rails--rails/activerecord/test/cases/associations_test.rb

# frozen_string_literal: true

require "cases/helper"
require "models/computer"
require "models/developer"
require "models/project"
require "models/company"
require "models/categorization"
require "models/category"
require "models/post"
require "models/author"
require "models/book"
require "models/comment"
require "models/tag"
require "models/tagging"
require "models/person"
require "models/reader"
require "models/ship_part"
require "models/ship"
require "models/liquid"
require "models/molecule"
require "models/electron"
require "models/human"
require "models/interest"
require "models/pirate"
require "models/parrot"
require "models/bird"
require "models/treasure"
require "models/price_estimate"
require "models/invoice"
require "models/discount"
require "models/line_item"
require "models/shipping_line"
require "models/essay"

class AssociationsTest < ActiveRecord::TestCase
  fixtures :accounts, :companies, :developers, :projects, :developers_projects,
           :computers, :people, :readers, :authors, :author_addresses, :author_favorites,
           :comments, :posts

  def test_eager_loading_should_not_change_count_of_children
    liquid = Liquid.create(name: "salty")
    molecule = liquid.molecules.create(name: "molecule_1")
    molecule.electrons.create(name: "electron_1")
    molecule.electrons.create(name: "electron_2")

    liquids = Liquid.includes(molecules: :electrons).references(:molecules).where("molecules.id is not null")
    assert_equal 1, liquids[0].molecules.length
  end

  def test_subselect
    author = authors :david
    favs = author.author_favorites
    fav2 = author.author_favorites.where(author: Author.where(id: author.id)).to_a
    assert_equal favs, fav2
  end

  def test_loading_the_association_target_should_keep_child_records_marked_for_destruction
    ship = Ship.create!(name: "The good ship Dollypop")
    part = ship.parts.create!(name: "Mast")
    part.mark_for_destruction
    assert_predicate ship.parts[0], :marked_for_destruction?
  end

  def test_loading_the_association_target_should_load_most_recent_attributes_for_child_records_marked_for_destruction
    ship = Ship.create!(name: "The good ship Dollypop")
    part = ship.parts.create!(name: "Mast")
    part.mark_for_destruction
    ShipPart.find(part.id).update_columns(name: "Deck")
    assert_equal "Deck", ship.parts[0].name
  end

  def test_include_with_order_works
    assert_nothing_raised { Account.all.merge!(order: "id", includes: :firm).first }
    assert_nothing_raised { Account.all.merge!(order: :id, includes: :firm).first }
  end

  def test_bad_collection_keys
    assert_raise(ArgumentError, "ActiveRecord should have barked on bad collection keys") do
      Class.new(ActiveRecord::Base).has_many(:wheels, name: "wheels")
    end
  end

  def test_should_construct_new_finder_sql_after_create
    person = Person.new first_name: "clark"
    assert_equal [], person.readers.to_a
    person.save!
    reader = Reader.create! person: person, post: Post.new(title: "foo", body: "bar")
    assert person.readers.find(reader.id)
  end

  def test_force_reload
    firm = Firm.new("name" => "A New Firm, Inc")
    firm.save
    firm.clients.each { } # forcing to load all clients
    assert firm.clients.empty?, "New firm shouldn't have client objects"
    assert_equal 0, firm.clients.size, "New firm should have 0 clients"

    client = Client.new("name" => "TheClient.com", "firm_id" => firm.id)
    client.save

    assert firm.clients.empty?, "New firm should have cached no client objects"
    assert_equal 0, firm.clients.size, "New firm should have cached 0 clients count"

    firm.clients.reload

    assert_not firm.clients.empty?, "New firm should have reloaded client objects"
    assert_equal 1, firm.clients.size, "New firm should have reloaded clients count"
  end

  def test_using_limitable_reflections_helper
    using_limitable_reflections = lambda { |reflections| Tagging.all.send :using_limitable_reflections?, reflections }
    belongs_to_reflections = [Tagging.reflect_on_association(:tag), Tagging.reflect_on_association(:super_tag)]
    has_many_reflections = [Tag.reflect_on_association(:taggings), Developer.reflect_on_association(:projects)]
    mixed_reflections = (belongs_to_reflections + has_many_reflections).uniq
    assert using_limitable_reflections.call(belongs_to_reflections), "Belong to associations are limitable"
    assert_not using_limitable_reflections.call(has_many_reflections), "All has many style associations are not limitable"
    assert_not using_limitable_reflections.call(mixed_reflections), "No collection associations (has many style) should pass"
  end

