and_belongs_to_many_and_limit
    posts = Post.all.merge!(includes: :categories, order: "posts.id", limit: 3).to_a
    assert_equal 3, posts.size
    assert_equal 2, posts[0].categories.size
    assert_equal 1, posts[1].categories.size
    assert_equal 0, posts[2].categories.size
    assert_includes posts[0].categories, categories(:technology)
    assert_includes posts[1].categories, categories(:general)
  end

  # Since the preloader for habtm gets raw row hashes from the database and then
  # instantiates them, this test ensures that it only instantiates one actual
  # object per record from the database.
  def test_has_and_belongs_to_many_should_not_instantiate_same_records_multiple_times
    welcome    = posts(:welcome)
    categories = Category.includes(:posts)

    general    = categories.find { |c| c == categories(:general) }
    technology = categories.find { |c| c == categories(:technology) }

    post1 = general.posts.to_a.find { |p| p == welcome }
    post2 = technology.posts.to_a.find { |p| p == welcome }

    assert_equal post1.object_id, post2.object_id
  end

  def test_eager_with_has_many_and_limit_and_conditions_on_the_eagers
    posts =
      authors(:david).posts
        .includes(:comments)
        .where("comments.body like 'Normal%' OR comments.#{QUOTED_TYPE}= 'SpecialComment'")
        .references(:comments)
        .limit(2)
        .to_a
    assert_equal 2, posts.size

    count =
      Post.includes(:comments, :author)
        .where("authors.name = 'David' AND (comments.body like 'Normal%' OR comments.#{QUOTED_TYPE}= 'SpecialComment')")
        .references(:authors, :comments)
        .limit(2)
        .count
    assert_equal count, posts.size
  end

  def test_eager_with_has_many_and_limit_and_scoped_conditions_on_the_eagers
    posts = nil
    Post.includes(:comments)
      .where("comments.body like 'Normal%' OR comments.#{QUOTED_TYPE}= 'SpecialComment'")
      .references(:comments)
      .scoping do

      posts = authors(:david).posts.limit(2).to_a
      assert_equal 2, posts.size
    end

    Post.includes(:comments, :author)
      .where("authors.name = 'David' AND (comments.body like 'Normal%' OR comments.#{QUOTED_TYPE}= 'SpecialComment')")
      .references(:authors, :comments)
      .scoping do

      count = Post.limit(2).count
      assert_equal count, posts.size
    end
  end

  def test_eager_association_loading_with_habtm
    posts = Post.all.merge!(includes: :categories, order: "posts.id").to_a
    assert_equal 2, posts[0].categories.size
    assert_equal 1, posts[1].categories.size
    assert_equal 0, posts[2].categories.size
    assert_includes posts[0].categories, categories(:technology)
    assert_includes posts[1].categories, categories(:general)
  end

  def test_eager_with_inheritance
    SpecialPost.all.merge!(includes: [ :comments ]).to_a
  end

  def test_eager_has_one_with_association_inheritance
    post = Post.all.merge!(includes: [ :very_special_comment ]).find(4)
    assert_equal "VerySpecialComment", post.very_special_comment.class.to_s
  end

  def test_eager_has_many_with_association_inheritance
    post = Post.all.merge!(includes: [ :special_comments ]).find(4)
    post.special_comments.each do |special_comment|
      assert special_comment.is_a?(SpecialComment)
    end
  end

  def test_eager_habtm_with_association_inheritance
    post = Post.all.merge!(includes: [ :special_categories ]).find(6)
    assert_equal 1, post.special_categories.size
    post.special_categories.each do |special_category|
      assert_equal "SpecialCategory", special_category.class.to_s
    end
  end

  def test_eager_with_has_one_dependent_does_not_destroy_dependent
    assert_not_nil companies(:first_firm).account
    f = Firm.all.merge!(includes: :account,
            where: ["companies.name = ?", "37signals"]).first
    assert_not_nil f.account
    assert_equal companies(:first_firm, :reload).account, f.account
  end

  def test_eager_with_multi_table_conditional_properly_counts_the_records_when_using_size
    author = authors(:david)
    posts_with_no_comments = author.posts.select { |post| post.comments.blank? }
    assert_equal posts_with_no_comments.size, author.posts_with_no_comments.size
    assert_equal posts_with_no_comments, author.posts_with_no_comments
  end

