1 files changed, 676 insertions, 0 deletions
diff --git a/activerecord/test/cases/batches_test.rb b/activerecord/test/cases/batches_test.rb
new file mode 100644
index 0000000000..53c1e61ad1
--- /dev/null
+++ b/activerecord/test/cases/batches_test.rb
@@ -0,0 +1,676 @@
+# frozen_string_literal: true
+
+require "cases/helper"
+require "models/comment"
+require "models/post"
+require "models/subscriber"
+
+class EachTest < ActiveRecord::TestCase
+  fixtures :posts, :subscribers
+
+  def setup
+    @posts = Post.order("id asc")
+    @total = Post.count
+    Post.count("id") # preheat arel's table cache
+  end
+
+  def test_each_should_execute_one_query_per_batch
+    assert_queries(@total + 1) do
+      Post.find_each(batch_size: 1) do |post|
+        assert_kind_of Post, post
+      end
+    end
+  end
+
+  def test_each_should_not_return_query_chain_and_execute_only_one_query
+    assert_queries(1) do
+      result = Post.find_each(batch_size: 100000) {}
+      assert_nil result
+    end
+  end
+
+  def test_each_should_return_an_enumerator_if_no_block_is_present
+    assert_queries(1) do
+      Post.find_each(batch_size: 100000).with_index do |post, index|
+        assert_kind_of Post, post
+        assert_kind_of Integer, index
+      end
+    end
+  end
+
+  def test_each_should_return_a_sized_enumerator
+    assert_equal 11, Post.find_each(batch_size: 1).size
+    assert_equal 5, Post.find_each(batch_size:  2, start: 7).size
+    assert_equal 11, Post.find_each(batch_size: 10_000).size
+  end
+
+  def test_each_enumerator_should_execute_one_query_per_batch
+    assert_queries(@total + 1) do
+      Post.find_each(batch_size: 1).with_index do |post, index|
+        assert_kind_of Post, post
+        assert_kind_of Integer, index
+      end
+    end
+  end
+
+  def test_each_should_raise_if_select_is_set_without_id
+    assert_raise(ArgumentError) do
+      Post.select(:title).find_each(batch_size: 1) { |post|
+        flunk "should not call this block"
+      }
+    end
+  end
+
+  def test_each_should_execute_if_id_is_in_select
+    assert_queries(6) do
+      Post.select("id, title, type").find_each(batch_size: 2) do |post|
+        assert_kind_of Post, post
+      end
+    end
+  end
+
+  test "find_each should honor limit if passed a block" do
+    limit = @total - 1
+    total = 0
+
+    Post.limit(limit).find_each do |post|
+      total += 1
+    end
+
+    assert_equal limit, total
+  end
+
+  test "find_each should honor limit if no block is passed" do
+    limit = @total - 1
+    total = 0
+
+    Post.limit(limit).find_each.each do |post|
+      total += 1
+    end
+
+    assert_equal limit, total
+  end
+
+  def test_warn_if_order_scope_is_set
+    assert_called(ActiveRecord::Base.logger, :warn) do
+      Post.order("title").find_each { |post| post }
+    end
+  end
+
+  def test_logger_not_required
+    previous_logger = ActiveRecord::Base.logger
+    ActiveRecord::Base.logger = nil
+    assert_nothing_raised do
+      Post.order("comments_count DESC").find_each { |post| post }
+    end
+  ensure
+    ActiveRecord::Base.logger = previous_logger
+  end
+
+  def test_find_in_batches_should_return_batches
+    assert_queries(@total + 1) do
+      Post.find_in_batches(batch_size: 1) do |batch|
+        assert_kind_of Array, batch
+        assert_kind_of Post, batch.first
+      end
+    end
+  end
+
+  def test_find_in_batches_should_start_from_the_start_option
+    assert_queries(@total) do
+      Post.find_in_batches(batch_size: 1, start: 2) do |batch|
+        assert_kind_of Array, batch
+        assert_kind_of Post, batch.first
+      end
+    end
+  end
+
+  def test_find_in_batches_should_end_at_the_finish_option
+    assert_queries(6) do
+      Post.find_in_batches(batch_size: 1, finish: 5) do |batch|
