path: root/activerecord/test/cases/relations_test.rb

require "cases/helper"
require "models/tag"
require "models/tagging"
require "models/post"
require "models/topic"
require "models/comment"
require "models/author"
require "models/entrant"
require "models/developer"
require "models/computer"
require "models/reply"
require "models/company"
require "models/bird"
require "models/car"
require "models/engine"
require "models/tyre"
require "models/minivan"
require "models/aircraft"
require "models/possession"
require "models/reader"
require "models/categorization"
require "models/edge"

class RelationTest < ActiveRecord::TestCase
  fixtures :authors, :topics, :entrants, :developers, :companies, :developers_projects, :accounts, :categories, :categorizations, :posts, :comments,
    :tags, :taggings, :cars, :minivans

  class TopicWithCallbacks < ActiveRecord::Base
    self.table_name = :topics
    before_update { |topic| topic.author_name = "David" if topic.author_name.blank? }
  end

  def test_do_not_double_quote_string_id
    van = Minivan.last
    assert van
    assert_equal van.id, Minivan.where(minivan_id: van).to_a.first.minivan_id
  end

  def test_do_not_double_quote_string_id_with_array
    van = Minivan.last
    assert van
    assert_equal van, Minivan.where(minivan_id: [van]).to_a.first
  end

  def test_two_scopes_with_includes_should_not_drop_any_include
    # heat habtm cache
    car = Car.incl_engines.incl_tyres.first
    car.tyres.length
    car.engines.length

    car = Car.incl_engines.incl_tyres.first
    assert_no_queries { car.tyres.length }
    assert_no_queries { car.engines.length }
  end

  def test_dynamic_finder
    x = Post.where("author_id = ?", 1)
    assert x.klass.respond_to?(:find_by_id), "@klass should handle dynamic finders"
  end

  def test_multivalue_where
    posts = Post.where("author_id = ? AND id = ?", 1, 1)
    assert_equal 1, posts.to_a.size
  end

  def test_scoped
    topics = Topic.all
    assert_kind_of ActiveRecord::Relation, topics
    assert_equal 5, topics.size
  end

  def test_to_json
    assert_nothing_raised  { Bird.all.to_json }
    assert_nothing_raised  { Bird.all.to_a.to_json }
  end

  def test_to_yaml
    assert_nothing_raised  { Bird.all.to_yaml }
    assert_nothing_raised  { Bird.all.to_a.to_yaml }
  end

  def test_to_xml
    assert_nothing_raised  { Bird.all.to_xml }
    assert_nothing_raised  { Bird.all.to_a.to_xml }
  end

  def test_scoped_all
    topics = Topic.all.to_a
    assert_kind_of Array, topics
    assert_no_queries { assert_equal 5, topics.size }
  end

  def test_loaded_all
    topics = Topic.all

    assert_queries(1) do
      2.times { assert_equal 5, topics.to_a.size }
    end

    assert topics.loaded?
  end

  def test_scoped_first
    topics = Topic.all.order("id ASC")

    assert_queries(1) do
      2.times { assert_equal "The First Topic", topics.first.title }
    end

    assert ! topics.loaded?
  end

  def test_loaded_first
    topics = Topic.all.order("id ASC")
    topics.to_a # force load

    assert_no_queries do
      assert_equal "The First Topic", topics.first.title
    end

    assert topics.loaded?
  end

  def test_loaded_first_with_limit
    topics = Topic.all.order("id ASC")
    topics.to_a # force load

    assert_no_queries do
      assert_equal ["The First Topic",
                    "The Second Topic of the day"], topics.first(2).map(&:title)
    end

    assert topics.loaded?
  end

  def test_first_get_more_than_available
    topics = Topic.all.order("id ASC")
    unloaded_first = topics.first(10)
    topics.to_a # force load

    assert_no_queries do
      loaded_first = topics.first(10)
      assert_equal unloaded_first, loaded_first
    end
  end

  def test_reload
    topics = Topic.all

    assert_queries(1) do
      2.times { topics.to_a }
    end

    assert topics.loaded?

    original_size = topics.to_a.size
    Topic.create! title: "fake"

    assert_queries(1) { topics.reload }
    assert_equal original_size + 1, topics.size
    assert topics.loaded?
  end

  def test_finding_with_subquery
    relation = Topic.where(approved: true)
    assert_equal relation.to_a, Topic.select("*").from(relation).to_a
    assert_equal relation.to_a, Topic.select("subquery.*").from(relation).to_a
    assert_equal relation.to_a, Topic.select("a.*").from(relation, :a).to_a
  end

  def test_finding_with_subquery_with_binds
    relation = Post.first.comments
    assert_equal relation.to_a, Comment.select("*").from(relation).to_a
    assert_equal relation.to_a, Comment.select("subquery.*").from(relation).to_a
    assert_equal relation.to_a, Comment.select("a.*").from(relation, :a).to_a
  end

  def test_finding_with_subquery_without_select_does_not_change_the_select
    relation = Topic.where(approved: true)
    assert_raises(ActiveRecord::StatementInvalid) do
      Topic.from(relation).to_a
    end
  end

  def test_select_with_subquery_in_from_does_not_use_original_table_name
    relation = Comment.group(:type).select("COUNT(post_id) AS post_count, type")
    subquery = Comment.from(relation).select("type","post_count")
    assert_equal(relation.map(&:post_count).sort,subquery.map(&:post_count).sort)
  end

  def test_group_with_subquery_in_from_does_not_use_original_table_name
    relation = Comment.group(:type).select("COUNT(post_id) AS post_count,type")
    subquery = Comment.from(relation).group("type").average("post_count")
    assert_equal(relation.map(&:post_count).sort,subquery.values.sort)
  end

  def test_finding_with_conditions
    assert_equal ["David"], Author.where(name: "David").map(&:name)
    assert_equal ["Mary"],  Author.where(["name = ?", "Mary"]).map(&:name)
    assert_equal ["Mary"],  Author.where("name = ?", "Mary").map(&:name)
  end

  def test_finding_with_order
    topics = Topic.order("id")
    assert_equal 5, topics.to_a.size
    assert_equal topics(:first).title, topics.first.title
  end

  def test_finding_with_arel_order
    topics = Topic.order(Topic.arel_table[:id].asc)
    assert_equal 5, topics.to_a.size
    assert_equal topics(:first).title, topics.first.title
  end

  def test_finding_with_assoc_order
    topics = Topic.order(id: :desc)
    assert_equal 5, topics.to_a.size
    assert_equal topics(:fifth).title, topics.first.title
  end

  def test_finding_with_reverted_assoc_order
    topics = Topic.order(id: :asc).reverse_order
    assert_equal 5, topics.to_a.size
    assert_equal topics(:fifth).title, topics.first.title
  end

  def test_reverse_order_with_function
    topics = Topic.order("length(title)").reverse_order
    assert_equal topics(:second).title, topics.first.title
  end

  def test_reverse_order_with_function_other_predicates
    topics = Topic.order("author_name, length(title), id").reverse_order
    assert_equal topics(:second).title, topics.first.title
    topics = Topic.order("length(author_name), id, length(title)").reverse_order
    assert_equal topics(:fifth).title, topics.first.title
  end

  def test_reverse_order_with_multiargument_function
    assert_raises(ActiveRecord::IrreversibleOrderError) do
      Topic.order("concat(author_name, title)").reverse_order
    end
    assert_raises(ActiveRecord::IrreversibleOrderError) do
      Topic.order("concat(lower(author_name), title)").reverse_order
    end
    assert_raises(ActiveRecord::IrreversibleOrderError) do
      Topic.order("concat(author_name, lower(title))").reverse_order
    end
    assert_raises(ActiveRecord::IrreversibleOrderError) do
      Topic.order("concat(lower(author_name), title, length(title)").reverse_order
    end
  end

  def test_reverse_order_with_nulls_first_or_last
    assert_raises(ActiveRecord::IrreversibleOrderError) do
      Topic.order("title NULLS FIRST").reverse_order
    end
    assert_raises(ActiveRecord::IrreversibleOrderError) do
      Topic.order("title nulls last").reverse_order
    end
  end