  def test_eager_with_invalid_association_reference
    e = assert_raise(ActiveRecord::AssociationNotFoundError) {
      Post.all.merge!(includes: :monkeys).find(6)
    }
    assert_equal("Association named 'monkeys' was not found on Post; perhaps you misspelled it?", e.message)

    e = assert_raise(ActiveRecord::AssociationNotFoundError) {
      Post.all.merge!(includes: [ :monkeys ]).find(6)
    }
    assert_equal("Association named 'monkeys' was not found on Post; perhaps you misspelled it?", e.message)

    e = assert_raise(ActiveRecord::AssociationNotFoundError) {
      Post.all.merge!(includes: [ "monkeys" ]).find(6)
    }
    assert_equal("Association named 'monkeys' was not found on Post; perhaps you misspelled it?", e.message)

    e = assert_raise(ActiveRecord::AssociationNotFoundError) {
      Post.all.merge!(includes: [ :monkeys, :elephants ]).find(6)
    }
    assert_equal("Association named 'monkeys' was not found on Post; perhaps you misspelled it?", e.message)
  end

  def test_eager_has_many_through_with_order
    tag = OrderedTag.create(name: "Foo")
    post1 = Post.create!(title: "Beaches", body: "I like beaches!")
    post2 = Post.create!(title: "Pools", body: "I like pools!")

    Tagging.create!(taggable_type: "Post", taggable_id: post1.id, tag: tag)
    Tagging.create!(taggable_type: "Post", taggable_id: post2.id, tag: tag)

    tag_with_includes = OrderedTag.includes(:tagged_posts).find(tag.id)
    assert_equal(tag_with_includes.taggings.map(&:taggable).map(&:title), tag_with_includes.tagged_posts.map(&:title))
  end

  def test_eager_has_many_through_multiple_with_order
    tag1 = OrderedTag.create!(name: "Bar")
    tag2 = OrderedTag.create!(name: "Foo")

    post1 = Post.create!(title: "Beaches", body: "I like beaches!")
    post2 = Post.create!(title: "Pools", body: "I like pools!")

    Tagging.create!(taggable: post1, tag: tag1)
    Tagging.create!(taggable: post2, tag: tag1)
    Tagging.create!(taggable: post2, tag: tag2)
    Tagging.create!(taggable: post1, tag: tag2)

    tags_with_includes = OrderedTag.where(id: [tag1, tag2].map(&:id)).includes(:tagged_posts).order(:id).to_a
    tag1_with_includes = tags_with_includes.first
    tag2_with_includes = tags_with_includes.last

    assert_equal([post2, post1].map(&:title), tag1_with_includes.tagged_posts.map(&:title))
    assert_equal([post1, post2].map(&:title), tag2_with_includes.tagged_posts.map(&:title))
  end

  def test_eager_with_default_scope
    developer = EagerDeveloperWithDefaultScope.where(name: "David").first
    projects = Project.order(:id).to_a
    assert_no_queries do
      assert_equal(projects, developer.projects)
    end
  end

  def test_eager_with_default_scope_as_class_method
    developer = EagerDeveloperWithClassMethodDefaultScope.where(name: "David").first
    projects = Project.order(:id).to_a
    assert_no_queries do
      assert_equal(projects, developer.projects)
    end
  end

  def test_eager_with_default_scope_as_class_method_using_find_method
    david = developers(:david)
    developer = EagerDeveloperWithClassMethodDefaultScope.find(david.id)
    projects = Project.order(:id).to_a
    assert_no_queries do
      assert_equal(projects, developer.projects)
    end
  end

  def test_eager_with_default_scope_as_class_method_using_find_by_method
    developer = EagerDeveloperWithClassMethodDefaultScope.find_by(name: "David")
    projects = Project.order(:id).to_a
    assert_no_queries do
      assert_equal(projects, developer.projects)
    end
  end

  def test_eager_with_default_scope_as_lambda
    developer = EagerDeveloperWithLambdaDefaultScope.where(name: "David").first
    projects = Project.order(:id).to_a
    assert_no_queries do
      assert_equal(projects, developer.projects)
    end
  end