+        assert_kind_of Array, batch
+        assert_kind_of Post, batch.first
+      end
+    end
+  end
+
+  def test_find_in_batches_shouldnt_execute_query_unless_needed
+    assert_queries(2) do
+      Post.find_in_batches(batch_size: @total) { |batch| assert_kind_of Array, batch }
+    end
+
+    assert_queries(1) do
+      Post.find_in_batches(batch_size: @total + 1) { |batch| assert_kind_of Array, batch }
+    end
+  end
+
+  def test_find_in_batches_should_quote_batch_order
+    c = Post.connection
+    assert_sql(/ORDER BY #{c.quote_table_name('posts')}\.#{c.quote_column_name('id')}/) do
+      Post.find_in_batches(batch_size: 1) do |batch|
+        assert_kind_of Array, batch
+        assert_kind_of Post, batch.first
+      end
+    end
+  end
+
+  def test_find_in_batches_should_not_use_records_after_yielding_them_in_case_original_array_is_modified
+    not_a_post = "not a post".dup
+    def not_a_post.id; end
+    not_a_post.stub(:id, -> { raise StandardError.new("not_a_post had #id called on it") }) do
+      assert_nothing_raised do
+        Post.find_in_batches(batch_size: 1) do |batch|
+          assert_kind_of Array, batch
+          assert_kind_of Post, batch.first
+
+          batch.map! { not_a_post }
+        end
+      end
+    end
+  end
+
+  def test_find_in_batches_should_ignore_the_order_default_scope
+    # First post is with title scope
+    first_post = PostWithDefaultScope.first
+    posts = []
+    PostWithDefaultScope.find_in_batches  do |batch|
+      posts.concat(batch)
+    end
+    # posts.first will be ordered using id only. Title order scope should not apply here
+    assert_not_equal first_post, posts.first
+    assert_equal posts(:welcome).id, posts.first.id
+  end
+
+  def test_find_in_batches_should_error_on_ignore_the_order
+    assert_raise(ArgumentError) do
+      PostWithDefaultScope.find_in_batches(error_on_ignore: true) {}
+    end
+  end
+
+  def test_find_in_batches_should_not_error_if_config_overridden
+    # Set the config option which will be overridden
+    prev = ActiveRecord::Base.error_on_ignored_order
+    ActiveRecord::Base.error_on_ignored_order = true
+    assert_nothing_raised do
+      PostWithDefaultScope.find_in_batches(error_on_ignore: false) {}
+    end
+  ensure
+    # Set back to default
+    ActiveRecord::Base.error_on_ignored_order = prev
+  end
+
+  def test_find_in_batches_should_error_on_config_specified_to_error
+    # Set the config option
+    prev = ActiveRecord::Base.error_on_ignored_order
+    ActiveRecord::Base.error_on_ignored_order = true
+    assert_raise(ArgumentError) do
+      PostWithDefaultScope.find_in_batches() {}
+    end
+  ensure
+    # Set back to default
+    ActiveRecord::Base.error_on_ignored_order = prev
+  end
+
+  def test_find_in_batches_should_not_error_by_default
+    assert_nothing_raised do
+      PostWithDefaultScope.find_in_batches() {}
+    end
+  end
+
+  def test_find_in_batches_should_not_ignore_the_default_scope_if_it_is_other_then_order
+    special_posts_ids = SpecialPostWithDefaultScope.all.map(&:id).sort
+    posts = []
+    SpecialPostWithDefaultScope.find_in_batches do |batch|
+      posts.concat(batch)
+    end
+    assert_equal special_posts_ids, posts.map(&:id)
+  end
+
+  def test_find_in_batches_should_not_modify_passed_options
+    assert_nothing_raised do
+      Post.find_in_batches({ batch_size: 42, start: 1 }.freeze) {}
+    end
+  end
+
+  def test_find_in_batches_should_use_any_column_as_primary_key
+    nick_order_subscribers = Subscriber.order("nick asc")
+    start_nick = nick_order_subscribers.second.nick
+
+    subscribers = []
+    Subscriber.find_in_batches(batch_size: 1, start: start_nick) do |batch|
+      subscribers.concat(batch)