  def test_default_reverse_order_on_table_without_primary_key
    assert_raises(ActiveRecord::IrreversibleOrderError) do
      Edge.all.reverse_order
    end
  end

  def test_order_with_hash_and_symbol_generates_the_same_sql
    assert_equal Topic.order(:id).to_sql, Topic.order(id: :asc).to_sql
  end

  def test_finding_with_desc_order_with_string
    topics = Topic.order(id: "desc")
    assert_equal 5, topics.to_a.size
    assert_equal [topics(:fifth), topics(:fourth), topics(:third), topics(:second), topics(:first)], topics.to_a
  end

  def test_finding_with_asc_order_with_string
    topics = Topic.order(id: "asc")
    assert_equal 5, topics.to_a.size
    assert_equal [topics(:first), topics(:second), topics(:third), topics(:fourth), topics(:fifth)], topics.to_a
  end

  def test_support_upper_and_lower_case_directions
    assert_includes Topic.order(id: "ASC").to_sql, "ASC"
    assert_includes Topic.order(id: "asc").to_sql, "ASC"
    assert_includes Topic.order(id: :ASC).to_sql, "ASC"
    assert_includes Topic.order(id: :asc).to_sql, "ASC"

    assert_includes Topic.order(id: "DESC").to_sql, "DESC"
    assert_includes Topic.order(id: "desc").to_sql, "DESC"
    assert_includes Topic.order(id: :DESC).to_sql, "DESC"
    assert_includes Topic.order(id: :desc).to_sql,"DESC"
  end

  def test_raising_exception_on_invalid_hash_params
    e = assert_raise(ArgumentError) { Topic.order(:name, "id DESC", id: :asfsdf) }
    assert_equal 'Direction "asfsdf" is invalid. Valid directions are: [:asc, :desc, :ASC, :DESC, "asc", "desc", "ASC", "DESC"]', e.message
  end

  def test_finding_last_with_arel_order
    topics = Topic.order(Topic.arel_table[:id].asc)
    assert_equal topics(:fifth).title, topics.last.title
  end

  def test_finding_with_order_concatenated
    topics = Topic.order("author_name").order("title")
    assert_equal 5, topics.to_a.size
    assert_equal topics(:fourth).title, topics.first.title
  end

  def test_finding_with_order_by_aliased_attributes
    topics = Topic.order(:heading)
    assert_equal 5, topics.to_a.size
    assert_equal topics(:fifth).title, topics.first.title
  end

  def test_finding_with_assoc_order_by_aliased_attributes
    topics = Topic.order(heading: :desc)
    assert_equal 5, topics.to_a.size
    assert_equal topics(:third).title, topics.first.title
  end

  def test_finding_with_reorder
    topics = Topic.order("author_name").order("title").reorder("id").to_a
    topics_titles = topics.map(&:title)
    assert_equal ["The First Topic", "The Second Topic of the day", "The Third Topic of the day", "The Fourth Topic of the day", "The Fifth Topic of the day"], topics_titles
  end

  def test_finding_with_reorder_by_aliased_attributes
    topics = Topic.order("author_name").reorder(:heading)
    assert_equal 5, topics.to_a.size
    assert_equal topics(:fifth).title, topics.first.title
  end

  def test_finding_with_assoc_reorder_by_aliased_attributes
    topics = Topic.order("author_name").reorder(heading: :desc)
    assert_equal 5, topics.to_a.size
    assert_equal topics(:third).title, topics.first.title
  end

  def test_finding_with_order_and_take
    entrants = Entrant.order("id ASC").limit(2).to_a

    assert_equal 2, entrants.size
    assert_equal entrants(:first).name, entrants.first.name
  end

  def test_finding_with_cross_table_order_and_limit
    tags = Tag.includes(:taggings).
              order("tags.name asc", "taggings.taggable_id asc", "REPLACE('abc', taggings.taggable_type, taggings.taggable_type)").
              limit(1).to_a
    assert_equal 1, tags.length
  end

  def test_finding_with_complex_order_and_limit
    tags = Tag.includes(:taggings).references(:taggings).order("REPLACE('abc', taggings.taggable_type, taggings.taggable_type)").limit(1).to_a
    assert_equal 1, tags.length
  end

  def test_finding_with_complex_order
    tags = Tag.includes(:taggings).references(:taggings).order("REPLACE('abc', taggings.taggable_type, taggings.taggable_type)").to_a
    assert_equal 3, tags.length
  end

  def test_finding_with_sanitized_order
    query = Tag.order(["field(id, ?)", [1,3,2]]).to_sql
    assert_match(/field\(id, 1,3,2\)/, query)

    query = Tag.order(["field(id, ?)", []]).to_sql
    assert_match(/field\(id, NULL\)/, query)

    query = Tag.order(["field(id, ?)", nil]).to_sql
    assert_match(/field\(id, NULL\)/, query)
  end

  def test_finding_with_order_limit_and_offset
    entrants = Entrant.order("id ASC").limit(2).offset(1)

    assert_equal 2, entrants.to_a.size
    assert_equal entrants(:second).name, entrants.first.name

    entrants = Entrant.order("id ASC").limit(2).offset(2)
    assert_equal 1, entrants.to_a.size
    assert_equal entrants(:third).name, entrants.first.name
  end

  def test_finding_with_group
    developers = Developer.group("salary").select("salary").to_a
    assert_equal 4, developers.size
    assert_equal 4, developers.map(&:salary).uniq.size
  end

  def test_select_with_block
    even_ids = Developer.all.select { |d| d.id % 2 == 0 }.map(&:id)
    assert_equal [2, 4, 6, 8, 10], even_ids.sort
  end

  def test_none
    assert_no_queries(ignore_none: false) do
      assert_equal [], Developer.none
      assert_equal [], Developer.all.none
    end
  end

  def test_none_chainable
    assert_no_queries(ignore_none: false) do
      assert_equal [], Developer.none.where(name: "David")
    end
  end

  def test_none_chainable_to_existing_scope_extension_method
    assert_no_queries(ignore_none: false) do
      assert_equal 1, Topic.anonymous_extension.none.one
    end
  end

  def test_none_chained_to_methods_firing_queries_straight_to_db
    assert_no_queries(ignore_none: false) do
      assert_equal [],    Developer.none.pluck(:id, :name)
      assert_equal 0,     Developer.none.delete_all
      assert_equal 0,     Developer.none.update_all(name: "David")
      assert_equal 0,     Developer.none.delete(1)
      assert_equal false, Developer.none.exists?(1)
    end
  end

  def test_null_relation_content_size_methods
    assert_no_queries(ignore_none: false) do
      assert_equal 0,     Developer.none.size
      assert_equal 0,     Developer.none.count
      assert_equal true,  Developer.none.empty?
      assert_equal true, Developer.none.none?
      assert_equal false, Developer.none.any?
      assert_equal false, Developer.none.one?
      assert_equal false, Developer.none.many?
    end
  end

  def test_null_relation_calculations_methods
    assert_no_queries(ignore_none: false) do
      assert_equal 0, Developer.none.count
      assert_equal 0, Developer.none.calculate(:count, nil)
      assert_equal nil, Developer.none.calculate(:average, "salary")
    end
  end

  def test_null_relation_metadata_methods
    assert_equal "", Developer.none.to_sql
    assert_equal({}, Developer.none.where_values_hash)
  end

  def test_null_relation_where_values_hash
    assert_equal({ "salary" => 100_000 }, Developer.none.where(salary: 100_000).where_values_hash)
  end

  def test_null_relation_sum
    ac = Aircraft.new
    assert_equal Hash.new, ac.engines.group(:id).sum(:id)
    assert_equal        0, ac.engines.count
    ac.save
    assert_equal Hash.new, ac.engines.group(:id).sum(:id)
    assert_equal        0, ac.engines.count
  end

  def test_null_relation_count
    ac = Aircraft.new
    assert_equal Hash.new, ac.engines.group(:id).count
    assert_equal        0, ac.engines.count
    ac.save
    assert_equal Hash.new, ac.engines.group(:id).count
    assert_equal        0, ac.engines.count
  end

