Merge branch 'master' into activestorage-guide

24 files changed, 606 insertions, 674 deletions

diff --git a/activerecord/test/cases/adapters/mysql2/explain_test.rb b/activerecord/test/cases/adapters/mysql2/explain_test.rb
index 2736f7cf0e..b8e778f0b0 100644
--- a/activerecord/test/cases/adapters/mysql2/explain_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/explain_test.rb
@@ -1,23 +1,23 @@
 # frozen_string_literal: true
 
 require "cases/helper"
-require "models/developer"
-require "models/computer"
+require "models/author"
+require "models/post"
 
 class Mysql2ExplainTest < ActiveRecord::Mysql2TestCase
-  fixtures :developers
+  fixtures :authors
 
   def test_explain_for_one_query
-    explain = Developer.where(id: 1).explain
-    assert_match %(EXPLAIN for: SELECT `developers`.* FROM `developers` WHERE `developers`.`id` = 1), explain
-    assert_match %r(developers |.* const), explain
+    explain = Author.where(id: 1).explain
+    assert_match %(EXPLAIN for: SELECT `authors`.* FROM `authors` WHERE `authors`.`id` = 1), explain
+    assert_match %r(authors |.* const), explain
   end
 
   def test_explain_with_eager_loading
-    explain = Developer.where(id: 1).includes(:audit_logs).explain
-    assert_match %(EXPLAIN for: SELECT `developers`.* FROM `developers` WHERE `developers`.`id` = 1), explain
-    assert_match %r(developers |.* const), explain
-    assert_match %(EXPLAIN for: SELECT `audit_logs`.* FROM `audit_logs` WHERE `audit_logs`.`developer_id` = 1), explain
-    assert_match %r(audit_logs |.* ALL), explain
+    explain = Author.where(id: 1).includes(:posts).explain
+    assert_match %(EXPLAIN for: SELECT `authors`.* FROM `authors` WHERE `authors`.`id` = 1), explain
+    assert_match %r(authors |.* const), explain
+    assert_match %(EXPLAIN for: SELECT `posts`.* FROM `posts` WHERE `posts`.`author_id` = 1), explain
+    assert_match %r(posts |.* ALL), explain
   end
 end
diff --git a/activerecord/test/cases/adapters/mysql2/transaction_test.rb b/activerecord/test/cases/adapters/mysql2/transaction_test.rb
index 25d9f69a89..4a3a4503de 100644
--- a/activerecord/test/cases/adapters/mysql2/transaction_test.rb
+++ b/activerecord/test/cases/adapters/mysql2/transaction_test.rb
@@ -60,9 +60,60 @@ module ActiveRecord
       end
     end
 
-    test "raises TransactionTimeout when mysql raises ER_LOCK_WAIT_TIMEOUT" do
+    test "raises TransactionTimeout when lock wait timeout exceeded" do
       assert_raises(ActiveRecord::TransactionTimeout) do
-        ActiveRecord::Base.connection.execute("SIGNAL SQLSTATE 'HY000' SET MESSAGE_TEXT = 'Testing error', MYSQL_ERRNO = 1205;")
+        s = Sample.create!(value: 1)
+        latch1 = Concurrent::CountDownLatch.new
+        latch2 = Concurrent::CountDownLatch.new
+
+        thread = Thread.new do
+          Sample.transaction do
+            Sample.lock.find(s.id)
+            latch1.count_down
+            latch2.wait
+          end
+        end
+
+        begin
+          Sample.transaction do
+            latch1.wait
+            Sample.connection.execute("SET innodb_lock_wait_timeout = 1")
+            Sample.lock.find(s.id)
+          end
+        ensure
+          Sample.connection.execute("SET innodb_lock_wait_timeout = DEFAULT")
+          latch2.count_down
+          thread.join
+        end
+      end
+    end
+
+    test "raises StatementTimeout when statement timeout exceeded" do
+      skip unless ActiveRecord::Base.connection.show_variable("max_execution_time")
+      assert_raises(ActiveRecord::StatementTimeout) do
+        s = Sample.create!(value: 1)
+        latch1 = Concurrent::CountDownLatch.new
+        latch2 = Concurrent::CountDownLatch.new
+
+        thread = Thread.new do
+          Sample.transaction do
+            Sample.lock.find(s.id)
+            latch1.count_down
+            latch2.wait
+          end
+        end
+
+        begin
+          Sample.transaction do
+            latch1.wait
+            Sample.connection.execute("SET max_execution_time = 1")
+            Sample.lock.find(s.id)
+          end
+        ensure
+          Sample.connection.execute("SET max_execution_time = DEFAULT")
+          latch2.count_down
+          thread.join
+        end
       end
     end
   end
diff --git a/activerecord/test/cases/adapters/postgresql/explain_test.rb b/activerecord/test/cases/adapters/postgresql/explain_test.rb
index 16fec94ede..be525383e9 100644
--- a/activerecord/test/cases/adapters/postgresql/explain_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/explain_test.rb
@@ -1,22 +1,22 @@
 # frozen_string_literal: true
 
 require "cases/helper"
-require "models/developer"
-require "models/computer"
+require "models/author"
+require "models/post"
 
 class PostgreSQLExplainTest < ActiveRecord::PostgreSQLTestCase
-  fixtures :developers
+  fixtures :authors
 