+    end
+
+    assert_equal nick_order_subscribers[1..-1].map(&:id), subscribers.map(&:id)
+  end
+
+  def test_find_in_batches_should_use_any_column_as_primary_key_when_start_is_not_specified
+    assert_queries(Subscriber.count + 1) do
+      Subscriber.find_in_batches(batch_size: 1) do |batch|
+        assert_kind_of Array, batch
+        assert_kind_of Subscriber, batch.first
+      end
+    end
+  end
+
+  def test_find_in_batches_should_return_an_enumerator
+    enum = nil
+    assert_no_queries do
+      enum = Post.find_in_batches(batch_size: 1)
+    end
+    assert_queries(4) do
+      enum.first(4) do |batch|
+        assert_kind_of Array, batch
+        assert_kind_of Post, batch.first
+      end
+    end
+  end
+
+  test "find_in_batches should honor limit if passed a block" do
+    limit = @total - 1
+    total = 0
+
+    Post.limit(limit).find_in_batches do |batch|
+      total += batch.size
+    end
+
+    assert_equal limit, total
+  end
+
+  test "find_in_batches should honor limit if no block is passed" do
+    limit = @total - 1
+    total = 0
+
+    Post.limit(limit).find_in_batches.each do |batch|
+      total += batch.size
+    end
+
+    assert_equal limit, total
+  end
+
+  def test_in_batches_should_not_execute_any_query
+    assert_no_queries do
+      assert_kind_of ActiveRecord::Batches::BatchEnumerator, Post.in_batches(of: 2)
+    end
+  end
+
+  def test_in_batches_should_yield_relation_if_block_given
+    assert_queries(6) do
+      Post.in_batches(of: 2) do |relation|
+        assert_kind_of ActiveRecord::Relation, relation
+      end
+    end
+  end
+
+  def test_in_batches_should_be_enumerable_if_no_block_given
+    assert_queries(6) do
+      Post.in_batches(of: 2).each do |relation|
+        assert_kind_of ActiveRecord::Relation, relation
+      end
+    end
+  end
+
+  def test_in_batches_each_record_should_yield_record_if_block_is_given
+    assert_queries(6) do
+      Post.in_batches(of: 2).each_record do |post|
+        assert post.title.present?
+        assert_kind_of Post, post
+      end
+    end
+  end
+
+  def test_in_batches_each_record_should_return_enumerator_if_no_block_given
+    assert_queries(6) do
+      Post.in_batches(of: 2).each_record.with_index do |post, i|
+        assert post.title.present?
+        assert_kind_of Post, post
+      end
+    end
+  end
+
+  def test_in_batches_each_record_should_be_ordered_by_id
+    ids = Post.order("id ASC").pluck(:id)
+    assert_queries(6) do
+      Post.in_batches(of: 2).each_record.with_index do |post, i|
+        assert_equal ids[i], post.id
+      end
+    end
+  end
+
+  def test_in_batches_update_all_affect_all_records
+    assert_queries(6 + 6) do # 6 selects, 6 updates
+      Post.in_batches(of: 2).update_all(title: "updated-title")
+    end
+    assert_equal Post.all.pluck(:title), ["updated-title"] * Post.count
+  end
+
+  def test_in_batches_delete_all_should_not_delete_records_in_other_batches
+    not_deleted_count = Post.where("id <= 2").count
+    Post.where("id > 2").in_batches(of: 2).delete_all
+    assert_equal 0, Post.where("id > 2").count
+    assert_equal not_deleted_count, Post.count
+  end
+
+  def test_in_batches_should_not_be_loaded
+    Post.in_batches(of: 1) do |relation|
+      assert_not relation.loaded?
+    end
+
+    Post.in_batches(of: 1, load: false) do |relation|
+      assert_not relation.loaded?
+    end
+  end
+
+  def test_in_batches_should_be_loaded
+    Post.in_batches(of: 1, load: true) do |relation|
+      assert relation.loaded?
+    end
+  end
+
+  def test_in_batches_if_not_loaded_executes_more_queries
+    assert_queries(@total + 1) do
+      Post.in_batches(of: 1, load: false) do |relation|
+        assert_not relation.loaded?
