1
0
Fork 0
mirror of https://github.com/rails/rails.git synced 2022-11-09 12:12:34 -05:00
rails--rails/activerecord/test/cases/associations_test.rb
Dinah Shi 2a3f1757dd Add available_records argument to Associations::Preloader
Sometimes when we are preloading associations on records, we already have
the association objects loaded in-memory. But the Preloader will go to the
database to fetch them anyways because there is no way to tell it about
these loaded objects. This PR adds a new `available_records` argument to
supply the Preloader with a set of in-memory records that it can use to
fill associations without making a database query.

`available_records` is an array of ActiveRecord::Base objects. Mixed
models are supported. Preloader will use these records to try to fill the
requested associations before querying the database. This can save database
queries by reusing in-memory objects.

The optimization is only applied to single associations (i.e. :belongs_to,
:has_one) as we must query the database to do an exhaustive lookup for
collections (i.e. :has_many). It also requires the query to have no scopes
as scopes can filter associations even if they are already in memory.

```ruby
comment = Comment.last
post = Post.find_by(id: comment.post_id)
all_authors = Author.all.to_a

Preloader.new([comment], [:post, :author]).call

Preloader.new([comment], [:post, :author], available_records: [post, all_authors]).call
```

Co-Authored-By: John Hawthorn <john@hawthorn.email>
2021-07-14 08:44:03 -04:00

967 lines
32 KiB
Ruby

# 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
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
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_legacy_preload_with_scope
post = posts(:welcome)
assert_deprecated do
preloader = ActiveRecord::Associations::Preloader.new
preloader.preload([post], :comments, Comment.where(body: "Thank you for the welcome"))
end
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_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_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)
assert_queries(9) do
preloader = ActiveRecord::Associations::Preloader.new(records: [mary], associations: { similar_posts: :comments, favorite_authors: { similar_posts: :comments } })
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
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_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_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
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