  def test_association_with_references
    firm = companies(:first_firm)
    assert_equal [:foo], firm.association_with_references.references_values
  end
end

class AssociationProxyTest < ActiveRecord::TestCase
  fixtures :authors, :author_addresses, :posts, :categorizations, :categories, :developers, :projects, :developers_projects

  def test_push_does_not_load_target
    david = authors(:david)

    david.posts << (post = Post.new(title: "New on Edge", body: "More cool stuff!"))
    assert_not_predicate david.posts, :loaded?
    assert_includes david.posts, post
  end

  def test_push_has_many_through_does_not_load_target
    david = authors(:david)

    david.categories << categories(:technology)
    assert_not_predicate david.categories, :loaded?
    assert_includes david.categories, categories(:technology)
  end

  def test_push_followed_by_save_does_not_load_target
    david = authors(:david)

    david.posts << (post = Post.new(title: "New on Edge", body: "More cool stuff!"))
    assert_not_predicate david.posts, :loaded?
    david.save
    assert_not_predicate david.posts, :loaded?
    assert_includes david.posts, post
  end

  def test_push_does_not_lose_additions_to_new_record
    josh = Author.new(name: "Josh")
    josh.posts << Post.new(title: "New on Edge", body: "More cool stuff!")
    assert_predicate josh.posts, :loaded?
    assert_equal 1, josh.posts.size
  end

  def test_append_behaves_like_push
    josh = Author.new(name: "Josh")
    josh.posts.append Post.new(title: "New on Edge", body: "More cool stuff!")
    assert_predicate josh.posts, :loaded?
    assert_equal 1, josh.posts.size
  end

  def test_prepend_is_not_defined
    josh = Author.new(name: "Josh")
    assert_raises(NoMethodError) { josh.posts.prepend Post.new }
  end

  def test_save_on_parent_does_not_load_target
    david = developers(:david)

    assert_not_predicate david.projects, :loaded?
    david.update_columns(created_at: Time.now)
    assert_not_predicate david.projects, :loaded?
  end

  def test_load_does_load_target
    david = developers(:david)

    assert_not_predicate david.projects, :loaded?
    david.projects.load
    assert_predicate david.projects, :loaded?
  end

  def test_inspect_does_not_reload_a_not_yet_loaded_target
    andreas = Developer.new name: "Andreas", log: "new developer added"
    assert_not_predicate andreas.audit_logs, :loaded?
    assert_match(/message: "new developer added"/, andreas.audit_logs.inspect)
    assert_predicate andreas.audit_logs, :loaded?
  end

  def test_save_on_parent_saves_children
    developer = Developer.create name: "Bryan", salary: 50_000
    assert_equal 1, developer.reload.audit_logs.size
  end

  def test_create_via_association_with_block
    post = authors(:david).posts.create(title: "New on Edge") { |p| p.body = "More cool stuff!" }
    assert_equal post.title, "New on Edge"
    assert_equal post.body, "More cool stuff!"
  end

  def test_create_with_bang_via_association_with_block
    post = authors(:david).posts.create!(title: "New on Edge") { |p| p.body = "More cool stuff!" }
    assert_equal post.title, "New on Edge"
    assert_equal post.body, "More cool stuff!"
  end

  def test_reload_returns_association
    david = developers(:david)
    assert_nothing_raised do
      assert_equal david.projects, david.projects.reload.reload
    end
  end

  def test_proxy_association_accessor
    david = developers(:david)
    assert_equal david.association(:projects), david.projects.proxy_association
  end

  def test_scoped_allows_conditions
    assert developers(:david).projects.merge(where: "foo").to_sql.include?("foo")
  end

  test "getting a scope from an association" do
    david = developers(:david)

    assert david.projects.scope.is_a?(ActiveRecord::Relation)
    assert_equal david.projects, david.projects.scope
  end

  test "proxy object is cached" do
    david = developers(:david)
    assert_same david.projects, david.projects
  end

  test "proxy object can be stubbed" do
    david = developers(:david)
    david.projects.define_singleton_method(:extra_method) { 42 }

    assert_equal 42, david.projects.extra_method
  end

  test "inverses get set of subsets of the association" do
    human = Human.create
    human.interests.create

    human = Human.find(human.id)

    assert_queries(1) do
      assert_equal human, human.interests.where("1=1").first.human
    end
  end

  test "first! works on loaded associations" do
    david = authors(:david)
    assert_equal david.first_posts.first, david.first_posts.reload.first!
    assert_predicate david.first_posts, :loaded?
    assert_no_queries { david.first_posts.first! }
  end