+      end
+    end
+  end
+
+  def test_in_batches_should_return_relations
+    assert_queries(@total + 1) do
+      Post.in_batches(of: 1) do |relation|
+        assert_kind_of ActiveRecord::Relation, relation
+      end
+    end
+  end
+
+  def test_in_batches_should_start_from_the_start_option
+    post = Post.order("id ASC").where("id >= ?", 2).first
+    assert_queries(2) do
+      relation = Post.in_batches(of: 1, start: 2).first
+      assert_equal post, relation.first
+    end
+  end
+
+  def test_in_batches_should_end_at_the_finish_option
+    post = Post.order("id DESC").where("id <= ?", 5).first
+    assert_queries(7) do
+      relation = Post.in_batches(of: 1, finish: 5, load: true).reverse_each.first
+      assert_equal post, relation.last
+    end
+  end
+
+  def test_in_batches_shouldnt_execute_query_unless_needed
+    assert_queries(2) do
+      Post.in_batches(of: @total) { |relation| assert_kind_of ActiveRecord::Relation, relation }
+    end
+
+    assert_queries(1) do
+      Post.in_batches(of: @total + 1) { |relation| assert_kind_of ActiveRecord::Relation, relation }
+    end
+  end
+
+  def test_in_batches_should_quote_batch_order
+    c = Post.connection
+    assert_sql(/ORDER BY #{c.quote_table_name('posts')}\.#{c.quote_column_name('id')}/) do
+      Post.in_batches(of: 1) do |relation|
+        assert_kind_of ActiveRecord::Relation, relation
+        assert_kind_of Post, relation.first
+      end
+    end
+  end
+
+  def test_in_batches_should_not_use_records_after_yielding_them_in_case_original_array_is_modified
+    not_a_post = "not a post".dup
+    def not_a_post.id
+      raise StandardError.new("not_a_post had #id called on it")
+    end
+
+    assert_nothing_raised do
+      Post.in_batches(of: 1) do |relation|
+        assert_kind_of ActiveRecord::Relation, relation
+        assert_kind_of Post, relation.first
+
+        relation = [not_a_post] * relation.count
+      end
+    end
+  end
+
+  def test_in_batches_should_not_ignore_default_scope_without_order_statements
+    special_posts_ids = SpecialPostWithDefaultScope.all.map(&:id).sort
+    posts = []
+    SpecialPostWithDefaultScope.in_batches do |relation|
+      posts.concat(relation)
+    end
+    assert_equal special_posts_ids, posts.map(&:id)
+  end
+
+  def test_in_batches_should_not_modify_passed_options
+    assert_nothing_raised do
+      Post.in_batches({ of: 42, start: 1 }.freeze) {}
+    end
+  end
+
+  def test_in_batches_should_use_any_column_as_primary_key
+    nick_order_subscribers = Subscriber.order("nick asc")
+    start_nick = nick_order_subscribers.second.nick
+
+    subscribers = []
+    Subscriber.in_batches(of: 1, start: start_nick) do |relation|
+      subscribers.concat(relation)
+    end
+
+    assert_equal nick_order_subscribers[1..-1].map(&:id), subscribers.map(&:id)
+  end
+
+  def test_in_batches_should_use_any_column_as_primary_key_when_start_is_not_specified
+    assert_queries(Subscriber.count + 1) do
+      Subscriber.in_batches(of: 1, load: true) do |relation|
+        assert_kind_of ActiveRecord::Relation, relation
+        assert_kind_of Subscriber, relation.first
+      end
+    end
+  end
+
+  def test_in_batches_should_return_an_enumerator
+    enum = nil
+    assert_no_queries do
+      enum = Post.in_batches(of: 1)
+    end
+    assert_queries(4) do
+      enum.first(4) do |relation|
+        assert_kind_of ActiveRecord::Relation, relation
+        assert_kind_of Post, relation.first
+      end
+    end
+  end
+
+  def test_in_batches_relations_should_not_overlap_with_each_other
+    seen_posts = []
+    Post.in_batches(of: 2, load: true) do |relation|
+      relation.to_a.each do |post|
+        assert_not seen_posts.include?(post)
+        seen_posts << post
+      end
+    end
+  end
+
+  def test_in_batches_relations_with_condition_should_not_overlap_with_each_other
+    seen_posts = []
+    author_id = Post.first.author_id
+    posts_by_author = Post.where(author_id: author_id)
+    Post.in_batches(of: 2) do |batch|
+      seen_posts += batch.where(author_id: author_id)
+    end
+
+    assert_equal posts_by_author.pluck(:id).sort, seen_posts.map(&:id).sort
+  end
+
+  def test_in_batches_relations_update_all_should_not_affect_matching_records_in_other_batches
+    Post.update_all(author_id: 0)
+    person = Post.last
+    person.update_attributes(author_id: 1)
+
+    Post.in_batches(of: 2) do |batch|
+      batch.where("author_id >= 1").update_all("author_id = author_id + 1")
+    end
+    assert_equal 2, person.reload.author_id # incremented only once
+  end
+
+  def test_find_in_batches_should_return_a_sized_enumerator