  def test_null_relation_size
    ac = Aircraft.new
    assert_equal Hash.new, ac.engines.group(:id).size
    assert_equal        0, ac.engines.size
    ac.save
    assert_equal Hash.new, ac.engines.group(:id).size
    assert_equal        0, ac.engines.size
  end

  def test_null_relation_average
    ac = Aircraft.new
    assert_equal Hash.new, ac.engines.group(:car_id).average(:id)
    assert_equal        nil, ac.engines.average(:id)
    ac.save
    assert_equal Hash.new, ac.engines.group(:car_id).average(:id)
    assert_equal        nil, ac.engines.average(:id)
  end

  def test_null_relation_minimum
    ac = Aircraft.new
    assert_equal Hash.new, ac.engines.group(:car_id).minimum(:id)
    assert_equal        nil, ac.engines.minimum(:id)
    ac.save
    assert_equal Hash.new, ac.engines.group(:car_id).minimum(:id)
    assert_equal        nil, ac.engines.minimum(:id)
  end

  def test_null_relation_maximum
    ac = Aircraft.new
    assert_equal Hash.new, ac.engines.group(:car_id).maximum(:id)
    assert_equal        nil, ac.engines.maximum(:id)
    ac.save
    assert_equal Hash.new, ac.engines.group(:car_id).maximum(:id)
    assert_equal        nil, ac.engines.maximum(:id)
  end

  def test_null_relation_in_where_condition
    assert_operator Comment.count, :>, 0 # precondition, make sure there are comments.
    assert_equal 0, Comment.where(post_id: Post.none).to_a.size
  end

  def test_joins_with_nil_argument
    assert_nothing_raised { DependentFirm.joins(nil).first }
  end

  def test_finding_with_hash_conditions_on_joined_table
    firms = DependentFirm.joins(:account).where(name: "RailsCore", accounts: { credit_limit: 55..60 }).to_a
    assert_equal 1, firms.size
    assert_equal companies(:rails_core), firms.first
  end

  def test_find_all_with_join
    developers_on_project_one = Developer.joins("LEFT JOIN developers_projects ON developers.id = developers_projects.developer_id").
      where("project_id=1").to_a

    assert_equal 3, developers_on_project_one.length
    developer_names = developers_on_project_one.map(&:name)
    assert_includes developer_names, "David"
    assert_includes developer_names, "Jamis"
  end

  def test_find_on_hash_conditions
    assert_equal Topic.all.merge!(where: { approved: false }).to_a, Topic.where(approved: false).to_a
  end

  def test_joins_with_string_array
    person_with_reader_and_post = Post.joins([
        "INNER JOIN categorizations ON categorizations.post_id = posts.id",
        "INNER JOIN categories ON categories.id = categorizations.category_id AND categories.type = 'SpecialCategory'"
      ]
    ).to_a
    assert_equal 1, person_with_reader_and_post.size
  end

  def test_no_arguments_to_query_methods_raise_errors
    assert_raises(ArgumentError) { Topic.references() }
    assert_raises(ArgumentError) { Topic.includes() }
    assert_raises(ArgumentError) { Topic.preload() }
    assert_raises(ArgumentError) { Topic.group() }
    assert_raises(ArgumentError) { Topic.reorder() }
  end

  def test_blank_like_arguments_to_query_methods_dont_raise_errors
    assert_nothing_raised { Topic.references([]) }
    assert_nothing_raised { Topic.includes([]) }
    assert_nothing_raised { Topic.preload([]) }
    assert_nothing_raised { Topic.group([]) }
    assert_nothing_raised { Topic.reorder([]) }
  end

  def test_scoped_responds_to_delegated_methods
    relation = Topic.all

    ["map", "uniq", "sort", "insert", "delete", "update"].each do |method|
      assert_respond_to relation, method, "Topic.all should respond to #{method.inspect}"
    end
  end

  def test_respond_to_delegates_to_relation
    relation = Topic.all
    fake_arel = Struct.new(:responds) {
      def respond_to?(method, access = false)
        responds << [method, access]
      end
    }.new []

    relation.extend(Module.new { attr_accessor :arel })
    relation.arel = fake_arel

    relation.respond_to?(:matching_attributes)
    assert_equal [:matching_attributes, false], fake_arel.responds.first

    fake_arel.responds = []
    relation.respond_to?(:matching_attributes, true)
    assert_equal [:matching_attributes, true], fake_arel.responds.first
  end

  def test_respond_to_dynamic_finders
    relation = Topic.all

    ["find_by_title", "find_by_title_and_author_name"].each do |method|
      assert_respond_to relation, method, "Topic.all should respond to #{method.inspect}"
    end
  end

  def test_respond_to_class_methods_and_scopes
    assert Topic.all.respond_to?(:by_lifo)
  end

  def test_find_with_readonly_option
    Developer.all.each { |d| assert !d.readonly? }
    Developer.all.readonly.each { |d| assert d.readonly? }
  end

  def test_eager_association_loading_of_stis_with_multiple_references
    authors = Author.eager_load(posts: { special_comments: { post: [ :special_comments, :very_special_comment ] } }).
      order("comments.body, very_special_comments_posts.body").where("posts.id = 4").to_a

    assert_equal [authors(:david)], authors
    assert_no_queries do
      authors.first.posts.first.special_comments.first.post.special_comments
      authors.first.posts.first.special_comments.first.post.very_special_comment
    end
  end

  def test_find_with_preloaded_associations
    assert_queries(2) do
      posts = Post.preload(:comments).order("posts.id")
      assert posts.first.comments.first
    end

    assert_queries(2) do
      posts = Post.preload(:comments).order("posts.id")
      assert posts.first.comments.first
    end

    assert_queries(2) do
      posts = Post.preload(:author).order("posts.id")
      assert posts.first.author
    end

    assert_queries(2) do
      posts = Post.preload(:author).order("posts.id")
      assert posts.first.author
    end

    assert_queries(3) do
      posts = Post.preload(:author, :comments).order("posts.id")
      assert posts.first.author
      assert posts.first.comments.first
    end
  end

  def test_preload_applies_to_all_chained_preloaded_scopes
    assert_queries(3) do
      post = Post.with_comments.with_tags.first
      assert post
    end
  end

  def test_find_with_included_associations
    assert_queries(2) do
      posts = Post.includes(:comments).order("posts.id")
      assert posts.first.comments.first
    end

    assert_queries(2) do
      posts = Post.all.includes(:comments).order("posts.id")
      assert posts.first.comments.first
    end

    assert_queries(2) do
      posts = Post.includes(:author).order("posts.id")
      assert posts.first.author
    end

    assert_queries(3) do
      posts = Post.includes(:author, :comments).order("posts.id")
      assert posts.first.author
      assert posts.first.comments.first
    end
  end

  def test_default_scope_with_conditions_string
    assert_equal Developer.where(name: "David").map(&:id).sort, DeveloperCalledDavid.all.map(&:id).sort
    assert_nil DeveloperCalledDavid.create!.name
  end

  def test_default_scope_with_conditions_hash
    assert_equal Developer.where(name: "Jamis").map(&:id).sort, DeveloperCalledJamis.all.map(&:id).sort
    assert_equal "Jamis", DeveloperCalledJamis.create!.name
  end

  def test_default_scoping_finder_methods
    developers = DeveloperCalledDavid.order("id").map(&:id).sort
    assert_equal Developer.where(name: "David").map(&:id).sort, developers
  end

  def test_includes_with_select
    query = Post.select("comments_count AS ranking").order("ranking").includes(:comments)
      .where(comments: { id: 1 })

    assert_equal ["comments_count AS ranking"], query.select_values
    assert_equal 1, query.to_a.size
  end

  def test_preloading_with_associations_and_merges
    post = Post.create! title: "Uhuu", body: "body"
    reader = Reader.create! post_id: post.id, person_id: 1
    comment = Comment.create! post_id: post.id, body: "body"

    assert !comment.respond_to?(:readers)

    post_rel = Post.preload(:readers).joins(:readers).where(title: "Uhuu")
    result_comment = Comment.joins(:post).merge(post_rel).to_a.first
    assert_equal comment, result_comment

    assert_no_queries do
      assert_equal post, result_comment.post
      assert_equal [reader], result_comment.post.readers.to_a
    end

    post_rel = Post.includes(:readers).where(title: "Uhuu")
    result_comment = Comment.joins(:post).merge(post_rel).first
    assert_equal comment, result_comment

    assert_no_queries do
      assert_equal post, result_comment.post
      assert_equal [reader], result_comment.post.readers.to_a
    end
  end

  def test_preloading_with_associations_default_scopes_and_merges
    post = Post.create! title: "Uhuu", body: "body"
    reader = Reader.create! post_id: post.id, person_id: 1

    post_rel = PostWithPreloadDefaultScope.preload(:readers).joins(:readers).where(title: "Uhuu")
    result_post = PostWithPreloadDefaultScope.all.merge(post_rel).to_a.first

    assert_no_queries do
      assert_equal [reader], result_post.readers.to_a
    end

    post_rel = PostWithIncludesDefaultScope.includes(:readers).where(title: "Uhuu")
    result_post = PostWithIncludesDefaultScope.all.merge(post_rel).to_a.first

    assert_no_queries do
      assert_equal [reader], result_post.readers.to_a
    end
  end