  def test_eager_with_default_scope_as_block
    # warm up the habtm cache
    EagerDeveloperWithBlockDefaultScope.where(name: "David").first.projects
    developer = EagerDeveloperWithBlockDefaultScope.where(name: "David").first
    projects = Project.order(:id).to_a
    assert_no_queries do
      assert_equal(projects, developer.projects)
    end
  end

  def test_eager_with_default_scope_as_callable
    developer = EagerDeveloperWithCallableDefaultScope.where(name: "David").first
    projects = Project.order(:id).to_a
    assert_no_queries do
      assert_equal(projects, developer.projects)
    end
  end

  def find_all_ordered(className, include = nil)
    className.all.merge!(order: "#{className.table_name}.#{className.primary_key}", includes: include).to_a
  end

  def test_limited_eager_with_order
    assert_equal(
      posts(:thinking, :sti_comments),
      Post.all.merge!(
        includes: [:author, :comments], where: { "authors.name" => "David" },
        order: "UPPER(posts.title)", limit: 2, offset: 1
      ).to_a
    )
    assert_equal(
      posts(:sti_post_and_comments, :sti_comments),
      Post.all.merge!(
        includes: [:author, :comments], where: { "authors.name" => "David" },
        order: "UPPER(posts.title) DESC", limit: 2, offset: 1
      ).to_a
    )
  end

  def test_limited_eager_with_multiple_order_columns
    assert_equal(
      posts(:thinking, :sti_comments),
      Post.all.merge!(
        includes: [:author, :comments], where: { "authors.name" => "David" },
        order: ["UPPER(posts.title)", "posts.id"], limit: 2, offset: 1
      ).to_a
    )
    assert_equal(
      posts(:sti_post_and_comments, :sti_comments),
      Post.all.merge!(
        includes: [:author, :comments], where: { "authors.name" => "David" },
        order: ["UPPER(posts.title) DESC", "posts.id"], limit: 2, offset: 1
      ).to_a
    )
  end

  def test_limited_eager_with_numeric_in_association
    assert_equal(
      people(:david, :susan),
      Person.references(:number1_fans_people).merge(
        includes: [:readers, :primary_contact, :number1_fan],
        where: "number1_fans_people.first_name like 'M%'",
        order: "people.id", limit: 2, offset: 0
      ).to_a
    )
  end

  def test_polymorphic_type_condition
    post = Post.all.merge!(includes: :taggings).find(posts(:thinking).id)
    assert_includes post.taggings, taggings(:thinking_general)
    post = SpecialPost.all.merge!(includes: :taggings).find(posts(:thinking).id)
    assert_includes post.taggings, taggings(:thinking_general)
  end

  def test_eager_with_multiple_associations_with_same_table_has_many_and_habtm
    # Eager includes of has many and habtm associations aren't necessarily sorted in the same way
    def assert_equal_after_sort(item1, item2, item3 = nil)
      assert_equal(item1.sort { |a, b| a.id <=> b.id }, item2.sort { |a, b| a.id <=> b.id })
      assert_equal(item3.sort { |a, b| a.id <=> b.id }, item2.sort { |a, b| a.id <=> b.id }) if item3
    end
    # Test regular association, association with conditions, association with
    # STI, and association with conditions assured not to be true
    post_types = [:posts, :other_posts, :special_posts]
    # test both has_many and has_and_belongs_to_many
    [Author, Category].each do |className|
      d1 = find_all_ordered(className)
      # test including all post types at once
      d2 = find_all_ordered(className, post_types)
      d1.each_index do |i|
        assert_equal(d1[i], d2[i])
        assert_equal_after_sort(d1[i].posts, d2[i].posts)
        post_types[1..-1].each do |post_type|
          # test including post_types together
          d3 = find_all_ordered(className, [:posts, post_type])
          assert_equal(d1[i], d3[i])
          assert_equal_after_sort(d1[i].posts, d3[i].posts)
          assert_equal_after_sort(d1[i].send(post_type), d2[i].send(post_type), d3[i].send(post_type))
        end
      end
    end
  end