  def test_pluck_uses_loaded_target
    david = authors(:david)
    assert_equal david.first_posts.pluck(:title), david.first_posts.load.pluck(:title)
    assert_predicate david.first_posts, :loaded?
    assert_no_queries { david.first_posts.pluck(:title) }
  end

  def test_pick_uses_loaded_target
    david = authors(:david)
    assert_equal david.first_posts.pick(:title), david.first_posts.load.pick(:title)
    assert_predicate david.first_posts, :loaded?
    assert_no_queries { david.first_posts.pick(:title) }
  end

  def test_reset_unloads_target
    david = authors(:david)
    david.posts.reload

    assert_predicate david.posts, :loaded?
    assert_predicate david.posts, :loaded
    david.posts.reset
    assert_not_predicate david.posts, :loaded?
    assert_not_predicate david.posts, :loaded
  end

  def test_target_merging_ignores_persisted_in_memory_records
    david = authors(:david)
    assert david.thinking_posts.include?(posts(:thinking))

    david.thinking_posts.create!(title: "Something else entirely", body: "Does not matter.")

    assert_equal 1, david.thinking_posts.size
    assert_equal 1, david.thinking_posts.to_a.size
  end
end

class OverridingAssociationsTest < ActiveRecord::TestCase
  class DifferentPerson < ActiveRecord::Base; end

  class PeopleList < ActiveRecord::Base
    has_and_belongs_to_many :has_and_belongs_to_many, before_add: :enlist
    has_many :has_many, before_add: :enlist
    belongs_to :belongs_to
    has_one :has_one
  end

  class DifferentPeopleList < PeopleList
    # Different association with the same name, callbacks should be omitted here.
    has_and_belongs_to_many :has_and_belongs_to_many, class_name: "DifferentPerson"
    has_many :has_many, class_name: "DifferentPerson"
    belongs_to :belongs_to, class_name: "DifferentPerson"
    has_one :has_one, class_name: "DifferentPerson"
  end

  def test_habtm_association_redefinition_callbacks_should_differ_and_not_inherited
    # redeclared association on AR descendant should not inherit callbacks from superclass
    callbacks = PeopleList.before_add_for_has_and_belongs_to_many
    assert_equal(1, callbacks.length)
    callbacks = DifferentPeopleList.before_add_for_has_and_belongs_to_many
    assert_equal([], callbacks)
  end

  def test_has_many_association_redefinition_callbacks_should_differ_and_not_inherited
    # redeclared association on AR descendant should not inherit callbacks from superclass
    callbacks = PeopleList.before_add_for_has_many
    assert_equal(1, callbacks.length)
    callbacks = DifferentPeopleList.before_add_for_has_many
    assert_equal([], callbacks)
  end

  def test_habtm_association_redefinition_reflections_should_differ_and_not_inherited
    assert_not_equal(
      PeopleList.reflect_on_association(:has_and_belongs_to_many),
      DifferentPeopleList.reflect_on_association(:has_and_belongs_to_many)
    )
  end

  def test_has_many_association_redefinition_reflections_should_differ_and_not_inherited
    assert_not_equal(
      PeopleList.reflect_on_association(:has_many),
      DifferentPeopleList.reflect_on_association(:has_many)
    )
  end

  def test_belongs_to_association_redefinition_reflections_should_differ_and_not_inherited
    assert_not_equal(
      PeopleList.reflect_on_association(:belongs_to),
      DifferentPeopleList.reflect_on_association(:belongs_to)
    )
  end

  def test_has_one_association_redefinition_reflections_should_differ_and_not_inherited
    assert_not_equal(
      PeopleList.reflect_on_association(:has_one),
      DifferentPeopleList.reflect_on_association(:has_one)
    )
  end

  def test_requires_symbol_argument
    assert_raises ArgumentError do
      Class.new(Post) do
        belongs_to "author"
      end
    end
  end

  class ModelAssociatedToClassesThatDoNotExist < ActiveRecord::Base
    self.table_name = "accounts" # this is just to avoid adding a new model just for this test

    has_one :non_existent_has_one_class
    belongs_to :non_existent_belongs_to_class
    has_many :non_existent_has_many_classes
  end

  def test_associations_raise_with_name_error_if_associated_to_classes_that_do_not_exist
    assert_raises NameError do
      ModelAssociatedToClassesThatDoNotExist.new.non_existent_has_one_class
    end

    assert_raises NameError do
      ModelAssociatedToClassesThatDoNotExist.new.non_existent_belongs_to_class
    end

    assert_raises NameError do
      ModelAssociatedToClassesThatDoNotExist.new.non_existent_has_many_classes
    end
  end
end