   def test_explain_for_one_query
-    explain = Developer.where(id: 1).explain
-    assert_match %r(EXPLAIN for: SELECT "developers"\.\* FROM "developers" WHERE "developers"\."id" = (?:\$1 \[\["id", 1\]\]|1)), explain
+    explain = Author.where(id: 1).explain
+    assert_match %r(EXPLAIN for: SELECT "authors"\.\* FROM "authors" WHERE "authors"\."id" = (?:\$1 \[\["id", 1\]\]|1)), explain
     assert_match %(QUERY PLAN), explain
   end
 
   def test_explain_with_eager_loading
-    explain = Developer.where(id: 1).includes(:audit_logs).explain
+    explain = Author.where(id: 1).includes(:posts).explain
     assert_match %(QUERY PLAN), explain
-    assert_match %r(EXPLAIN for: SELECT "developers"\.\* FROM "developers" WHERE "developers"\."id" = (?:\$1 \[\["id", 1\]\]|1)), explain
-    assert_match %r(EXPLAIN for: SELECT "audit_logs"\.\* FROM "audit_logs" WHERE "audit_logs"\."developer_id" = (?:\$1 \[\["developer_id", 1\]\]|1)), explain
+    assert_match %r(EXPLAIN for: SELECT "authors"\.\* FROM "authors" WHERE "authors"\."id" = (?:\$1 \[\["id", 1\]\]|1)), explain
+    assert_match %r(EXPLAIN for: SELECT "posts"\.\* FROM "posts" WHERE "posts"\."author_id" = (?:\$1 \[\["author_id", 1\]\]|1)), explain
   end
 end
diff --git a/activerecord/test/cases/adapters/postgresql/transaction_test.rb b/activerecord/test/cases/adapters/postgresql/transaction_test.rb
index f56adf4a5e..4d63bbce59 100644
--- a/activerecord/test/cases/adapters/postgresql/transaction_test.rb
+++ b/activerecord/test/cases/adapters/postgresql/transaction_test.rb
@@ -91,6 +91,63 @@ module ActiveRecord
       end
     end
 
+    test "raises TransactionTimeout when lock wait timeout exceeded" do
+      skip unless ActiveRecord::Base.connection.postgresql_version >= 90300
+      assert_raises(ActiveRecord::TransactionTimeout) do
+        s = Sample.create!(value: 1)
+        latch1 = Concurrent::CountDownLatch.new
+        latch2 = Concurrent::CountDownLatch.new
+
+        thread = Thread.new do
+          Sample.transaction do
+            Sample.lock.find(s.id)
+            latch1.count_down
+            latch2.wait
+          end
+        end
+
+        begin
+          Sample.transaction do
+            latch1.wait
+            Sample.connection.execute("SET lock_timeout = 1")
+            Sample.lock.find(s.id)
+          end
+        ensure
+          Sample.connection.execute("SET lock_timeout = DEFAULT")
+          latch2.count_down
+          thread.join
+        end
+      end
+    end
+
+    test "raises StatementTimeout when statement timeout exceeded" do
+      assert_raises(ActiveRecord::StatementTimeout) do
+        s = Sample.create!(value: 1)
+        latch1 = Concurrent::CountDownLatch.new
+        latch2 = Concurrent::CountDownLatch.new
+
+        thread = Thread.new do
+          Sample.transaction do
+            Sample.lock.find(s.id)
+            latch1.count_down
+            latch2.wait
+          end
+        end
+
+        begin
+          Sample.transaction do
+            latch1.wait
+            Sample.connection.execute("SET statement_timeout = 1")
+            Sample.lock.find(s.id)
+          end
+        ensure
+          Sample.connection.execute("SET statement_timeout = DEFAULT")
+          latch2.count_down
+          thread.join
+        end
+      end
+    end
+
     private
 
       def with_warning_suppression
diff --git a/activerecord/test/cases/adapters/sqlite3/explain_test.rb b/activerecord/test/cases/adapters/sqlite3/explain_test.rb
index 3b081d34e1..b6d2ccdb53 100644
--- a/activerecord/test/cases/adapters/sqlite3/explain_test.rb
+++ b/activerecord/test/cases/adapters/sqlite3/explain_test.rb
@@ -1,23 +1,23 @@
 # frozen_string_literal: true
 
 require "cases/helper"
-require "models/developer"
-require "models/computer"
+require "models/author"
+require "models/post"
 
 class SQLite3ExplainTest < ActiveRecord::SQLite3TestCase
-  fixtures :developers
+  fixtures :authors
 
   def test_explain_for_one_query
-    explain = Developer.where(id: 1).explain
-    assert_match %r(EXPLAIN for: SELECT "developers"\.\* FROM "developers" WHERE "developers"\."id" = (?:\? \[\["id", 1\]\]|1)), explain
-    assert_match(/(SEARCH )?TABLE developers USING (INTEGER )?PRIMARY KEY/, explain)
+    explain = Author.where(id: 1).explain
+    assert_match %r(EXPLAIN for: SELECT "authors"\.\* FROM "authors" WHERE "authors"\."id" = (?:\? \[\["id", 1\]\]|1)), explain
+    assert_match(/(SEARCH )?TABLE authors USING (INTEGER )?PRIMARY KEY/, explain)
   end
 