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

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

    posts = Post.preload(:last_comment)
    post = posts.find { |p| p.id == 1 }
    assert_equal Post.find(1).last_comment, post.last_comment
  end

  def test_to_sql_on_eager_join
    expected = assert_sql {
      Post.eager_load(:last_comment).order("comments.id DESC").to_a
    }.first
    actual = Post.eager_load(:last_comment).order("comments.id DESC").to_sql
    assert_equal expected, actual
  end

  def test_to_sql_on_scoped_proxy
    auth = Author.first
    Post.where("1=1").written_by(auth)
    assert_not auth.posts.to_sql.include?("1=1")
  end

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

  def test_dynamic_find_by_attributes
    david = authors(:david)
    author = Author.preload(:taggings).find_by_id(david.id)
    expected_taggings = taggings(:welcome_general, :thinking_general)

    assert_no_queries do
      assert_equal expected_taggings, author.taggings.distinct.sort_by(&:id)
      assert_equal expected_taggings, author.taggings.uniq.sort_by(&:id)
    end

    authors = Author.all
    assert_equal david, authors.find_by_id_and_name(david.id, david.name)
    assert_equal david, authors.find_by_id_and_name!(david.id, david.name)
  end

  def test_dynamic_find_by_attributes_bang
    author = Author.all.find_by_id!(authors(:david).id)
    assert_equal "David", author.name

    assert_raises(ActiveRecord::RecordNotFound) { Author.all.find_by_id_and_name!(20, "invalid") }
  end

  def test_find_id
    authors = Author.all

    david = authors.find(authors(:david).id)
    assert_equal "David", david.name

    assert_raises(ActiveRecord::RecordNotFound) { authors.where(name: "lifo").find("42") }
  end

  def test_find_ids
    authors = Author.order("id ASC")

    results = authors.find(authors(:david).id, authors(:mary).id)
    assert_kind_of Array, results
    assert_equal 2, results.size
    assert_equal "David", results[0].name
    assert_equal "Mary", results[1].name
    assert_equal results, authors.find([authors(:david).id, authors(:mary).id])

    assert_raises(ActiveRecord::RecordNotFound) { authors.where(name: "lifo").find(authors(:david).id, "42") }
    assert_raises(ActiveRecord::RecordNotFound) { authors.find(["42", 43]) }
  end

  def test_find_in_empty_array
    authors = Author.all.where(id: [])
    assert authors.to_a.blank?
  end

  def test_where_with_ar_object
    author = Author.first
    authors = Author.all.where(id: author)
    assert_equal 1, authors.to_a.length
  end

  def test_find_with_list_of_ar
    author = Author.first
    authors = Author.find([author.id])
    assert_equal author, authors.first
  end

  class Mary < Author; end

  def test_find_by_classname
    Author.create!(name: Mary.name)
    assert_deprecated do
      assert_equal 1, Author.where(name: Mary).size
    end
  end

  def test_find_by_id_with_list_of_ar
    author = Author.first
    authors = Author.find_by_id([author])
    assert_equal author, authors
  end

  def test_find_all_using_where_twice_should_or_the_relation
    david = authors(:david)
    relation = Author.unscoped
    relation = relation.where(name: david.name)
    relation = relation.where(name: "Santiago")
    relation = relation.where(id: david.id)
    assert_equal [], relation.to_a
  end

  def test_multi_where_ands_queries
    relation = Author.unscoped
    david = authors(:david)
    sql = relation.where(name: david.name).where(name: "Santiago").to_sql
    assert_match("AND", sql)
  end

  def test_find_all_with_multiple_should_use_and
    david = authors(:david)
    relation = [
      { name: david.name },
      { name: "Santiago" },
      { name: "tenderlove" },
    ].inject(Author.unscoped) do |memo, param|
      memo.where(param)
    end
    assert_equal [], relation.to_a
  end

  def test_typecasting_where_with_array
    ids = Author.pluck(:id)
    slugs = ids.map { |id| "#{id}-as-a-slug" }

    assert_equal Author.all.to_a, Author.where(id: slugs).to_a
  end

  def test_find_all_using_where_with_relation
    david = authors(:david)
    # switching the lines below would succeed in current rails
    # assert_queries(2) {
    assert_queries(1) {
      relation = Author.where(id: Author.where(id: david.id))
      assert_equal [david], relation.to_a
    }

    assert_queries(1) {
      relation = Author.where("id in (?)", Author.where(id: david).select(:id))
      assert_equal [david], relation.to_a
    }

    assert_queries(1) do
      relation = Author.where("id in (:author_ids)", author_ids: Author.where(id: david).select(:id))
      assert_equal [david], relation.to_a
    end
  end

  def test_find_all_using_where_with_relation_with_bound_values
    david = authors(:david)
    davids_posts = david.posts.order(:id).to_a

    assert_queries(1) do
      relation = Post.where(id: david.posts.select(:id))
      assert_equal davids_posts, relation.order(:id).to_a
    end

    assert_queries(1) do
      relation = Post.where("id in (?)", david.posts.select(:id))
      assert_equal davids_posts, relation.order(:id).to_a, "should process Relation as bind variables"
    end

    assert_queries(1) do
      relation = Post.where("id in (:post_ids)", post_ids: david.posts.select(:id))
      assert_equal davids_posts, relation.order(:id).to_a, "should process Relation as named bind variables"
    end
  end

  def test_find_all_using_where_with_relation_and_alternate_primary_key
    cool_first = minivans(:cool_first)
    # switching the lines below would succeed in current rails
    # assert_queries(2) {
    assert_queries(1) {
      relation = Minivan.where(minivan_id: Minivan.where(name: cool_first.name))
      assert_equal [cool_first], relation.to_a
    }
  end

  def test_find_all_using_where_with_relation_does_not_alter_select_values
    david = authors(:david)

    subquery = Author.where(id: david.id)

    assert_queries(1) {
      relation = Author.where(id: subquery)
      assert_equal [david], relation.to_a
    }

    assert_equal 0, subquery.select_values.size
  end

  def test_find_all_using_where_with_relation_with_joins
    david = authors(:david)
    assert_queries(1) {
      relation = Author.where(id: Author.joins(:posts).where(id: david.id))
      assert_equal [david], relation.to_a
    }
  end

  def test_find_all_using_where_with_relation_with_select_to_build_subquery
    david = authors(:david)
    assert_queries(1) {
      relation = Author.where(name: Author.where(id: david.id).select(:name))
      assert_equal [david], relation.to_a
    }
  end

  def test_exists
    davids = Author.where(name: "David")
    assert davids.exists?
    assert davids.exists?(authors(:david).id)
    assert ! davids.exists?(authors(:mary).id)
    assert ! davids.exists?("42")
    assert ! davids.exists?(42)
    assert ! davids.exists?(davids.new.id)

    fake  = Author.where(name: "fake author")
    assert ! fake.exists?
    assert ! fake.exists?(authors(:david).id)
  end

  def test_exists_uses_existing_scope
    post = authors(:david).posts.first
    authors = Author.includes(:posts).where(name: "David", posts: { id: post.id })
    assert authors.exists?(authors(:david).id)
  end

  def test_any_with_scope_on_hash_includes
    post = authors(:david).posts.first
    categories = Categorization.includes(author: :posts).where(posts: { id: post.id })
    assert categories.exists?
  end

  def test_last
    authors = Author.all
    assert_equal authors(:bob), authors.last
  end

  def test_destroy_all
    davids = Author.where(name: "David")