  def test_eager_with_multiple_associations_with_same_table_has_one
    d1 = find_all_ordered(Firm)
    d2 = find_all_ordered(Firm, :account)
    d1.each_index do |i|
      assert_equal(d1[i], d2[i])
      if d1[i].account.nil?
        assert_nil(d2[i].account)
      else
        assert_equal(d1[i].account, d2[i].account)
      end
    end
  end

  def test_eager_with_multiple_associations_with_same_table_belongs_to
    firm_types = [:firm, :firm_with_basic_id, :firm_with_other_name, :firm_with_condition]
    d1 = find_all_ordered(Client)
    d2 = find_all_ordered(Client, firm_types)
    d1.each_index do |i|
      assert_equal(d1[i], d2[i])
      firm_types.each do |type|
        if (expected = d1[i].send(type)).nil?
          assert_nil(d2[i].send(type))
        else
          assert_equal(expected, d2[i].send(type))
        end
      end
    end
  end
  def test_eager_with_valid_association_as_string_not_symbol
    assert_nothing_raised { Post.all.merge!(includes: "comments").to_a }
  end

  def test_eager_with_floating_point_numbers
    assert_queries(2) do
      # Before changes, the floating point numbers will be interpreted as table names and will cause this to run in one query
      Comment.all.merge!(where: "123.456 = 123.456", includes: :post).to_a
    end
  end

  def test_preconfigured_includes_with_belongs_to
    author = posts(:welcome).author_with_posts
    assert_no_queries { assert_equal 5, author.posts.size }
  end

  def test_preconfigured_includes_with_has_one
    comment = posts(:sti_comments).very_special_comment_with_post
    assert_no_queries { assert_equal posts(:sti_comments), comment.post }
  end

  def test_eager_association_with_scope_with_joins
    assert_nothing_raised do
      Post.includes(:very_special_comment_with_post_with_joins).to_a
    end
  end

  def test_preconfigured_includes_with_has_many
    posts = authors(:david).posts_with_comments
    one = posts.detect { |p| p.id == 1 }
    assert_no_queries do
      assert_equal 5, posts.size
      assert_equal 2, one.comments.size
    end
  end

  def test_preconfigured_includes_with_habtm
    posts = authors(:david).posts_with_categories
    one = posts.detect { |p| p.id == 1 }
    assert_no_queries do
      assert_equal 5, posts.size
      assert_equal 2, one.categories.size
    end
  end

  def test_preconfigured_includes_with_has_many_and_habtm
    posts = authors(:david).posts_with_comments_and_categories
    one = posts.detect { |p| p.id == 1 }
    assert_no_queries do
      assert_equal 5, posts.size
      assert_equal 2, one.comments.size
      assert_equal 2, one.categories.size
    end
  end

  def test_count_with_include
    assert_equal 3, authors(:david).posts_with_comments.where("length(comments.body) > 15").references(:comments).count
  end

  def test_association_loading_notification
    notifications = messages_for("instantiation.active_record") do
      Developer.all.merge!(includes: "projects", where: { "developers_projects.access_level" => 1 }, limit: 5).to_a.size
    end

    message = notifications.first
    payload = message.last
    count = Developer.all.merge!(includes: "projects", where: { "developers_projects.access_level" => 1 }, limit: 5).to_a.size

    # eagerloaded row count should be greater than just developer count
    assert_operator payload[:record_count], :>, count
    assert_equal Developer.name, payload[:class_name]
  end

  def test_base_messages
    notifications = messages_for("instantiation.active_record") do
      Developer.all.to_a
    end
    message = notifications.first
    payload = message.last

    assert_equal Developer.all.to_a.count, payload[:record_count]
    assert_equal Developer.name, payload[:class_name]
  end

  def messages_for(name)
    notifications = []
    ActiveSupport::Notifications.subscribe(name) do |*args|
      notifications << args
    end
    yield
    notifications
  ensure
    ActiveSupport::Notifications.unsubscribe(name)
  end

  def test_load_with_sti_sharing_association
    assert_queries(2) do #should not do 1 query per subclass
      Comment.includes(:post).to_a
    end
  end