   def test_explain_with_eager_loading
-    explain = Developer.where(id: 1).includes(:audit_logs).explain
-    assert_match %r(EXPLAIN for: SELECT "developers"\.\* FROM "developers" WHERE "developers"\."id" = (?:\? \[\["id", 1\]\]|1)), explain
-    assert_match(/(SEARCH )?TABLE developers USING (INTEGER )?PRIMARY KEY/, explain)
-    assert_match %r(EXPLAIN for: SELECT "audit_logs"\.\* FROM "audit_logs" WHERE "audit_logs"\."developer_id" = (?:\? \[\["developer_id", 1\]\]|1)), explain
-    assert_match(/(SCAN )?TABLE audit_logs/, explain)
+    explain = Author.where(id: 1).includes(:posts).explain
+    assert_match %r(EXPLAIN for: SELECT "authors"\.\* FROM "authors" WHERE "authors"\."id" = (?:\? \[\["id", 1\]\]|1)), explain
+    assert_match(/(SEARCH )?TABLE authors USING (INTEGER )?PRIMARY KEY/, explain)
+    assert_match %r(EXPLAIN for: SELECT "posts"\.\* FROM "posts" WHERE "posts"\."author_id" = (?:\? \[\["author_id", 1\]\]|1)), explain
+    assert_match(/(SCAN )?TABLE posts/, explain)
   end
 end
diff --git a/activerecord/test/cases/associations/cascaded_eager_loading_test.rb b/activerecord/test/cases/associations/cascaded_eager_loading_test.rb
index e69cfe5e52..829e12fbc8 100644
--- a/activerecord/test/cases/associations/cascaded_eager_loading_test.rb
+++ b/activerecord/test/cases/associations/cascaded_eager_loading_test.rb
@@ -37,7 +37,7 @@ class CascadedEagerLoadingTest < ActiveRecord::TestCase
 
   def test_eager_association_loading_with_hmt_does_not_table_name_collide_when_joining_associations
     authors = Author.joins(:posts).eager_load(:comments).where(posts: { tags_count: 1 }).to_a
-    assert_equal 1, assert_no_queries { authors.size }
+    assert_equal 3, assert_no_queries { authors.size }
     assert_equal 10, assert_no_queries { authors[0].comments.size }
   end
 
diff --git a/activerecord/test/cases/associations/eager_test.rb b/activerecord/test/cases/associations/eager_test.rb
index 9afe6a893c..9a042c74db 100644
--- a/activerecord/test/cases/associations/eager_test.rb
+++ b/activerecord/test/cases/associations/eager_test.rb
@@ -427,7 +427,7 @@ class EagerAssociationTest < ActiveRecord::TestCase
   def test_eager_association_loading_with_belongs_to_and_order_string_with_quoted_table_name
     quoted_posts_id = Comment.connection.quote_table_name("posts") + "." + Comment.connection.quote_column_name("id")
     assert_nothing_raised do
-      Comment.includes(:post).references(:posts).order(quoted_posts_id)
+      Comment.includes(:post).references(:posts).order(Arel.sql(quoted_posts_id))
     end
   end
 
@@ -874,14 +874,14 @@ class EagerAssociationTest < ActiveRecord::TestCase
       posts(:thinking, :sti_comments),
       Post.all.merge!(
         includes: [:author, :comments], where: { "authors.name" => "David" },
-        order: "UPPER(posts.title)", limit: 2, offset: 1
+        order: Arel.sql("UPPER(posts.title)"), limit: 2, offset: 1
       ).to_a
     )
     assert_equal(
       posts(:sti_post_and_comments, :sti_comments),
       Post.all.merge!(
         includes: [:author, :comments], where: { "authors.name" => "David" },
-        order: "UPPER(posts.title) DESC", limit: 2, offset: 1
+        order: Arel.sql("UPPER(posts.title) DESC"), limit: 2, offset: 1
       ).to_a
     )
   end
@@ -891,14 +891,14 @@ class EagerAssociationTest < ActiveRecord::TestCase
       posts(:thinking, :sti_comments),
       Post.all.merge!(
         includes: [:author, :comments], where: { "authors.name" => "David" },
-        order: ["UPPER(posts.title)", "posts.id"], limit: 2, offset: 1
+        order: [Arel.sql("UPPER(posts.title)"), "posts.id"], limit: 2, offset: 1
       ).to_a
     )
     assert_equal(
       posts(:sti_post_and_comments, :sti_comments),
       Post.all.merge!(
         includes: [:author, :comments], where: { "authors.name" => "David" },
-        order: ["UPPER(posts.title) DESC", "posts.id"], limit: 2, offset: 1
+        order: [Arel.sql("UPPER(posts.title) DESC"), "posts.id"], limit: 2, offset: 1
       ).to_a
     )
   end
diff --git a/activerecord/test/cases/associations/has_many_associations_test.rb b/activerecord/test/cases/associations/has_many_associations_test.rb
index 6bd11a5d81..4ca11af791 100644
--- a/activerecord/test/cases/associations/has_many_associations_test.rb
+++ b/activerecord/test/cases/associations/has_many_associations_test.rb
@@ -831,7 +831,7 @@ class HasManyAssociationsTest < ActiveRecord::TestCase
   end
 
   def test_find_scoped_grouped_having
-    assert_equal 1, authors(:david).popular_grouped_posts.length
+    assert_equal 2, authors(:david).popular_grouped_posts.length
     assert_equal 0, authors(:mary).popular_grouped_posts.length
   end
 