    # Force load
    assert_equal [authors(:david)], davids.to_a
    assert davids.loaded?

    assert_difference("Author.count", -1) { davids.destroy_all }

    assert_equal [], davids.to_a
    assert davids.loaded?
  end

  def test_destroy_all_with_conditions_is_deprecated
    assert_deprecated do
      assert_difference("Author.count", -1) { Author.destroy_all(name: "David") }
    end
  end

  def test_delete_all
    davids = Author.where(name: "David")

    assert_difference("Author.count", -1) { davids.delete_all }
    assert ! davids.loaded?
  end

  def test_delete_all_with_conditions_is_deprecated
    assert_deprecated do
      assert_difference("Author.count", -1) { Author.delete_all(name: "David") }
    end
  end

  def test_delete_all_loaded
    davids = Author.where(name: "David")

    # Force load
    assert_equal [authors(:david)], davids.to_a
    assert davids.loaded?

    assert_difference("Author.count", -1) { davids.delete_all }

    assert_equal [], davids.to_a
    assert davids.loaded?
  end

  def test_delete_all_with_unpermitted_relation_raises_error
    assert_raises(ActiveRecord::ActiveRecordError) { Author.limit(10).delete_all }
    assert_raises(ActiveRecord::ActiveRecordError) { Author.distinct.delete_all }
    assert_raises(ActiveRecord::ActiveRecordError) { Author.group(:name).delete_all }
    assert_raises(ActiveRecord::ActiveRecordError) { Author.having("SUM(id) < 3").delete_all }
    assert_raises(ActiveRecord::ActiveRecordError) { Author.offset(10).delete_all }
  end

  def test_select_with_aggregates
    posts = Post.select(:title, :body)

    assert_equal 11, posts.count(:all)
    assert_equal 11, posts.size
    assert posts.any?
    assert posts.many?
    assert_not posts.empty?
  end

  def test_select_takes_a_variable_list_of_args
    david = developers(:david)

    developer = Developer.where(id: david.id).select(:name, :salary).first
    assert_equal david.name, developer.name
    assert_equal david.salary, developer.salary
  end

  def test_select_takes_an_aliased_attribute
    first = topics(:first)

    topic = Topic.where(id: first.id).select(:heading).first
    assert_equal first.heading, topic.heading
  end

  def test_select_argument_error
    assert_raises(ArgumentError) { Developer.select }
  end

  def test_count
    posts = Post.all

    assert_equal 11, posts.count
    assert_equal 11, posts.count(:all)
    assert_equal 11, posts.count(:id)

    assert_equal 1, posts.where("comments_count > 1").count
    assert_equal 9, posts.where(comments_count: 0).count
  end

  def test_count_with_block
    posts = Post.all
    assert_equal 10, posts.count { |p| p.comments_count.even? }
  end

  def test_count_on_association_relation
    author = Author.last
    another_author = Author.first
    posts = Post.where(author_id: author.id)

    assert_equal author.posts.where(author_id: author.id).size, posts.count

    assert_equal 0, author.posts.where(author_id: another_author.id).size
    assert author.posts.where(author_id: another_author.id).empty?
  end

  def test_count_with_distinct
    posts = Post.all

    assert_equal 3, posts.distinct(true).count(:comments_count)
    assert_equal 11, posts.distinct(false).count(:comments_count)

    assert_equal 3, posts.distinct(true).select(:comments_count).count
    assert_equal 11, posts.distinct(false).select(:comments_count).count
  end

  def test_update_all_with_scope
    tag = Tag.first
    Post.tagged_with(tag.id).update_all title: "rofl"
    list = Post.tagged_with(tag.id).all.to_a
    assert_operator list.length, :>, 0
    list.each { |post| assert_equal "rofl", post.title }
  end

  def test_count_explicit_columns
    Post.update_all(comments_count: nil)
    posts = Post.all

    assert_equal [0], posts.select("comments_count").where("id is not null").group("id").order("id").count.values.uniq
    assert_equal 0, posts.where("id is not null").select("comments_count").count

    assert_equal 11, posts.select("comments_count").count("id")
    assert_equal 0, posts.select("comments_count").count
    assert_equal 0, posts.count(:comments_count)
    assert_equal 0, posts.count("comments_count")
  end

  def test_multiple_selects
    post = Post.all.select("comments_count").select("title").order("id ASC").first
    assert_equal "Welcome to the weblog", post.title
    assert_equal 2, post.comments_count
  end

  def test_size
    posts = Post.all

    assert_queries(1) { assert_equal 11, posts.size }
    assert ! posts.loaded?

    best_posts = posts.where(comments_count: 0)
    best_posts.to_a # force load
    assert_no_queries { assert_equal 9, best_posts.size }
  end

  def test_size_with_limit
    posts = Post.limit(10)

    assert_queries(1) { assert_equal 10, posts.size }
    assert ! posts.loaded?

    best_posts = posts.where(comments_count: 0)
    best_posts.to_a # force load
    assert_no_queries { assert_equal 9, best_posts.size }
  end

  def test_size_with_zero_limit
    posts = Post.limit(0)

    assert_no_queries { assert_equal 0, posts.size }
    assert ! posts.loaded?

    posts.to_a # force load
    assert_no_queries { assert_equal 0, posts.size }
  end

  def test_empty_with_zero_limit
    posts = Post.limit(0)

    assert_no_queries { assert_equal true, posts.empty? }
    assert ! posts.loaded?
  end

  def test_count_complex_chained_relations
    posts = Post.select("comments_count").where("id is not null").group("author_id").where("comments_count > 0")

    expected = { 1 => 2 }
    assert_equal expected, posts.count
  end

  def test_empty
    posts = Post.all

    assert_queries(1) { assert_equal false, posts.empty? }
    assert ! posts.loaded?

    no_posts = posts.where(title: "")
    assert_queries(1) { assert_equal true, no_posts.empty? }
    assert ! no_posts.loaded?

    best_posts = posts.where(comments_count: 0)
    best_posts.to_a # force load
    assert_no_queries { assert_equal false, best_posts.empty? }
  end

  def test_empty_complex_chained_relations
    posts = Post.select("comments_count").where("id is not null").group("author_id").where("comments_count > 0")

    assert_queries(1) { assert_equal false, posts.empty? }
    assert ! posts.loaded?

    no_posts = posts.where(title: "")
    assert_queries(1) { assert_equal true, no_posts.empty? }
    assert ! no_posts.loaded?
  end

  def test_any
    posts = Post.all

    # This test was failing when run on its own (as opposed to running the entire suite).
    # The second line in the assert_queries block was causing visit_Arel_Attributes_Attribute
    # in Arel::Visitors::ToSql to trigger a SHOW TABLES query. Running that line here causes
    # the SHOW TABLES result to be cached so we don't have to do it again in the block.
    #
    # This is obviously a rubbish fix but it's the best I can come up with for now...
    posts.where(id: nil).any?

    assert_queries(3) do
      assert posts.any? # Uses COUNT()
      assert ! posts.where(id: nil).any?

      assert posts.any? { |p| p.id > 0 }
      assert ! posts.any? { |p| p.id <= 0 }
    end

    assert posts.loaded?
  end

  def test_many
    posts = Post.all

    assert_queries(2) do
      assert posts.many? # Uses COUNT()
      assert posts.many? { |p| p.id > 0 }
      assert ! posts.many? { |p| p.id < 2 }
    end

    assert posts.loaded?
  end

  def test_many_with_limits
    posts = Post.all

    assert posts.many?
    assert ! posts.limit(1).many?
  end

  def test_none?
    posts = Post.all
    assert_queries(1) do
      assert ! posts.none? # Uses COUNT()
    end

    assert ! posts.loaded?