class PreloaderTest < ActiveRecord::TestCase
  fixtures :posts, :comments, :books, :authors, :tags, :taggings, :essays, :categories, :author_addresses

  def test_preload_with_scope
    post = posts(:welcome)

    preloader = ActiveRecord::Associations::Preloader.new(records: [post], associations: :comments, scope: Comment.where(body: "Thank you for the welcome"))
    preloader.call

    assert_predicate post.comments, :loaded?
    assert_equal [comments(:greetings)], post.comments
  end

  def test_preload_makes_correct_number_of_queries_on_array
    post = posts(:welcome)

    assert_queries(1) do
      preloader = ActiveRecord::Associations::Preloader.new(records: [post], associations: :comments)
      preloader.call
    end
  end

  def test_preload_makes_correct_number_of_queries_on_relation
    post = posts(:welcome)
    relation = Post.where(id: post.id)

    assert_queries(2) do
      preloader = ActiveRecord::Associations::Preloader.new(records: relation, associations: :comments)
      preloader.call
    end
  end

  def test_preload_for_hmt_with_conditions
    post = posts(:welcome)
    _normal_category = post.categories.create!(name: "Normal")
    special_category = post.special_categories.create!(name: "Special")

    preloader = ActiveRecord::Associations::Preloader.new(records: [post], associations: :hmt_special_categories)
    preloader.call

    assert_equal 1, post.hmt_special_categories.length
    assert_equal [special_category], post.hmt_special_categories
  end

  def test_preload_groups_queries_with_same_scope
    book = books(:awdr)
    post = posts(:welcome)

    assert_queries(1) do
      preloader = ActiveRecord::Associations::Preloader.new(records: [book, post], associations: :author)
      preloader.call
    end

    assert_no_queries do
      book.author
      post.author
    end
  end

  def test_preload_grouped_queries_with_already_loaded_records
    book = books(:awdr)
    post = posts(:welcome)
    book.author

    assert_no_queries do
      ActiveRecord::Associations::Preloader.new(records: [book, post], associations: :author).call
      book.author
      post.author
    end
  end

  def test_preload_grouped_queries_of_middle_records
    comments = [
      comments(:eager_sti_on_associations_s_comment1),
      comments(:eager_sti_on_associations_s_comment2),
    ]

    assert_queries(2) do
      ActiveRecord::Associations::Preloader.new(records: comments, associations: [:author, :ordinary_post]).call
    end
  end

  def test_preload_grouped_queries_of_through_records
    author = authors(:david)

    assert_queries(3) do
      ActiveRecord::Associations::Preloader.new(records: [author], associations: [:hello_post_comments, :comments]).call
    end
  end

  def test_preload_with_instance_dependent_scope
    david = authors(:david)
    david2 = Author.create!(name: "David")
    bob = authors(:bob)
    post = Post.create!(
      author: david,
      title: "test post",
      body: "this post is about David"
    )
    post2 = Post.create!(
      author: david,
      title: "test post 2",
      body: "this post is also about David"
    )

    assert_queries(2) do
      preloader = ActiveRecord::Associations::Preloader.new(records: [david, david2, bob], associations: :posts_mentioning_author)
      preloader.call
    end

    assert_predicate david.posts_mentioning_author, :loaded?
    assert_predicate david2.posts_mentioning_author, :loaded?
    assert_predicate bob.posts_mentioning_author, :loaded?

    assert_equal [post, post2].sort, david.posts_mentioning_author.sort
    assert_equal [], david2.posts_mentioning_author
    assert_equal [], bob.posts_mentioning_author
  end

  def test_preload_with_instance_dependent_through_scope
    david = authors(:david)
    david2 = Author.create!(name: "David")
    bob = authors(:bob)
    comment1 = david.posts.first.comments.create!(body: "Hi David!")
    comment2 = david.posts.first.comments.create!(body: "This comment mentions david")

    assert_queries(2) do
      preloader = ActiveRecord::Associations::Preloader.new(records: [david, david2, bob], associations: :comments_mentioning_author)
      preloader.call
    end

    assert_predicate david.comments_mentioning_author, :loaded?
    assert_predicate david2.comments_mentioning_author, :loaded?
    assert_predicate bob.comments_mentioning_author, :loaded?