  def test_conditions_on_join_table_with_include_and_limit
    assert_equal 3, Developer.all.merge!(includes: "projects", where: { "developers_projects.access_level" => 1 }, limit: 5).to_a.size
  end

  def test_dont_create_temporary_active_record_instances
    Developer.instance_count = 0
    developers = Developer.all.merge!(includes: "projects", where: { "developers_projects.access_level" => 1 }, limit: 5).to_a
    assert_equal developers.count, Developer.instance_count
  end

  def test_order_on_join_table_with_include_and_limit
    assert_equal 5, Developer.all.merge!(includes: "projects", order: "developers_projects.joined_on DESC", limit: 5).to_a.size
  end

  def test_eager_loading_with_order_on_joined_table_preloads
    posts = assert_queries(2) do
      Post.all.merge!(joins: :comments, includes: :author, order: "comments.id DESC").to_a
    end
    assert_equal posts(:eager_other), posts[1]
    assert_equal authors(:mary), assert_no_queries { posts[1].author }
  end

  def test_eager_loading_with_conditions_on_joined_table_preloads
    posts = assert_queries(2) do
      Post.all.merge!(select: "distinct posts.*", includes: :author, joins: [:comments], where: "comments.body like 'Thank you%'", order: "posts.id").to_a
    end
    assert_equal [posts(:welcome)], posts
    assert_equal authors(:david), assert_no_queries { posts[0].author }

    posts = assert_queries(2) do
      Post.all.merge!(includes: :author, joins: { taggings: :tag }, where: "tags.name = 'General'", order: "posts.id").to_a
    end
    assert_equal posts(:welcome, :thinking), posts

    posts = assert_queries(2) do
      Post.all.merge!(includes: :author, joins: { taggings: { tag: :taggings } }, where: "taggings_tags.super_tag_id=2", order: "posts.id").to_a
    end
    assert_equal posts(:welcome, :thinking), posts
  end

  def test_preload_has_many_with_association_condition_and_default_scope
    post = Post.create!(title: "Beaches", body: "I like beaches!")
    Reader.create! person: people(:david), post: post
    LazyReader.create! person: people(:susan), post: post

    assert_equal 1, post.lazy_readers.to_a.size
    assert_equal 2, post.lazy_readers_skimmers_or_not.to_a.size

    post_with_readers = Post.includes(:lazy_readers_skimmers_or_not).find(post.id)
    assert_equal 2, post_with_readers.lazy_readers_skimmers_or_not.to_a.size
  end

  def test_eager_loading_with_conditions_on_string_joined_table_preloads
    posts = assert_queries(2) do
      Post.all.merge!(select: "distinct posts.*", includes: :author, joins: "INNER JOIN comments on comments.post_id = posts.id", where: "comments.body like 'Thank you%'", order: "posts.id").to_a
    end
    assert_equal [posts(:welcome)], posts
    assert_equal authors(:david), assert_no_queries { posts[0].author }

    posts = assert_queries(2) do
      Post.all.merge!(select: "distinct posts.*", includes: :author, joins: ["INNER JOIN comments on comments.post_id = posts.id"], where: "comments.body like 'Thank you%'", order: "posts.id").to_a
    end
    assert_equal [posts(:welcome)], posts
    assert_equal authors(:david), assert_no_queries { posts[0].author }
  end

  def test_eager_loading_with_select_on_joined_table_preloads
    posts = assert_queries(2) do
      Post.all.merge!(select: "posts.*, authors.name as author_name", includes: :comments, joins: :author, order: "posts.id").to_a
    end
    assert_equal "David", posts[0].author_name
    assert_equal posts(:welcome).comments, assert_no_queries { posts[0].comments }
  end

  def test_eager_loading_with_conditions_on_join_model_preloads
    authors = assert_queries(2) do
      Author.all.merge!(includes: :author_address, joins: :comments, where: "posts.title like 'Welcome%'").to_a
    end
    assert_equal authors(:david), authors[0]
    assert_equal author_addresses(:david_address), authors[0].author_address
  end