diff --git a/activerecord/test/cases/attribute_set_test.rb b/activerecord/test/cases/attribute_set_test.rb
deleted file mode 100644
index 8be77ed88f..0000000000
--- a/activerecord/test/cases/attribute_set_test.rb
+++ /dev/null
@@ -1,255 +0,0 @@
-# frozen_string_literal: true
-
-require "cases/helper"
-
-module ActiveRecord
-  class AttributeSetTest < ActiveRecord::TestCase
-    test "building a new set from raw attributes" do
-      builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::Float.new)
-      attributes = builder.build_from_database(foo: "1.1", bar: "2.2")
-
-      assert_equal 1, attributes[:foo].value
-      assert_equal 2.2, attributes[:bar].value
-      assert_equal :foo, attributes[:foo].name
-      assert_equal :bar, attributes[:bar].name
-    end
-
-    test "building with custom types" do
-      builder = AttributeSet::Builder.new(foo: Type::Float.new)
-      attributes = builder.build_from_database({ foo: "3.3", bar: "4.4" }, { bar: Type::Integer.new })
-
-      assert_equal 3.3, attributes[:foo].value
-      assert_equal 4, attributes[:bar].value
-    end
-
-    test "[] returns a null object" do
-      builder = AttributeSet::Builder.new(foo: Type::Float.new)
-      attributes = builder.build_from_database(foo: "3.3")
-
-      assert_equal "3.3", attributes[:foo].value_before_type_cast
-      assert_nil attributes[:bar].value_before_type_cast
-      assert_equal :bar, attributes[:bar].name
-    end
-
-    test "duping creates a new hash, but does not dup the attributes" do
-      builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::String.new)
-      attributes = builder.build_from_database(foo: 1, bar: "foo")
-
-      # Ensure the type cast value is cached
-      attributes[:foo].value
-      attributes[:bar].value
-
-      duped = attributes.dup
-      duped.write_from_database(:foo, 2)
-      duped[:bar].value << "bar"
-
-      assert_equal 1, attributes[:foo].value
-      assert_equal 2, duped[:foo].value
-      assert_equal "foobar", attributes[:bar].value
-      assert_equal "foobar", duped[:bar].value
-    end
-
-    test "deep_duping creates a new hash and dups each attribute" do
-      builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::String.new)
-      attributes = builder.build_from_database(foo: 1, bar: "foo")
-
-      # Ensure the type cast value is cached
-      attributes[:foo].value
-      attributes[:bar].value
-
-      duped = attributes.deep_dup
-      duped.write_from_database(:foo, 2)
-      duped[:bar].value << "bar"
-
-      assert_equal 1, attributes[:foo].value
-      assert_equal 2, duped[:foo].value
-      assert_equal "foo", attributes[:bar].value
-      assert_equal "foobar", duped[:bar].value
-    end
-
-    test "freezing cloned set does not freeze original" do
-      attributes = AttributeSet.new({})
-      clone = attributes.clone
-
-      clone.freeze
-
-      assert clone.frozen?
-      assert_not attributes.frozen?
-    end
-
-    test "to_hash returns a hash of the type cast values" do
-      builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::Float.new)
-      attributes = builder.build_from_database(foo: "1.1", bar: "2.2")
-
-      assert_equal({ foo: 1, bar: 2.2 }, attributes.to_hash)
-      assert_equal({ foo: 1, bar: 2.2 }, attributes.to_h)
-    end
-
-    test "to_hash maintains order" do
-      builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::Float.new)
-      attributes = builder.build_from_database(foo: "2.2", bar: "3.3")
-
-      attributes[:bar]
-      hash = attributes.to_h
-
-      assert_equal [[:foo, 2], [:bar, 3.3]], hash.to_a
-    end
-
-    test "values_before_type_cast" do
-      builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::Integer.new)
-      attributes = builder.build_from_database(foo: "1.1", bar: "2.2")
-
-      assert_equal({ foo: "1.1", bar: "2.2" }, attributes.values_before_type_cast)
-    end
-
-    test "known columns are built with uninitialized attributes" do
-      attributes = attributes_with_uninitialized_key
-      assert attributes[:foo].initialized?
-      assert_not attributes[:bar].initialized?
-    end
-
-    test "uninitialized attributes are not included in the attributes hash" do
-      attributes = attributes_with_uninitialized_key
-      assert_equal({ foo: 1 }, attributes.to_hash)
-    end
-
-    test "uninitialized attributes are not included in keys" do
-      attributes = attributes_with_uninitialized_key
-      assert_equal [:foo], attributes.keys
-    end
-
-    test "uninitialized attributes return false for key?" do
-      attributes = attributes_with_uninitialized_key
-      assert attributes.key?(:foo)
-      assert_not attributes.key?(:bar)
-    end
-
-    test "unknown attributes return false for key?" do
-      attributes = attributes_with_uninitialized_key
-      assert_not attributes.key?(:wibble)
-    end
-
-    test "fetch_value returns the value for the given initialized attribute" do
-      builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::Float.new)
-      attributes = builder.build_from_database(foo: "1.1", bar: "2.2")
-
-      assert_equal 1, attributes.fetch_value(:foo)
-      assert_equal 2.2, attributes.fetch_value(:bar)
-    end
-
-    test "fetch_value returns nil for unknown attributes" do
-      attributes = attributes_with_uninitialized_key
-      assert_nil attributes.fetch_value(:wibble) { "hello" }
-    end
-
-    test "fetch_value returns nil for unknown attributes when types has a default" do
-      types = Hash.new(Type::Value.new)
-      builder = AttributeSet::Builder.new(types)
-      attributes = builder.build_from_database
-
-      assert_nil attributes.fetch_value(:wibble) { "hello" }
-    end
-
-    test "fetch_value uses the given block for uninitialized attributes" do
-      attributes = attributes_with_uninitialized_key
-      value = attributes.fetch_value(:bar) { |n| n.to_s + "!" }
-      assert_equal "bar!", value
-    end
-
-    test "fetch_value returns nil for uninitialized attributes if no block is given" do
-      attributes = attributes_with_uninitialized_key
-      assert_nil attributes.fetch_value(:bar)
-    end
-
-    test "the primary_key is always initialized" do
-      builder = AttributeSet::Builder.new({ foo: Type::Integer.new }, :foo)
-      attributes = builder.build_from_database
-
-      assert attributes.key?(:foo)
-      assert_equal [:foo], attributes.keys
-      assert attributes[:foo].initialized?
-    end
-
-    class MyType