    assert_queries(1) do
      assert posts.none? { |p| p.id < 0 }
      assert ! posts.none? { |p| p.id == 1 }
    end

    assert posts.loaded?
  end

  def test_one
    posts = Post.all
    assert_queries(1) do
      assert ! posts.one? # Uses COUNT()
    end

    assert ! posts.loaded?

    assert_queries(1) do
      assert ! posts.one? { |p| p.id < 3 }
      assert posts.one? { |p| p.id == 1 }
    end

    assert posts.loaded?
  end

  def test_to_a_should_dup_target
    posts = Post.all

    original_size = posts.size
    removed = posts.to_a.pop

    assert_equal original_size, posts.size
    assert_includes posts.to_a, removed
  end

  def test_build
    posts = Post.all

    post = posts.new
    assert_kind_of Post, post
  end

  def test_scoped_build
    posts = Post.where(title: "You told a lie")

    post = posts.new
    assert_kind_of Post, post
    assert_equal "You told a lie", post.title
  end

  def test_create
    birds = Bird.all

    sparrow = birds.create
    assert_kind_of Bird, sparrow
    assert !sparrow.persisted?

    hen = birds.where(name: "hen").create
    assert hen.persisted?
    assert_equal "hen", hen.name
  end

  def test_create_bang
    birds = Bird.all

    assert_raises(ActiveRecord::RecordInvalid) { birds.create! }

    hen = birds.where(name: "hen").create!
    assert_kind_of Bird, hen
    assert hen.persisted?
    assert_equal "hen", hen.name
  end

  def test_first_or_create
    parrot = Bird.where(color: "green").first_or_create(name: "parrot")
    assert_kind_of Bird, parrot
    assert parrot.persisted?
    assert_equal "parrot", parrot.name
    assert_equal "green", parrot.color

    same_parrot = Bird.where(color: "green").first_or_create(name: "parakeet")
    assert_kind_of Bird, same_parrot
    assert same_parrot.persisted?
    assert_equal parrot, same_parrot
  end

  def test_first_or_create_with_no_parameters
    parrot = Bird.where(color: "green").first_or_create
    assert_kind_of Bird, parrot
    assert !parrot.persisted?
    assert_equal "green", parrot.color
  end

  def test_first_or_create_with_block
    parrot = Bird.where(color: "green").first_or_create { |bird| bird.name = "parrot" }
    assert_kind_of Bird, parrot
    assert parrot.persisted?
    assert_equal "green", parrot.color
    assert_equal "parrot", parrot.name

    same_parrot = Bird.where(color: "green").first_or_create { |bird| bird.name = "parakeet" }
    assert_equal parrot, same_parrot
  end

  def test_first_or_create_with_array
    several_green_birds = Bird.where(color: "green").first_or_create([{ name: "parrot" }, { name: "parakeet" }])
    assert_kind_of Array, several_green_birds
    several_green_birds.each { |bird| assert bird.persisted? }

    same_parrot = Bird.where(color: "green").first_or_create([{ name: "hummingbird" }, { name: "macaw" }])
    assert_kind_of Bird, same_parrot
    assert_equal several_green_birds.first, same_parrot
  end

  def test_first_or_create_bang_with_valid_options
    parrot = Bird.where(color: "green").first_or_create!(name: "parrot")
    assert_kind_of Bird, parrot
    assert parrot.persisted?
    assert_equal "parrot", parrot.name
    assert_equal "green", parrot.color

    same_parrot = Bird.where(color: "green").first_or_create!(name: "parakeet")
    assert_kind_of Bird, same_parrot
    assert same_parrot.persisted?
    assert_equal parrot, same_parrot
  end

  def test_first_or_create_bang_with_invalid_options
    assert_raises(ActiveRecord::RecordInvalid) { Bird.where(color: "green").first_or_create!(pirate_id: 1) }
  end

  def test_first_or_create_bang_with_no_parameters
    assert_raises(ActiveRecord::RecordInvalid) { Bird.where(color: "green").first_or_create! }
  end

  def test_first_or_create_bang_with_valid_block
    parrot = Bird.where(color: "green").first_or_create! { |bird| bird.name = "parrot" }
    assert_kind_of Bird, parrot
    assert parrot.persisted?
    assert_equal "green", parrot.color
    assert_equal "parrot", parrot.name

    same_parrot = Bird.where(color: "green").first_or_create! { |bird| bird.name = "parakeet" }
    assert_equal parrot, same_parrot
  end

  def test_first_or_create_bang_with_invalid_block
    assert_raise(ActiveRecord::RecordInvalid) do
      Bird.where(color: "green").first_or_create! { |bird| bird.pirate_id = 1 }
    end
  end

  def test_first_or_create_with_valid_array
    several_green_birds = Bird.where(color: "green").first_or_create!([{ name: "parrot" }, { name: "parakeet" }])
    assert_kind_of Array, several_green_birds
    several_green_birds.each { |bird| assert bird.persisted? }

    same_parrot = Bird.where(color: "green").first_or_create!([{ name: "hummingbird" }, { name: "macaw" }])
    assert_kind_of Bird, same_parrot
    assert_equal several_green_birds.first, same_parrot
  end

  def test_first_or_create_with_invalid_array
    assert_raises(ActiveRecord::RecordInvalid) { Bird.where(color: "green").first_or_create!([ { name: "parrot" }, { pirate_id: 1 } ]) }
  end

  def test_first_or_initialize
    parrot = Bird.where(color: "green").first_or_initialize(name: "parrot")
    assert_kind_of Bird, parrot
    assert !parrot.persisted?
    assert parrot.valid?
    assert parrot.new_record?
    assert_equal "parrot", parrot.name
    assert_equal "green", parrot.color
  end

  def test_first_or_initialize_with_no_parameters
    parrot = Bird.where(color: "green").first_or_initialize
    assert_kind_of Bird, parrot
    assert !parrot.persisted?
    assert !parrot.valid?
    assert parrot.new_record?
    assert_equal "green", parrot.color
  end

  def test_first_or_initialize_with_block
    parrot = Bird.where(color: "green").first_or_initialize { |bird| bird.name = "parrot" }
    assert_kind_of Bird, parrot
    assert !parrot.persisted?
    assert parrot.valid?
    assert parrot.new_record?
    assert_equal "green", parrot.color
    assert_equal "parrot", parrot.name
  end

  def test_find_or_create_by
    assert_nil Bird.find_by(name: "bob")

    bird = Bird.find_or_create_by(name: "bob")
    assert bird.persisted?

    assert_equal bird, Bird.find_or_create_by(name: "bob")
  end

  def test_find_or_create_by_with_create_with
    assert_nil Bird.find_by(name: "bob")

    bird = Bird.create_with(color: "green").find_or_create_by(name: "bob")
    assert bird.persisted?
    assert_equal "green", bird.color

    assert_equal bird, Bird.create_with(color: "blue").find_or_create_by(name: "bob")
  end

  def test_find_or_create_by!
    assert_raises(ActiveRecord::RecordInvalid) { Bird.find_or_create_by!(color: "green") }
  end

  def test_find_or_initialize_by
    assert_nil Bird.find_by(name: "bob")

    bird = Bird.find_or_initialize_by(name: "bob")
    assert bird.new_record?
    bird.save!