  def test_preload_belongs_to_uses_exclusive_scope
    people = Person.males.merge(includes: :primary_contact).to_a
    assert_not_equal people.length, 0
    people.each do |person|
      assert_no_queries { assert_not_nil person.primary_contact }
      assert_equal Person.find(person.id).primary_contact, person.primary_contact
    end
  end

  def test_preload_has_many_uses_exclusive_scope
    people = Person.males.includes(:agents).to_a
    people.each do |person|
      assert_equal Person.find(person.id).agents, person.agents
    end
  end

  def test_preload_has_many_using_primary_key
    expected = Firm.first.clients_using_primary_key.to_a
    firm = Firm.includes(:clients_using_primary_key).first
    assert_no_queries do
      assert_equal expected, firm.clients_using_primary_key
    end
  end

  def test_include_has_many_using_primary_key
    expected = Firm.find(1).clients_using_primary_key.sort_by(&:name)
    # Oracle adapter truncates alias to 30 characters
    if current_adapter?(:OracleAdapter)
      firm = Firm.all.merge!(includes: :clients_using_primary_key, order: "clients_using_primary_keys_companies"[0, 30] + ".name").find(1)
    else
      firm = Firm.all.merge!(includes: :clients_using_primary_key, order: "clients_using_primary_keys_companies.name").find(1)
    end
    assert_no_queries do
      assert_equal expected, firm.clients_using_primary_key
    end
  end

  def test_preload_has_one_using_primary_key
    expected = accounts(:signals37)
    firm = Firm.all.merge!(includes: :account_using_primary_key, order: "companies.id").first
    assert_no_queries do
      assert_equal expected, firm.account_using_primary_key
    end
  end

  def test_include_has_one_using_primary_key
    expected = accounts(:signals37)
    firm = Firm.all.merge!(includes: :account_using_primary_key, order: "accounts.id").to_a.detect { |f| f.id == 1 }
    assert_no_queries do
      assert_equal expected, firm.account_using_primary_key
    end
  end

  def test_preloading_empty_belongs_to
    c = Client.create!(name: "Foo", client_of: Company.maximum(:id) + 1)

    client = assert_queries(2) { Client.preload(:firm).find(c.id) }
    assert_no_queries { assert_nil client.firm }
  end

  def test_preloading_empty_belongs_to_polymorphic
    t = Tagging.create!(taggable_type: "Post", taggable_id: Post.maximum(:id) + 1, tag: tags(:general))

    tagging = assert_queries(2) { Tagging.preload(:taggable).find(t.id) }
    assert_no_queries { assert_nil tagging.taggable }
  end

  def test_preloading_through_empty_belongs_to
    c = Client.create!(name: "Foo", client_of: Company.maximum(:id) + 1)

    client = assert_queries(2) { Client.preload(:accounts).find(c.id) }
    assert_no_queries { assert client.accounts.empty? }
  end

  def test_preloading_has_many_through_with_distinct
    mary = Author.includes(:unique_categorized_posts).where(id: authors(:mary).id).first
    assert_equal 1, mary.unique_categorized_posts.length
    assert_equal 1, mary.unique_categorized_post_ids.length
  end

  def test_preloading_has_one_using_reorder
    klass = Class.new(ActiveRecord::Base) do
      def self.name; "TempAuthor"; end
      self.table_name = "authors"
      has_one :post, class_name: "PostWithDefaultScope", foreign_key: :author_id
      has_one :reorderd_post, -> { reorder(title: :desc) }, class_name: "PostWithDefaultScope", foreign_key: :author_id
    end

    author = klass.first
    # PRECONDITION: make sure ordering results in different results
    assert_not_equal author.post, author.reorderd_post

    preloaded_reorderd_post = klass.preload(:reorderd_post).first.reorderd_post

    assert_equal author.reorderd_post, preloaded_reorderd_post
    assert_equal Post.order(title: :desc).first.title, preloaded_reorderd_post.title
  end

  def test_preloading_polymorphic_with_custom_foreign_type
    sponsor = sponsors(:moustache_club_sponsor_for_groucho)
    groucho = members(:groucho)

    sponsor = assert_queries(2) {
      Sponsor.includes(:thing).where(id: sponsor.id).first
    }
    assert_no_queries { assert_equal groucho, sponsor.thing }
  end