    assert_equal [comment1, comment2].sort, david.comments_mentioning_author.sort
    assert_equal [], david2.comments_mentioning_author
    assert_equal [], bob.comments_mentioning_author
  end

  def test_preload_with_through_instance_dependent_scope
    david = authors(:david)
    david2 = Author.create!(name: "David")
    bob = authors(:bob)
    post = Post.create!(
      author: david,
      title: "test post",
      body: "this post is about David"
    )
    Post.create!(
      author: david,
      title: "test post 2",
      body: "this post is also about David"
    )
    post3 = Post.create!(
      author: bob,
      title: "test post 3",
      body: "this post is about Bob"
    )
    comment1 = post.comments.create!(body: "hi!")
    comment2 = post.comments.create!(body: "hello!")
    comment3 = post3.comments.create!(body: "HI BOB!")

    assert_queries(3) do
      preloader = ActiveRecord::Associations::Preloader.new(records: [david, david2, bob], associations: :comments_on_posts_mentioning_author)
      preloader.call
    end

    assert_predicate david.comments_on_posts_mentioning_author, :loaded?
    assert_predicate david2.comments_on_posts_mentioning_author, :loaded?
    assert_predicate bob.comments_on_posts_mentioning_author, :loaded?

    assert_equal [comment1, comment2].sort, david.comments_on_posts_mentioning_author.sort
    assert_equal [], david2.comments_on_posts_mentioning_author
    assert_equal [comment3], bob.comments_on_posts_mentioning_author
  end

  def test_some_already_loaded_associations
    item_discount = Discount.create(amount: 5)
    shipping_discount = Discount.create(amount: 20)

    invoice = Invoice.new
    line_item = LineItem.new(amount: 20)
    line_item.discount_applications << LineItemDiscountApplication.new(discount: item_discount)
    invoice.line_items << line_item

    shipping_line = ShippingLine.new(amount: 50)
    shipping_line.discount_applications << ShippingLineDiscountApplication.new(discount: shipping_discount)
    invoice.shipping_lines << shipping_line

    invoice.save!
    invoice.reload

    # SELECT "line_items".* FROM "line_items" WHERE "line_items"."invoice_id" = ?
    # SELECT "shipping_lines".* FROM shipping_lines WHERE "shipping_lines"."invoice_id" = ?
    # SELECT "line_item_discount_applications".* FROM "line_item_discount_applications" WHERE "line_item_discount_applications"."line_item_id" = ?
    # SELECT "shipping_line_discount_applications".* FROM "shipping_line_discount_applications" WHERE "shipping_line_discount_applications"."shipping_line_id" = ?
    # SELECT "discounts".* FROM "discounts" WHERE "discounts"."id" IN (?, ?).
    assert_queries(5) do
      preloader = ActiveRecord::Associations::Preloader.new(records: [invoice], associations: [
        line_items: { discount_applications: :discount },
        shipping_lines: { discount_applications: :discount },
      ])
      preloader.call
    end

    assert_no_queries do
      assert_not_nil invoice.line_items.first.discount_applications.first.discount
      assert_not_nil invoice.shipping_lines.first.discount_applications.first.discount
    end

    invoice.reload
    invoice.line_items.map { |i| i.discount_applications.to_a }
    # `line_items` and `line_item_discount_applications` are already preloaded, so we expect:
    # SELECT "shipping_lines".* FROM shipping_lines WHERE "shipping_lines"."invoice_id" = ?
    # SELECT "shipping_line_discount_applications".* FROM "shipping_line_discount_applications" WHERE "shipping_line_discount_applications"."shipping_line_id" = ?
    # SELECT "discounts".* FROM "discounts" WHERE "discounts"."id" = ?.
    assert_queries(3) do
      preloader = ActiveRecord::Associations::Preloader.new(records: [invoice], associations: [
        line_items: { discount_applications: :discount },
        shipping_lines: { discount_applications: :discount },
      ])
      preloader.call
    end

    assert_no_queries do
      assert_not_nil invoice.line_items.first.discount_applications.first.discount
      assert_not_nil invoice.shipping_lines.first.discount_applications.first.discount
    end
  end

  def test_preload_through
    comments = [
      comments(:eager_sti_on_associations_s_comment1),
      comments(:eager_sti_on_associations_s_comment2),
    ]

    assert_queries(2) do
      preloader = ActiveRecord::Associations::Preloader.new(records: comments, associations: [:author, :post])
      preloader.call
    end

    assert_no_queries do
      comments.each(&:author)
    end
  end

  def test_preload_groups_queries_with_same_scope_at_second_level
    author = nil

    # Expected
    #   SELECT FROM authors ...
    #   SELECT FROM posts ... (thinking)
    #   SELECT FROM posts ... (welcome)
    #   SELECT FROM comments ... (comments for both welcome and thinking)
    assert_queries(4) do
      author = Author
        .where(name: "David")
        .includes(thinking_posts: :comments, welcome_posts: :comments)
        .first
    end