-      def cast(value)
-        return if value.nil?
-        value + " from user"
-      end
-
-      def deserialize(value)
-        return if value.nil?
-        value + " from database"
-      end
-
-      def assert_valid_value(*)
-      end
-    end
-
-    test "write_from_database sets the attribute with database typecasting" do
-      builder = AttributeSet::Builder.new(foo: MyType.new)
-      attributes = builder.build_from_database
-
-      assert_nil attributes.fetch_value(:foo)
-
-      attributes.write_from_database(:foo, "value")
-
-      assert_equal "value from database", attributes.fetch_value(:foo)
-    end
-
-    test "write_from_user sets the attribute with user typecasting" do
-      builder = AttributeSet::Builder.new(foo: MyType.new)
-      attributes = builder.build_from_database
-
-      assert_nil attributes.fetch_value(:foo)
-
-      attributes.write_from_user(:foo, "value")
-
-      assert_equal "value from user", attributes.fetch_value(:foo)
-    end
-
-    def attributes_with_uninitialized_key
-      builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::Float.new)
-      builder.build_from_database(foo: "1.1")
-    end
-
-    test "freezing doesn't prevent the set from materializing" do
-      builder = AttributeSet::Builder.new(foo: Type::String.new)
-      attributes = builder.build_from_database(foo: "1")
-
-      attributes.freeze
-      assert_equal({ foo: "1" }, attributes.to_hash)
-    end
-
-    test "#accessed_attributes returns only attributes which have been read" do
-      builder = AttributeSet::Builder.new(foo: Type::Value.new, bar: Type::Value.new)
-      attributes = builder.build_from_database(foo: "1", bar: "2")
-
-      assert_equal [], attributes.accessed
-
-      attributes.fetch_value(:foo)
-
-      assert_equal [:foo], attributes.accessed
-    end
-
-    test "#map returns a new attribute set with the changes applied" do
-      builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::Integer.new)
-      attributes = builder.build_from_database(foo: "1", bar: "2")
-      new_attributes = attributes.map do |attr|
-        attr.with_cast_value(attr.value + 1)
-      end
-
-      assert_equal 2, new_attributes.fetch_value(:foo)
-      assert_equal 3, new_attributes.fetch_value(:bar)
-    end
-
-    test "comparison for equality is correctly implemented" do
-      builder = AttributeSet::Builder.new(foo: Type::Integer.new, bar: Type::Integer.new)
-      attributes = builder.build_from_database(foo: "1", bar: "2")
-      attributes2 = builder.build_from_database(foo: "1", bar: "2")
-      attributes3 = builder.build_from_database(foo: "2", bar: "2")
-
-      assert_equal attributes, attributes2
-      assert_not_equal attributes2, attributes3
-    end
-  end
-end
diff --git a/activerecord/test/cases/attribute_test.rb b/activerecord/test/cases/attribute_test.rb
deleted file mode 100644
index 1731e7926e..0000000000
--- a/activerecord/test/cases/attribute_test.rb
+++ /dev/null
@@ -1,255 +0,0 @@
-# frozen_string_literal: true
-
-require "cases/helper"
-
-module ActiveRecord
-  class AttributeTest < ActiveRecord::TestCase
-    setup do
-      @type = Minitest::Mock.new
-    end
-
-    teardown do
-      assert @type.verify
-    end
-
-    test "from_database + read type casts from database" do
-      @type.expect(:deserialize, "type cast from database", ["a value"])
-      attribute = Attribute.from_database(nil, "a value", @type)
-
-      type_cast_value = attribute.value
-
-      assert_equal "type cast from database", type_cast_value
-    end
-
-    test "from_user + read type casts from user" do
-      @type.expect(:cast, "type cast from user", ["a value"])
-      attribute = Attribute.from_user(nil, "a value", @type)
-
-      type_cast_value = attribute.value
-
-      assert_equal "type cast from user", type_cast_value
-    end
-
-    test "reading memoizes the value" do
-      @type.expect(:deserialize, "from the database", ["whatever"])
-      attribute = Attribute.from_database(nil, "whatever", @type)
-
-      type_cast_value = attribute.value
-      second_read = attribute.value
-
-      assert_equal "from the database", type_cast_value
-      assert_same type_cast_value, second_read
-    end
-
-    test "reading memoizes falsy values" do
-      @type.expect(:deserialize, false, ["whatever"])
-      attribute = Attribute.from_database(nil, "whatever", @type)
-
-      attribute.value
-      attribute.value
-    end
-
-    test "read_before_typecast returns the given value" do
-      attribute = Attribute.from_database(nil, "raw value", @type)
-
-      raw_value = attribute.value_before_type_cast
-
-      assert_equal "raw value", raw_value
-    end
-
-    test "from_database + read_for_database type casts to and from database" do
-      @type.expect(:deserialize, "read from database", ["whatever"])
-      @type.expect(:serialize, "ready for database", ["read from database"])
-      attribute = Attribute.from_database(nil, "whatever", @type)
-
-      serialize = attribute.value_for_database
-
-      assert_equal "ready for database", serialize
-    end
-
-    test "from_user + read_for_database type casts from the user to the database" do
-      @type.expect(:cast, "read from user", ["whatever"])
-      @type.expect(:serialize, "ready for database", ["read from user"])
-      attribute = Attribute.from_user(nil, "whatever", @type)
-
-      serialize = attribute.value_for_database
-
-      assert_equal "ready for database", serialize
-    end
-
-    test "duping dups the value" do
-      @type.expect(:deserialize, "type cast".dup, ["a value"])
-      attribute = Attribute.from_database(nil, "a value", @type)
-
-      value_from_orig = attribute.value
-      value_from_clone = attribute.dup.value
-      value_from_orig << " foo"
-
-      assert_equal "type cast foo", value_from_orig
-      assert_equal "type cast", value_from_clone
-    end
-
-    test "duping does not dup the value if it is not dupable" do
-      @type.expect(:deserialize, false, ["a value"])
-      attribute = Attribute.from_database(nil, "a value", @type)
-
-      assert_same attribute.value, attribute.dup.value
-    end
-
-    test "duping does not eagerly type cast if we have not yet type cast" do
-      attribute = Attribute.from_database(nil, "a value", @type)
-      attribute.dup
-    end
-
-    class MyType
-      def cast(value)
-        value + " from user"
-      end
-
-      def deserialize(value)
-        value + " from database"