  def test_joins_with_includes_should_preload_via_joins
    post = assert_queries(1) { Post.includes(:comments).joins(:comments).order("posts.id desc").to_a.first }

    assert_queries(0) do
      assert_not_equal 0, post.comments.to_a.count
    end
  end

  def test_join_eager_with_empty_order_should_generate_valid_sql
    assert_nothing_raised do
      Post.includes(:comments).order("").where(comments: { body: "Thank you for the welcome" }).first
    end
  end

  def test_deep_including_through_habtm
    # warm up habtm cache
    posts = Post.all.merge!(includes: { categories: :categorizations }, order: "posts.id").to_a
    posts[0].categories[0].categorizations.length

    posts = Post.all.merge!(includes: { categories: :categorizations }, order: "posts.id").to_a
    assert_no_queries { assert_equal 2, posts[0].categories[0].categorizations.length }
    assert_no_queries { assert_equal 1, posts[0].categories[1].categorizations.length }
    assert_no_queries { assert_equal 2, posts[1].categories[0].categorizations.length }
  end

  def test_eager_load_multiple_associations_with_references
    mentor = Mentor.create!(name: "Barış Can DAYLIK")
    developer = Developer.create!(name: "Mehmet Emin İNAÇ", mentor: mentor)
    Contract.create!(developer: developer)
    project = Project.create!(name: "VNGRS", mentor: mentor)
    project.developers << developer
    projects = Project.references(:mentors).includes(mentor: { developers: :contracts }, developers: :contracts)
    assert_equal projects.last.mentor.developers.first.contracts, projects.last.developers.last.contracts
  end

  test "scoping with a circular preload" do
    assert_equal Comment.find(1), Comment.preload(post: :comments).scoping { Comment.find(1) }
  end

  test "circular preload does not modify unscoped" do
    expected = FirstPost.unscoped.find(2)
    FirstPost.preload(comments: :first_post).find(1)
    assert_equal expected, FirstPost.unscoped.find(2)
  end

  test "preload ignores the scoping" do
    assert_equal(
      Comment.find(1).post,
      Post.where("1 = 0").scoping { Comment.preload(:post).find(1).post }
    )
  end

  test "deep preload" do
    post = Post.preload(author: :posts, comments: :post).first

    assert_predicate post.author.association(:posts), :loaded?
    assert_predicate post.comments.first.association(:post), :loaded?
  end

  test "preloading does not cache has many association subset when preloaded with a through association" do
    author = Author.includes(:comments_with_order_and_conditions, :posts).first
    assert_no_queries { assert_equal 2, author.comments_with_order_and_conditions.size }
    assert_no_queries { assert_equal 5, author.posts.size, "should not cache a subset of the association" }
  end

  test "preloading a through association twice does not reset it" do
    members = Member.includes(current_membership: :club).includes(:club).to_a
    assert_no_queries {
      assert_equal 3, members.map(&:current_membership).map(&:club).size
    }
  end

  test "works in combination with order(:symbol) and reorder(:symbol)" do
    author = Author.includes(:posts).references(:posts).order(:name).find_by("posts.title IS NOT NULL")
    assert_equal authors(:bob), author

    author = Author.includes(:posts).references(:posts).reorder(:name).find_by("posts.title IS NOT NULL")
    assert_equal authors(:bob), author
  end

  test "preloading with a polymorphic association and using the existential predicate but also using a select" do
    assert_equal authors(:david), authors(:david).essays.includes(:writer).first.writer

    assert_nothing_raised do
      authors(:david).essays.includes(:writer).select(:name).any?
    end
  end

  test "preloading the same association twice works" do
    Member.create!
    members = Member.preload(:current_membership).includes(current_membership: :club).all.to_a
    assert_no_queries {
      members_with_membership = members.select(&:current_membership)
      assert_equal 3, members_with_membership.map(&:current_membership).map(&:club).size
    }
  end

  test "preloading with a polymorphic association and using the existential predicate" do
    assert_equal authors(:david), authors(:david).essays.includes(:writer).first.writer

    assert_nothing_raised do
      authors(:david).essays.includes(:writer).any?
      authors(:david).essays.includes(:writer).exists?
      authors(:david).essays.includes(:owner).where("name IS NOT NULL").exists?
    end
  end