    assert_no_queries do
      author.thinking_posts.map(&:comments)
      author.welcome_posts.map(&:comments)
    end
  end

  def test_preload_groups_queries_with_same_sql_at_second_level
    author = nil

    # Expected
    #   SELECT FROM authors ...
    #   SELECT FROM posts ... (thinking)
    #   SELECT FROM posts ... (welcome)
    #   SELECT FROM comments ... (comments for both welcome and thinking)
    assert_queries(4) do
      author = Author
        .where(name: "David")
        .includes(thinking_posts: :comments, welcome_posts: :comments_with_extending)
        .first
    end

    assert_no_queries do
      author.thinking_posts.map(&:comments)
      author.welcome_posts.map(&:comments_with_extending)
    end
  end

  def test_preload_with_grouping_sets_inverse_association
    mary = authors(:mary)
    bob = authors(:bob)

    AuthorFavorite.create!(author: mary, favorite_author: bob)
    favorites = AuthorFavorite.all.load

    assert_queries(1) do
      preloader = ActiveRecord::Associations::Preloader.new(records: favorites, associations: [:author, :favorite_author])
      preloader.call
    end

    assert_no_queries do
      favorites.first.author
      favorites.first.favorite_author
    end
  end

  def test_preload_can_group_separate_levels
    mary = authors(:mary)
    bob = authors(:bob)

    AuthorFavorite.create!(author: mary, favorite_author: bob)

    assert_queries(3) do
      preloader = ActiveRecord::Associations::Preloader.new(records: [mary], associations: [:posts, favorite_authors: :posts])
      preloader.call
    end

    assert_no_queries do
      mary.posts
      mary.favorite_authors.map(&:posts)
    end
  end

  def test_preload_can_group_multi_level_ping_pong_through
    mary = authors(:mary)
    bob = authors(:bob)

    AuthorFavorite.create!(author: mary, favorite_author: bob)

    associations = { similar_posts: :comments, favorite_authors: { similar_posts: :comments } }

    assert_queries(9) do
      preloader = ActiveRecord::Associations::Preloader.new(records: [mary], associations: associations)
      preloader.call
    end

    assert_no_queries do
      mary.similar_posts.map(&:comments).each(&:to_a)
      mary.favorite_authors.flat_map(&:similar_posts).map(&:comments).each(&:to_a)
    end

    # Preloading with automatic scope inversing reduces the number of queries
    tag_reflection = Tagging.reflect_on_association(:tag)
    taggings_reflection = Tag.reflect_on_association(:taggings)

    assert tag_reflection.scope
    assert_not taggings_reflection.scope

    with_automatic_scope_inversing(tag_reflection, taggings_reflection) do
      mary.reload

      assert_queries(8) do
        preloader = ActiveRecord::Associations::Preloader.new(records: [mary], associations: associations)
        preloader.call
      end
    end
  end

  def test_preload_does_not_group_same_class_different_scope
    post = posts(:welcome)
    postesque = Postesque.create(author: Author.last)
    postesque.reload

    # When the scopes differ in the generated SQL:
    # SELECT "authors".* FROM "authors" WHERE (name LIKE '%a%') AND "authors"."id" = ?
    # SELECT "authors".* FROM "authors" WHERE "authors"."id" = ?.
    assert_queries(2) do
      preloader = ActiveRecord::Associations::Preloader.new(records: [post, postesque], associations: :author_with_the_letter_a)
      preloader.call
    end

    assert_no_queries do
      post.author_with_the_letter_a
      postesque.author_with_the_letter_a
    end

    post.reload
    postesque.reload

    # When the generated SQL is identical, but one scope has preload values.
    assert_queries(3) do
      preloader = ActiveRecord::Associations::Preloader.new(records: [post, postesque], associations: :author_with_address)
      preloader.call
    end

    assert_no_queries do
      post.author_with_address
      postesque.author_with_address
    end
  end

  def test_preload_does_not_group_same_scope_different_key_name
    post = posts(:welcome)
    postesque = Postesque.create(author: Author.last)
    postesque.reload

    assert_queries(2) do
      preloader = ActiveRecord::Associations::Preloader.new(records: [post, postesque], associations: :author)
      preloader.call
    end

    assert_no_queries do
      post.author
      postesque.author
    end
  end

  def test_preload_with_available_records
    post = posts(:welcome)
    david = authors(:david)

    assert_no_queries do
      ActiveRecord::Associations::Preloader.new(records: [post], associations: :author, available_records: [[david]]).call

      assert_predicate post.association(:author), :loaded?
      assert_same david, post.author
    end
  end

  def test_preload_with_available_records_sti
    book = Book.create!
    essay_special = EssaySpecial.create!
    book.essay = essay_special
    book.save!
    book.reload

    assert_not_predicate book.association(:essay), :loaded?