-      end
-
-      def assert_valid_value(*)
-      end
-    end
-
-    test "with_value_from_user returns a new attribute with the value from the user" do
-      old = Attribute.from_database(nil, "old", MyType.new)
-      new = old.with_value_from_user("new")
-
-      assert_equal "old from database", old.value
-      assert_equal "new from user", new.value
-    end
-
-    test "with_value_from_database returns a new attribute with the value from the database" do
-      old = Attribute.from_user(nil, "old", MyType.new)
-      new = old.with_value_from_database("new")
-
-      assert_equal "old from user", old.value
-      assert_equal "new from database", new.value
-    end
-
-    test "uninitialized attributes yield their name if a block is given to value" do
-      block = proc { |name| name.to_s + "!" }
-      foo = Attribute.uninitialized(:foo, nil)
-      bar = Attribute.uninitialized(:bar, nil)
-
-      assert_equal "foo!", foo.value(&block)
-      assert_equal "bar!", bar.value(&block)
-    end
-
-    test "uninitialized attributes have no value" do
-      assert_nil Attribute.uninitialized(:foo, nil).value
-    end
-
-    test "attributes equal other attributes with the same constructor arguments" do
-      first = Attribute.from_database(:foo, 1, Type::Integer.new)
-      second = Attribute.from_database(:foo, 1, Type::Integer.new)
-      assert_equal first, second
-    end
-
-    test "attributes do not equal attributes with different names" do
-      first = Attribute.from_database(:foo, 1, Type::Integer.new)
-      second = Attribute.from_database(:bar, 1, Type::Integer.new)
-      assert_not_equal first, second
-    end
-
-    test "attributes do not equal attributes with different types" do
-      first = Attribute.from_database(:foo, 1, Type::Integer.new)
-      second = Attribute.from_database(:foo, 1, Type::Float.new)
-      assert_not_equal first, second
-    end
-
-    test "attributes do not equal attributes with different values" do
-      first = Attribute.from_database(:foo, 1, Type::Integer.new)
-      second = Attribute.from_database(:foo, 2, Type::Integer.new)
-      assert_not_equal first, second
-    end
-
-    test "attributes do not equal attributes of other classes" do
-      first = Attribute.from_database(:foo, 1, Type::Integer.new)
-      second = Attribute.from_user(:foo, 1, Type::Integer.new)
-      assert_not_equal first, second
-    end
-
-    test "an attribute has not been read by default" do
-      attribute = Attribute.from_database(:foo, 1, Type::Value.new)
-      assert_not attribute.has_been_read?
-    end
-
-    test "an attribute has been read when its value is calculated" do
-      attribute = Attribute.from_database(:foo, 1, Type::Value.new)
-      attribute.value
-      assert attribute.has_been_read?
-    end
-
-    test "an attribute is not changed if it hasn't been assigned or mutated" do
-      attribute = Attribute.from_database(:foo, 1, Type::Value.new)
-
-      refute attribute.changed?
-    end
-
-    test "an attribute is changed if it's been assigned a new value" do
-      attribute = Attribute.from_database(:foo, 1, Type::Value.new)
-      changed = attribute.with_value_from_user(2)
-
-      assert changed.changed?
-    end
-
-    test "an attribute is not changed if it's assigned the same value" do
-      attribute = Attribute.from_database(:foo, 1, Type::Value.new)
-      unchanged = attribute.with_value_from_user(1)
-
-      refute unchanged.changed?
-    end
-
-    test "an attribute can not be mutated if it has not been read,
-      and skips expensive calculations" do
-      type_which_raises_from_all_methods = Object.new
-      attribute = Attribute.from_database(:foo, "bar", type_which_raises_from_all_methods)
-
-      assert_not attribute.changed_in_place?
-    end
-
-    test "an attribute is changed if it has been mutated" do
-      attribute = Attribute.from_database(:foo, "bar", Type::String.new)
-      attribute.value << "!"
-
-      assert attribute.changed_in_place?
-      assert attribute.changed?
-    end
-
-    test "an attribute can forget its changes" do
-      attribute = Attribute.from_database(:foo, "bar", Type::String.new)
-      changed = attribute.with_value_from_user("foo")
-      forgotten = changed.forgetting_assignment
-
-      assert changed.changed? # sanity check
-      refute forgotten.changed?
-    end
-
-    test "with_value_from_user validates the value" do
-      type = Type::Value.new
-      type.define_singleton_method(:assert_valid_value) do |value|
-        if value == 1
-          raise ArgumentError
-        end
-      end
-
-      attribute = Attribute.from_database(:foo, 1, type)
-      assert_equal 1, attribute.value
-      assert_equal 2, attribute.with_value_from_user(2).value
-      assert_raises ArgumentError do
-        attribute.with_value_from_user(1)
-      end
-    end
-
-    test "with_type preserves mutations" do
-      attribute = Attribute.from_database(:foo, "".dup, Type::Value.new)
-      attribute.value << "1"
-
-      assert_equal 1, attribute.with_type(Type::Integer.new).value
-    end
-  end
-end
diff --git a/activerecord/test/cases/base_test.rb b/activerecord/test/cases/base_test.rb
index f0ef522515..d79afa2ee9 100644
--- a/activerecord/test/cases/base_test.rb
+++ b/activerecord/test/cases/base_test.rb
@@ -1476,4 +1476,25 @@ class BasicsTest < ActiveRecord::TestCase
     assert_equal(%w(first_name last_name), Developer.ignored_columns)
     assert_equal(%w(first_name last_name), SymbolIgnoredDeveloper.ignored_columns)
   end
+
+  test "when #reload called, ignored columns' attribute methods are not defined" do
+    developer = Developer.create!(name: "Developer")
+    refute developer.respond_to?(:first_name)
+    refute developer.respond_to?(:first_name=)
+
+    developer.reload
+
+    refute developer.respond_to?(:first_name)
+    refute developer.respond_to?(:first_name=)
+  end
+
+  test "ignored columns not included in SELECT" do
+    query = Developer.all.to_sql.downcase
+
+    # ignored column
+    refute query.include?("first_name")
+
+    # regular column
+    assert query.include?("name")
+  end
 end
diff --git a/activerecord/test/cases/calculations_test.rb b/activerecord/test/cases/calculations_test.rb
index 66bc14b5ab..55b50e4f84 100644
--- a/activerecord/test/cases/calculations_test.rb
+++ b/activerecord/test/cases/calculations_test.rb
@@ -663,14 +663,14 @@ class CalculationsTest < ActiveRecord::TestCase
   end
 