+    assert_equal 11, Post.find_in_batches(batch_size: 1).size
+    assert_equal 6, Post.find_in_batches(batch_size: 2).size
+    assert_equal 4, Post.find_in_batches(batch_size: 2, start: 4).size
+    assert_equal 4, Post.find_in_batches(batch_size: 3).size
+    assert_equal 1, Post.find_in_batches(batch_size: 10_000).size
+  end
+
+  [true, false].each do |load|
+    test "in_batches should return limit records when limit is less than batch size and load is #{load}" do
+      limit      = 3
+      batch_size = 5
+      total      = 0
+
+      Post.limit(limit).in_batches(of: batch_size, load: load) do |batch|
+        total += batch.count
+      end
+
+      assert_equal limit, total
+    end
+
+    test "in_batches should return limit records when limit is greater than batch size and load is #{load}" do
+      limit      = 5
+      batch_size = 3
+      total      = 0
+
+      Post.limit(limit).in_batches(of: batch_size, load: load) do |batch|
+        total += batch.count
+      end
+
+      assert_equal limit, total
+    end
+
+    test "in_batches should return limit records when limit is a multiple of the batch size and load is #{load}" do
+      limit      = 6
+      batch_size = 3
+      total      = 0
+
+      Post.limit(limit).in_batches(of: batch_size, load: load) do |batch|
+        total += batch.count
+      end
+
+      assert_equal limit, total
+    end
+
+    test "in_batches should return no records if the limit is 0 and load is #{load}" do
+      limit      = 0
+      batch_size = 1
+      total      = 0
+
+      Post.limit(limit).in_batches(of: batch_size, load: load) do |batch|
+        total += batch.count
+      end
+
+      assert_equal limit, total
+    end
+
+    test "in_batches should return all if the limit is greater than the number of records when load is #{load}" do
+      limit      = @total + 1
+      batch_size = 1
+      total      = 0
+
+      Post.limit(limit).in_batches(of: batch_size, load: load) do |batch|
+        total += batch.count
+      end
+
+      assert_equal @total, total
+    end
+  end
+
+  test ".error_on_ignored_order_or_limit= is deprecated" do
+    begin
+      prev = ActiveRecord::Base.error_on_ignored_order
+      assert_deprecated "Please use error_on_ignored_order= instead." do
+        ActiveRecord::Base.error_on_ignored_order_or_limit = true
+      end
+      assert ActiveRecord::Base.error_on_ignored_order
+    ensure
+      ActiveRecord::Base.error_on_ignored_order = prev
+    end
+  end
+
+  test ".error_on_ignored_order_or_limit is deprecated" do
+    expected = ActiveRecord::Base.error_on_ignored_order
+    actual = assert_deprecated "Please use error_on_ignored_order instead." do
+      ActiveRecord::Base.error_on_ignored_order_or_limit
+    end
+    assert_equal expected, actual
+  end
+
+  test "#error_on_ignored_order_or_limit is deprecated" do
+    expected = ActiveRecord::Base.error_on_ignored_order
+    actual = assert_deprecated "Please use error_on_ignored_order instead." do
+      Post.new.error_on_ignored_order_or_limit
+    end
+    assert_equal expected, actual
+  end
+
+  test ".find_each bypasses the query cache for its own queries" do
+    Post.cache do
+      assert_queries(2) do
+        Post.find_each {}
+        Post.find_each {}
+      end
+    end
+  end
+
+  test ".find_each does not disable the query cache inside the given block" do
+    Post.cache do
+      Post.find_each(start: 1, finish: 1) do |post|
+        assert_queries(1) do
+          post.comments.count
+          post.comments.count
+        end
+      end
+    end
+  end
+
+  test ".find_in_batches bypasses the query cache for its own queries" do
+    Post.cache do
+      assert_queries(2) do
+        Post.find_in_batches {}
+        Post.find_in_batches {}
+      end
+    end
+  end
+
+  test ".find_in_batches does not disable the query cache inside the given block" do
+    Post.cache do
+      Post.find_in_batches(start: 1, finish: 1) do |batch|
+        assert_queries(1) do
+          batch.first.comments.count
+          batch.first.comments.count
+        end
+      end
+    end
+  end
+
+  test ".in_batches bypasses the query cache for its own queries" do
+    Post.cache do
+      assert_queries(2) do
+        Post.in_batches {}
+        Post.in_batches {}
+      end
+    end
+  end
+
+  test ".in_batches does not disable the query cache inside the given block" do
+    Post.cache do
+      Post.in_batches(start: 1, finish: 1) do |relation|
+        assert_queries(1) do
+          relation.count
+          relation.count
+        end
+      end
+    end
+  end
+end