    assert_equal bird, Bird.find_or_initialize_by(name: "bob")
  end

  def test_explicit_create_scope
    hens = Bird.where(name: "hen")
    assert_equal "hen", hens.new.name

    hens = hens.create_with(name: "cock")
    assert_equal "cock", hens.new.name
  end

  def test_except
    relation = Post.where(author_id: 1).order("id ASC").limit(1)
    assert_equal [posts(:welcome)], relation.to_a

    author_posts = relation.except(:order, :limit)
    assert_equal Post.where(author_id: 1).to_a, author_posts.to_a

    all_posts = relation.except(:where, :order, :limit)
    assert_equal Post.all, all_posts
  end

  def test_only
    relation = Post.where(author_id: 1).order("id ASC").limit(1)
    assert_equal [posts(:welcome)], relation.to_a

    author_posts = relation.only(:where)
    assert_equal Post.where(author_id: 1).to_a, author_posts.to_a

    all_posts = relation.only(:limit)
    assert_equal Post.limit(1).to_a, all_posts.to_a
  end

  def test_anonymous_extension
    relation = Post.where(author_id: 1).order("id ASC").extending do
      def author
        "lifo"
      end
    end

    assert_equal "lifo", relation.author
    assert_equal "lifo", relation.limit(1).author
  end

  def test_named_extension
    relation = Post.where(author_id: 1).order("id ASC").extending(Post::NamedExtension)
    assert_equal "lifo", relation.author
    assert_equal "lifo", relation.limit(1).author
  end

  def test_order_by_relation_attribute
    assert_equal Post.order(Post.arel_table[:title]).to_a, Post.order("title").to_a
  end

  def test_default_scope_order_with_scope_order
    assert_equal "zyke", CoolCar.order_using_new_style.limit(1).first.name
    assert_equal "zyke", FastCar.order_using_new_style.limit(1).first.name
  end

  def test_order_using_scoping
    car1 = CoolCar.order("id DESC").scoping do
      CoolCar.all.merge!(order: "id asc").first
    end
    assert_equal "zyke", car1.name

    car2 = FastCar.order("id DESC").scoping do
      FastCar.all.merge!(order: "id asc").first
    end
    assert_equal "zyke", car2.name
  end

  def test_unscoped_block_style
    assert_equal "honda", CoolCar.unscoped { CoolCar.order_using_new_style.limit(1).first.name }
    assert_equal "honda", FastCar.unscoped { FastCar.order_using_new_style.limit(1).first.name }
  end

  def test_intersection_with_array
    relation = Author.where(name: "David")
    rails_author = relation.first

    assert_equal [rails_author], [rails_author] & relation
    assert_equal [rails_author], relation & [rails_author]
  end

  def test_primary_key
    assert_equal "id", Post.all.primary_key
  end

  def test_ordering_with_extra_spaces
    assert_equal authors(:david), Author.order("id DESC , name DESC").last
  end

  def test_update_all_with_blank_argument
    assert_raises(ArgumentError) { Comment.update_all({}) }
  end

  def test_update_all_with_joins
    comments = Comment.joins(:post).where("posts.id" => posts(:welcome).id)
    count    = comments.count

    assert_equal count, comments.update_all(post_id: posts(:thinking).id)
    assert_equal posts(:thinking), comments(:greetings).post
  end

  def test_update_all_with_joins_and_limit
    comments = Comment.joins(:post).where("posts.id" => posts(:welcome).id).limit(1)
    assert_equal 1, comments.update_all(post_id: posts(:thinking).id)
  end

  def test_update_all_with_joins_and_limit_and_order
    comments = Comment.joins(:post).where("posts.id" => posts(:welcome).id).order("comments.id").limit(1)
    assert_equal 1, comments.update_all(post_id: posts(:thinking).id)
    assert_equal posts(:thinking), comments(:greetings).post
    assert_equal posts(:welcome),  comments(:more_greetings).post
  end

  def test_update_all_with_joins_and_offset
    all_comments = Comment.joins(:post).where("posts.id" => posts(:welcome).id)
    count        = all_comments.count
    comments     = all_comments.offset(1)

    assert_equal count - 1, comments.update_all(post_id: posts(:thinking).id)
  end

  def test_update_all_with_joins_and_offset_and_order
    all_comments = Comment.joins(:post).where("posts.id" => posts(:welcome).id).order("posts.id", "comments.id")
    count        = all_comments.count
    comments     = all_comments.offset(1)

    assert_equal count - 1, comments.update_all(post_id: posts(:thinking).id)
    assert_equal posts(:thinking), comments(:more_greetings).post
    assert_equal posts(:welcome),  comments(:greetings).post
  end

  def test_update_on_relation
    topic1 = TopicWithCallbacks.create! title: "arel", author_name: nil
    topic2 = TopicWithCallbacks.create! title: "activerecord", author_name: nil
    topics = TopicWithCallbacks.where(id: [topic1.id, topic2.id])
    topics.update(title: "adequaterecord")

    assert_equal "adequaterecord", topic1.reload.title
    assert_equal "adequaterecord", topic2.reload.title
    # Testing that the before_update callbacks have run
    assert_equal "David", topic1.reload.author_name
    assert_equal "David", topic2.reload.author_name
  end

  def test_update_on_relation_passing_active_record_object_is_deprecated
    topic = Topic.create!(title: "Foo", author_name: nil)
    assert_deprecated(/update/) do
      Topic.where(id: topic.id).update(topic, title: "Bar")
    end
  end

  def test_distinct
    tag1 = Tag.create(name: "Foo")
    tag2 = Tag.create(name: "Foo")

    query = Tag.select(:name).where(id: [tag1.id, tag2.id])

    assert_equal ["Foo", "Foo"], query.map(&:name)
    assert_sql(/DISTINCT/) do
      assert_equal ["Foo"], query.distinct.map(&:name)
      assert_deprecated { assert_equal ["Foo"], query.uniq.map(&:name) }
    end
    assert_sql(/DISTINCT/) do
      assert_equal ["Foo"], query.distinct(true).map(&:name)
      assert_deprecated { assert_equal ["Foo"], query.uniq(true).map(&:name) }
    end
    assert_equal ["Foo", "Foo"], query.distinct(true).distinct(false).map(&:name)

    assert_deprecated do
      assert_equal ["Foo", "Foo"], query.uniq(true).uniq(false).map(&:name)
    end
  end

  def test_doesnt_add_having_values_if_options_are_blank
    scope = Post.having("")
    assert scope.having_clause.empty?

    scope = Post.having([])
    assert scope.having_clause.empty?
  end

  def test_having_with_binds_for_both_where_and_having
    post = Post.first
    having_then_where = Post.having(id: post.id).where(title: post.title).group(:id)
    where_then_having = Post.where(title: post.title).having(id: post.id).group(:id)

    assert_equal [post], having_then_where
    assert_equal [post], where_then_having
  end

  def test_multiple_where_and_having_clauses
    post = Post.first
    having_then_where = Post.having(id: post.id).where(title: post.title)
      .having(id: post.id).where(title: post.title).group(:id)

    assert_equal [post], having_then_where
  end

  def test_grouping_by_column_with_reserved_name
    assert_equal [], Possession.select(:where).group(:where).to_a
  end

  def test_references_triggers_eager_loading
    scope = Post.includes(:comments)
    assert !scope.eager_loading?
    assert scope.references(:comments).eager_loading?
  end

  def test_references_doesnt_trigger_eager_loading_if_reference_not_included
    scope = Post.references(:comments)
    assert !scope.eager_loading?
  end

  def test_automatically_added_where_references
    scope = Post.where(comments: { body: "Bla" })
    assert_equal ["comments"], scope.references_values

    scope = Post.where("comments.body" => "Bla")
    assert_equal ["comments"], scope.references_values
  end

  def test_automatically_added_where_not_references
    scope = Post.where.not(comments: { body: "Bla" })
    assert_equal ["comments"], scope.references_values

    scope = Post.where.not("comments.body" => "Bla")
    assert_equal ["comments"], scope.references_values
  end

  def test_automatically_added_having_references
    scope = Post.having(comments: { body: "Bla" })
    assert_equal ["comments"], scope.references_values

    scope = Post.having("comments.body" => "Bla")
    assert_equal ["comments"], scope.references_values
  end

  def test_automatically_added_order_references
    scope = Post.order("comments.body")
    assert_equal ["comments"], scope.references_values

    scope = Post.order("comments.body", "yaks.body")
    assert_equal ["comments", "yaks"], scope.references_values

    # Don't infer yaks, let's not go down that road again...
    scope = Post.order("comments.body, yaks.body")
    assert_equal ["comments"], scope.references_values

    scope = Post.order("comments.body asc")
    assert_equal ["comments"], scope.references_values

    scope = Post.order("foo(comments.body)")
    assert_equal [], scope.references_values
  end

  def test_automatically_added_reorder_references
    scope = Post.reorder("comments.body")
    assert_equal %w(comments), scope.references_values

    scope = Post.reorder("comments.body", "yaks.body")
    assert_equal %w(comments yaks), scope.references_values