   def test_pluck_with_selection_clause
-    assert_equal [50, 53, 55, 60], Account.pluck("DISTINCT credit_limit").sort
-    assert_equal [50, 53, 55, 60], Account.pluck("DISTINCT accounts.credit_limit").sort
-    assert_equal [50, 53, 55, 60], Account.pluck("DISTINCT(credit_limit)").sort
+    assert_equal [50, 53, 55, 60], Account.pluck(Arel.sql("DISTINCT credit_limit")).sort
+    assert_equal [50, 53, 55, 60], Account.pluck(Arel.sql("DISTINCT accounts.credit_limit")).sort
+    assert_equal [50, 53, 55, 60], Account.pluck(Arel.sql("DISTINCT(credit_limit)")).sort
 
     # MySQL returns "SUM(DISTINCT(credit_limit))" as the column name unless
     # an alias is provided.  Without the alias, the column cannot be found
     # and properly typecast.
-    assert_equal [50 + 53 + 55 + 60], Account.pluck("SUM(DISTINCT(credit_limit)) as credit_limit")
+    assert_equal [50 + 53 + 55 + 60], Account.pluck(Arel.sql("SUM(DISTINCT(credit_limit)) as credit_limit"))
   end
 
   def test_plucks_with_ids
@@ -772,7 +772,7 @@ class CalculationsTest < ActiveRecord::TestCase
     companies = Company.order(:name).limit(3).load
 
     assert_queries 1 do
-      assert_equal ["37signals", "Apex", "Ex Nihilo"], companies.pluck("DISTINCT name")
+      assert_equal ["37signals", "Apex", "Ex Nihilo"], companies.pluck(Arel.sql("DISTINCT name"))
     end
   end
 
diff --git a/activerecord/test/cases/connection_pool_test.rb b/activerecord/test/cases/connection_pool_test.rb
index 2bfe490602..cb2fefb4f6 100644
--- a/activerecord/test/cases/connection_pool_test.rb
+++ b/activerecord/test/cases/connection_pool_test.rb
@@ -205,6 +205,14 @@ module ActiveRecord
         end.join
       end
 
+      def test_checkout_order_is_lifo
+        conn1 = @pool.checkout
+        conn2 = @pool.checkout
+        @pool.checkin conn1
+        @pool.checkin conn2
+        assert_equal [conn2, conn1], 2.times.map { @pool.checkout }
+      end
+
       # The connection pool is "fair" if threads waiting for
       # connections receive them in the order in which they began
       # waiting.  This ensures that we don't timeout one HTTP request
diff --git a/activerecord/test/cases/finder_test.rb b/activerecord/test/cases/finder_test.rb
index d8bc917e7f..1268949ba9 100644
--- a/activerecord/test/cases/finder_test.rb
+++ b/activerecord/test/cases/finder_test.rb
@@ -239,7 +239,7 @@ class FinderTest < ActiveRecord::TestCase
 