    assert_no_queries do
      ActiveRecord::Associations::Preloader.new(records: [book], associations: :essay, available_records: [[essay_special]]).call
    end

    assert_predicate book.association(:essay), :loaded?
    assert_same essay_special, book.essay
  end

  def test_preload_with_only_some_records_available
    bob_post = posts(:misc_by_bob)
    mary_post = posts(:misc_by_mary)
    bob = authors(:bob)
    mary = authors(:mary)

    assert_queries(1) do
      ActiveRecord::Associations::Preloader.new(records: [bob_post, mary_post], associations: :author, available_records: [bob]).call
    end

    assert_no_queries do
      assert_same bob, bob_post.author
      assert_equal mary, mary_post.author
    end
  end

  def test_preload_with_some_records_already_loaded
    bob_post = posts(:misc_by_bob)
    mary_post = posts(:misc_by_mary)
    bob = bob_post.author
    mary = authors(:mary)

    assert bob_post.association(:author).loaded?
    assert_not mary_post.association(:author).loaded?

    assert_queries(1) do
      ActiveRecord::Associations::Preloader.new(records: [bob_post, mary_post], associations: :author).call
    end

    assert_no_queries do
      assert_same bob, bob_post.author
      assert_equal mary, mary_post.author
    end
  end

  def test_preload_with_available_records_with_through_association
    author = authors(:david)
    categories = Category.all.to_a

    assert_queries(1) do
      # One query to get the middle records (i.e. essays)
      ActiveRecord::Associations::Preloader.new(records: [author], associations: :essay_category, available_records: categories).call
    end

    assert_predicate author.association(:essay_category), :loaded?
    assert categories.map(&:object_id).include?(author.essay_category.object_id)
  end

  def test_preload_with_only_some_records_available_with_through_associations
    mary = authors(:mary)
    mary_essay = essays(:mary_stay_home)
    mary_category = categories(:technology)
    mary_essay.update!(category: mary_category)

    dave = authors(:david)
    dave_category = categories(:general)

    assert_queries(2) do
      ActiveRecord::Associations::Preloader.new(records: [mary, dave], associations: :essay_category, available_records: [mary_category]).call
    end

    assert_no_queries do
      assert_same mary_category, mary.essay_category
      assert_equal dave_category, dave.essay_category
    end
  end

  def test_preload_with_available_records_with_multiple_classes
    essay = essays(:david_modest_proposal)
    general = categories(:general)
    david = authors(:david)

    assert_no_queries do
      ActiveRecord::Associations::Preloader.new(records: [essay], associations: [:category, :author], available_records: [general, david]).call

      assert_predicate essay.association(:category), :loaded?
      assert_predicate essay.association(:author), :loaded?
      assert_same general, essay.category
      assert_same david, essay.author
    end
  end

  def test_preload_with_available_records_queries_when_scoped
    post = posts(:welcome)
    david = authors(:david)

    assert_queries(1) do
      ActiveRecord::Associations::Preloader.new(records: [post], associations: :author, scope: Author.where(name: "David"), available_records: [david]).call
    end

    assert_predicate post.association(:author), :loaded?
    assert_not_equal david.object_id, post.author.object_id
  end

  def test_preload_with_available_records_queries_when_collection
    post = posts(:welcome)
    comments = Comment.all.to_a

    assert_queries(1) do
      ActiveRecord::Associations::Preloader.new(records: [post], associations: :comments, available_records: comments).call
    end

    assert_predicate post.association(:comments), :loaded?
    assert_empty post.comments.map(&:object_id) & comments.map(&:object_id)
  end

  def test_preload_with_available_records_queries_when_incomplete
    post = posts(:welcome)
    bob = authors(:bob)
    david = authors(:david)

    assert_queries(1) do
      ActiveRecord::Associations::Preloader.new(records: [post], associations: :author, available_records: [bob]).call
    end

    assert_no_queries do
      assert_predicate post.association(:author), :loaded?
      assert_equal david, post.author
    end
  end

  def test_preload_with_unpersisted_records_no_ops
    author = Author.new
    new_post_with_author = Post.new(author: author)
    new_post_without_author = Post.new
    posts = [new_post_with_author, new_post_without_author]