    # Don't infer yaks, let's not go down that road again...
    scope = Post.reorder("comments.body, yaks.body")
    assert_equal %w(comments), scope.references_values

    scope = Post.reorder("comments.body asc")
    assert_equal %w(comments), scope.references_values

    scope = Post.reorder("foo(comments.body)")
    assert_equal [], scope.references_values
  end

  def test_order_with_reorder_nil_removes_the_order
    relation = Post.order(:title).reorder(nil)

    assert_nil relation.order_values.first
  end

  def test_reverse_order_with_reorder_nil_removes_the_order
    relation = Post.order(:title).reverse_order.reorder(nil)

    assert_nil relation.order_values.first
  end

  def test_presence
    topics = Topic.all

    # the first query is triggered because there are no topics yet.
    assert_queries(1) { assert topics.present? }

    # checking if there are topics is used before you actually display them,
    # thus it shouldn't invoke an extra count query.
    assert_no_queries { assert topics.present? }
    assert_no_queries { assert !topics.blank? }

    # shows count of topics and loops after loading the query should not trigger extra queries either.
    assert_no_queries { topics.size }
    assert_no_queries { topics.length }
    assert_no_queries { topics.each }

    # count always trigger the COUNT query.
    assert_queries(1) { topics.count }

    assert topics.loaded?
  end

  test "find_by with hash conditions returns the first matching record" do
    assert_equal posts(:eager_other), Post.order(:id).find_by(author_id: 2)
  end

  test "find_by with non-hash conditions returns the first matching record" do
    assert_equal posts(:eager_other), Post.order(:id).find_by("author_id = 2")
  end

  test "find_by with multi-arg conditions returns the first matching record" do
    assert_equal posts(:eager_other), Post.order(:id).find_by("author_id = ?", 2)
  end

  test "find_by returns nil if the record is missing" do
    assert_equal nil, Post.all.find_by("1 = 0")
  end

  test "find_by doesn't have implicit ordering" do
    assert_sql(/^((?!ORDER).)*$/) { Post.all.find_by(author_id: 2) }
  end

  test "find_by requires at least one argument" do
    assert_raises(ArgumentError) { Post.all.find_by }
  end

  test "find_by! with hash conditions returns the first matching record" do
    assert_equal posts(:eager_other), Post.order(:id).find_by!(author_id: 2)
  end

  test "find_by! with non-hash conditions returns the first matching record" do
    assert_equal posts(:eager_other), Post.order(:id).find_by!("author_id = 2")
  end

  test "find_by! with multi-arg conditions returns the first matching record" do
    assert_equal posts(:eager_other), Post.order(:id).find_by!("author_id = ?", 2)
  end

  test "find_by! doesn't have implicit ordering" do
    assert_sql(/^((?!ORDER).)*$/) { Post.all.find_by!(author_id: 2) }
  end

  test "find_by! raises RecordNotFound if the record is missing" do
    assert_raises(ActiveRecord::RecordNotFound) do
      Post.all.find_by!("1 = 0")
    end
  end

  test "find_by! requires at least one argument" do
    assert_raises(ArgumentError) { Post.all.find_by! }
  end

  test "loaded relations cannot be mutated by multi value methods" do
    relation = Post.all
    relation.to_a

    assert_raises(ActiveRecord::ImmutableRelation) do
      relation.where! "foo"
    end
  end

  test "loaded relations cannot be mutated by single value methods" do
    relation = Post.all
    relation.to_a

    assert_raises(ActiveRecord::ImmutableRelation) do
      relation.limit! 5
    end
  end

  test "loaded relations cannot be mutated by merge!" do
    relation = Post.all
    relation.to_a

    assert_raises(ActiveRecord::ImmutableRelation) do
      relation.merge! where: "foo"
    end
  end

  test "loaded relations cannot be mutated by extending!" do
    relation = Post.all
    relation.to_a

    assert_raises(ActiveRecord::ImmutableRelation) do
      relation.extending! Module.new
    end
  end

  test "relations with cached arel can't be mutated [internal API]" do
    relation = Post.all
    relation.count

    assert_raises(ActiveRecord::ImmutableRelation) { relation.limit!(5) }
    assert_raises(ActiveRecord::ImmutableRelation) { relation.where!("1 = 2") }
  end

  test "relations show the records in #inspect" do
    relation = Post.limit(2)
    assert_equal "#<ActiveRecord::Relation [#{Post.limit(2).map(&:inspect).join(', ')}]>", relation.inspect
  end

  test "relations limit the records in #inspect at 10" do
    relation = Post.limit(11)
    assert_equal "#<ActiveRecord::Relation [#{Post.limit(10).map(&:inspect).join(', ')}, ...]>", relation.inspect
  end

  test "already-loaded relations don't perform a new query in #inspect" do
    relation = Post.limit(2)
    relation.to_a

    expected = "#<ActiveRecord::Relation [#{Post.limit(2).map(&:inspect).join(', ')}]>"

    assert_no_queries do
      assert_equal expected, relation.inspect
    end
  end

  test "using a custom table affects the wheres" do
    table_alias = Post.arel_table.alias("omg_posts")

    table_metadata = ActiveRecord::TableMetadata.new(Post, table_alias)
    predicate_builder = ActiveRecord::PredicateBuilder.new(table_metadata)
    relation = ActiveRecord::Relation.new(Post, table_alias, predicate_builder)
    relation.where!(foo: "bar")

    node = relation.arel.constraints.first.grep(Arel::Attributes::Attribute).first
    assert_equal table_alias, node.relation
  end

  test "#load" do
    relation = Post.all
    assert_queries(1) do
      assert_equal relation, relation.load
    end
    assert_no_queries { relation.to_a }
  end

  test "group with select and includes" do
    authors_count = Post.select("author_id, COUNT(author_id) AS num_posts").
      group("author_id").order("author_id").includes(:author).to_a

    assert_no_queries do
      result = authors_count.map do |post|
        [post.num_posts, post.author.try(:name)]
      end

      expected = [[1, nil], [5, "David"], [3, "Mary"], [2, "Bob"]]
      assert_equal expected, result
    end
  end

  test "joins with select" do
    posts = Post.joins(:author).select("id", "authors.author_address_id").order("posts.id").limit(3)
    assert_equal [1, 2, 4], posts.map(&:id)
    assert_equal [1, 1, 1], posts.map(&:author_address_id)
  end

  test "delegations do not leak to other classes" do
    Topic.all.by_lifo
    assert Topic.all.class.method_defined?(:by_lifo)
    assert !Post.all.respond_to?(:by_lifo)
  end

  def test_unscope_removes_binds
    left  = Post.where(id: Arel::Nodes::BindParam.new)
    column = Post.columns_hash["id"]
    left.bind_values += [[column, 20]]

    relation = left.unscope(where: :id)
    assert_equal [], relation.bind_values
  end

  def test_merging_removes_rhs_bind_parameters
    left  = Post.where(id: 20)
    right   = Post.where(id: [1,2,3,4])

    merged = left.merge(right)
    assert_equal [], merged.bind_values
  end

  def test_merging_keeps_lhs_bind_parameters
    binds = [ActiveRecord::Relation::QueryAttribute.new("id", 20, Post.type_for_attribute("id"))]

    right  = Post.where(id: 20)
    left   = Post.where(id: 10)

    merged = left.merge(right)
    assert_equal binds, merged.bound_attributes
  end

  def test_merging_reorders_bind_params
    post  = Post.first
    right = Post.where(id: post.id)
    left  = Post.where(title: post.title)

    merged = left.merge(right)
    assert_equal post, merged.first
  end

  def test_relation_join_method
    assert_equal "Thank you for the welcome,Thank you again for the welcome", Post.first.comments.join(",")
  end

  def test_connection_adapters_can_reorder_binds
    posts = Post.limit(1).offset(2)

    stubbed_connection = Post.connection.dup
    def stubbed_connection.combine_bind_parameters(**kwargs)
      offset = kwargs[:offset]
      kwargs[:offset] = kwargs[:limit]
      kwargs[:limit] = offset
      super(**kwargs)
    end

    posts.define_singleton_method(:connection) do
      stubbed_connection
    end

    assert_equal 2, posts.to_a.length
  end
end