  test "preloading associations with string joins and order references" do
    author = assert_queries(2) {
      Author.includes(:posts).joins("LEFT JOIN posts ON posts.author_id = authors.id").order("posts.title DESC").first
    }
    assert_no_queries {
      assert_equal 5, author.posts.size
    }
  end

  test "including associations with where.not adds implicit references" do
    author = assert_queries(2) {
      Author.includes(:posts).where.not(posts: { title: "Welcome to the weblog" }).last
    }

    assert_no_queries {
      assert_equal 2, author.posts.size
    }
  end

  test "including association based on sql condition and no database column" do
    assert_equal pets(:parrot), Owner.including_last_pet.first.last_pet
  end

  test "preloading and eager loading of instance dependent associations is not supported" do
    message = "association scope 'posts_with_signature' is"
    error = assert_raises(ArgumentError) do
      Author.includes(:posts_with_signature).to_a
    end
    assert_match message, error.message

    error = assert_raises(ArgumentError) do
      Author.preload(:posts_with_signature).to_a
    end
    assert_match message, error.message

    error = assert_raises(ArgumentError) do
      Author.eager_load(:posts_with_signature).to_a
    end
    assert_match message, error.message
  end

  test "preload with invalid argument" do
    exception = assert_raises(ArgumentError) do
      Author.preload(10).to_a
    end
    assert_equal("10 was not recognized for preload", exception.message)
  end

  test "associations with extensions are not instance dependent" do
    assert_nothing_raised do
      Author.includes(:posts_with_extension).to_a
    end
  end

  test "including associations with extensions and an instance dependent scope is not supported" do
    e = assert_raises(ArgumentError) do
      Author.includes(:posts_with_extension_and_instance).to_a
    end
    assert_match(/Preloading instance dependent scopes is not supported/, e.message)
  end

  test "preloading readonly association" do
    # has-one
    firm = Firm.where(id: "1").preload(:readonly_account).first!
    assert firm.readonly_account.readonly?

    # has_and_belongs_to_many
    project = Project.where(id: "2").preload(:readonly_developers).first!
    assert project.readonly_developers.first.readonly?

    # has-many :through
    david = Author.where(id: "1").preload(:readonly_comments).first!
    assert david.readonly_comments.first.readonly?
  end

  test "eager-loading non-readonly association" do
    # has_one
    firm = Firm.where(id: "1").eager_load(:account).first!
    assert_not firm.account.readonly?

    # has_and_belongs_to_many
    project = Project.where(id: "2").eager_load(:developers).first!
    assert_not project.developers.first.readonly?

    # has_many :through
    david = Author.where(id: "1").eager_load(:comments).first!
    assert_not david.comments.first.readonly?

    # belongs_to
    post = Post.where(id: "1").eager_load(:author).first!
    assert_not post.author.readonly?
  end

  test "eager-loading readonly association" do
    # has-one
    firm = Firm.where(id: "1").eager_load(:readonly_account).first!
    assert firm.readonly_account.readonly?

    # has_and_belongs_to_many
    project = Project.where(id: "2").eager_load(:readonly_developers).first!
    assert project.readonly_developers.first.readonly?

    # has-many :through
    david = Author.where(id: "1").eager_load(:readonly_comments).first!
    assert david.readonly_comments.first.readonly?

    # belongs_to
    post = Post.where(id: "1").eager_load(:readonly_author).first!
    assert post.readonly_author.readonly?
  end

  test "preloading a polymorphic association with references to the associated table" do
    post = Post.includes(:tags).references(:tags).where("tags.name = ?", "General").first
    assert_equal posts(:welcome), post
  end

  test "eager-loading a polymorphic association with references to the associated table" do
    post = Post.eager_load(:tags).where("tags.name = ?", "General").first
    assert_equal posts(:welcome), post
  end

  # CollectionProxy#reader is expensive, so the preloader avoids calling it.
  test "preloading has_many_through association avoids calling association.reader" do
    ActiveRecord::Associations::HasManyAssociation.any_instance.expects(:reader).never
    Author.preload(:readonly_comments).first!
  end
end