    assert_no_queries do
      ActiveRecord::Associations::Preloader.new(records: posts, associations: :author).call

      assert_same author, new_post_with_author.author
      assert_nil new_post_without_author.author
    end
  end

  def test_preload_wont_set_the_wrong_target
    post = posts(:welcome)
    post.update!(author_id: 54321)
    some_other_record = categories(:general)
    some_other_record.update!(id: 54321)

    assert_raises do
      some_other_record.association(:author)
    end

    assert_nothing_raised do
      ActiveRecord::Associations::Preloader.new(records: [post], associations: :author, available_records: [[some_other_record]]).call
      assert post.association(:author).loaded?
      assert_not_equal some_other_record, post.author
    end
  end
end

class GeneratedMethodsTest < ActiveRecord::TestCase
  fixtures :developers, :computers, :posts, :comments

  def test_association_methods_override_attribute_methods_of_same_name
    assert_equal(developers(:david), computers(:workstation).developer)
    # this next line will fail if the attribute methods module is generated lazily
    # after the association methods module is generated
    assert_equal(developers(:david), computers(:workstation).developer)
    assert_equal(developers(:david).id, computers(:workstation)[:developer])
  end

  def test_model_method_overrides_association_method
    assert_equal(comments(:greetings).body, posts(:welcome).first_comment)
  end

  module MyModule
    def comments; :none end
  end

  class MyArticle < ActiveRecord::Base
    self.table_name = "articles"
    include MyModule
    has_many :comments, inverse_of: false
  end

  def test_included_module_overwrites_association_methods
    assert_equal :none, MyArticle.new.comments
  end
end

class WithAnnotationsTest < ActiveRecord::TestCase
  fixtures :pirates, :parrots

  def test_belongs_to_with_annotation_includes_a_query_comment
    pirate = SpacePirate.where.not(parrot_id: nil).first
    assert pirate, "should have a Pirate record"

    log = capture_sql do
      pirate.parrot
    end
    assert_not_predicate log, :empty?
    assert_predicate log.select { |query| query.match?(%r{/\*}) }, :empty?

    assert_sql(%r{/\* that tells jokes \*/}) do
      pirate.parrot_with_annotation
    end
  end

  def test_has_and_belongs_to_many_with_annotation_includes_a_query_comment
    pirate = SpacePirate.first
    assert pirate, "should have a Pirate record"

    log = capture_sql do
      pirate.parrots.first
    end
    assert_not_predicate log, :empty?
    assert_predicate log.select { |query| query.match?(%r{/\*}) }, :empty?

    assert_sql(%r{/\* that are very colorful \*/}) do
      pirate.parrots_with_annotation.first
    end
  end

  def test_has_one_with_annotation_includes_a_query_comment
    pirate = SpacePirate.first
    assert pirate, "should have a Pirate record"

    log = capture_sql do
      pirate.ship
    end
    assert_not_predicate log, :empty?
    assert_predicate log.select { |query| query.match?(%r{/\*}) }, :empty?

    assert_sql(%r{/\* that is a rocket \*/}) do
      pirate.ship_with_annotation
    end
  end

  def test_has_many_with_annotation_includes_a_query_comment
    pirate = SpacePirate.first
    assert pirate, "should have a Pirate record"

    log = capture_sql do
      pirate.birds.first
    end
    assert_not_predicate log, :empty?
    assert_predicate log.select { |query| query.match?(%r{/\*}) }, :empty?

    assert_sql(%r{/\* that are also parrots \*/}) do
      pirate.birds_with_annotation.first
    end
  end

  def test_has_many_through_with_annotation_includes_a_query_comment
    pirate = SpacePirate.first
    assert pirate, "should have a Pirate record"

    log = capture_sql do
      pirate.treasure_estimates.first
    end
    assert_not_predicate log, :empty?
    assert_predicate log.select { |query| query.match?(%r{/\*}) }, :empty?

    assert_sql(%r{/\* yarrr \*/}) do
      pirate.treasure_estimates_with_annotation.first
    end
  end

  def test_has_many_through_with_annotation_includes_a_query_comment_when_eager_loading
    pirate = SpacePirate.first
    assert pirate, "should have a Pirate record"

    log = capture_sql do
      pirate.treasure_estimates.first
    end
    assert_not_predicate log, :empty?
    assert_predicate log.select { |query| query.match?(%r{/\*}) }, :empty?

    assert_sql(%r{/\* yarrr \*/}) do
      SpacePirate.includes(:treasure_estimates_with_annotation, :treasures).first
    end
  end
end