   # Ensure +exists?+ runs without an error by excluding order value.
   def test_exists_with_order
-    assert_equal true, Topic.order("invalid sql here").exists?
+    assert_equal true, Topic.order(Arel.sql("invalid sql here")).exists?
   end
 
   def test_exists_with_joins
@@ -652,7 +652,7 @@ class FinderTest < ActiveRecord::TestCase
 
   def test_last_with_irreversible_order
     assert_raises(ActiveRecord::IrreversibleOrderError) do
-      Topic.order("coalesce(author_name, title)").last
+      Topic.order(Arel.sql("coalesce(author_name, title)")).last
     end
   end
 
diff --git a/activerecord/test/cases/invertible_migration_test.rb b/activerecord/test/cases/invertible_migration_test.rb
index 60c628511f..ebe0b0aa87 100644
--- a/activerecord/test/cases/invertible_migration_test.rb
+++ b/activerecord/test/cases/invertible_migration_test.rb
@@ -161,6 +161,15 @@ module ActiveRecord
       end
     end
 
+    class UpOnlyMigration < SilentMigration
+      def change
+        add_column :horses, :oldie, :integer, default: 0
+        up_only { execute "update horses set oldie = 1" }
+      end
+    end
+
+    self.use_transactional_tests = false
+
     setup do
       @verbose_was, ActiveRecord::Migration.verbose = ActiveRecord::Migration.verbose, false
     end
@@ -378,5 +387,23 @@ module ActiveRecord
               "horses_index_named index should not exist"
       end
     end
+
+    def test_up_only
+      InvertibleMigration.new.migrate(:up)
+      horse1 = Horse.create
+      # populates existing horses with oldie = 1 but new ones have default 0
+      UpOnlyMigration.new.migrate(:up)
+      Horse.reset_column_information
+      horse1.reload
+      horse2 = Horse.create
+
+      assert 1, horse1.oldie # created before migration
+      assert 0, horse2.oldie # created after migration
+
+      UpOnlyMigration.new.migrate(:down) # should be no error
+      connection = ActiveRecord::Base.connection
+      assert !connection.column_exists?(:horses, :oldie)
+      Horse.reset_column_information
+    end
   end
 end
diff --git a/activerecord/test/cases/query_cache_test.rb b/activerecord/test/cases/query_cache_test.rb
index 5cb537b623..46f90b0bca 100644
--- a/activerecord/test/cases/query_cache_test.rb
+++ b/activerecord/test/cases/query_cache_test.rb
@@ -452,6 +452,15 @@ class QueryCacheTest < ActiveRecord::TestCase
     end
   end
 
+  def test_query_cache_is_enabled_on_all_connection_pools
+    middleware {
+      ActiveRecord::Base.connection_handler.connection_pool_list.each do |pool|
+        assert pool.query_cache_enabled
+        assert pool.connection.query_cache_enabled
+      end
+    }.call({})
+  end
+
   private
     def middleware(&app)
       executor = Class.new(ActiveSupport::Executor)
diff --git a/activerecord/test/cases/relation_test.rb b/activerecord/test/cases/relation_test.rb
index fd5985ffe7..a71d8de521 100644
--- a/activerecord/test/cases/relation_test.rb
+++ b/activerecord/test/cases/relation_test.rb
@@ -274,18 +274,32 @@ module ActiveRecord
       assert_equal({ 2 => 1, 4 => 3, 5 => 1 }, authors(:david).posts.merge(posts_with_special_comments_with_ratings).count)
     end
 
+    def test_relation_merging_keeps_joining_order
+      authors  = Author.where(id: 1)
+      posts    = Post.joins(:author).merge(authors)
+      comments = Comment.joins(:post).merge(posts)
+      ratings  = Rating.joins(:comment).merge(comments)
+
+      assert_equal 3, ratings.count
+    end
+
     class EnsureRoundTripTypeCasting < ActiveRecord::Type::Value
       def type
         :string
       end
 
+      def cast(value)
+        raise value unless value == "value from user"
+        "cast value"
+      end
+
       def deserialize(value)
         raise value unless value == "type cast for database"
         "type cast from database"
       end
 
       def serialize(value)
-        raise value unless value == "value from user"
+        raise value unless value == "cast value"
         "type cast for database"
       end
     end
diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index 72433d1e8e..50ad1d5b26 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -195,6 +195,18 @@ class RelationTest < ActiveRecord::TestCase
     assert_equal(relation.map(&:post_count).sort, subquery.values.sort)
   end
 
+  def test_finding_with_subquery_with_eager_loading_in_from
+    relation = Comment.includes(:post).where("posts.type": "Post")
+    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_with_eager_loading_in_where
+    relation = Comment.includes(:post).where("posts.type": "Post")
+    assert_equal relation.sort_by(&:id), Comment.where(id: relation).sort_by(&:id)
+  end
+
   def test_finding_with_conditions
     assert_equal ["David"], Author.where(name: "David").map(&:name)
     assert_equal ["Mary"],  Author.where(["name = ?", "Mary"]).map(&:name)
@@ -238,7 +250,7 @@ class RelationTest < ActiveRecord::TestCase
   end
 
   def test_reverse_order_with_function
-    topics = Topic.order("length(title)").reverse_order
+    topics = Topic.order(Arel.sql("length(title)")).reverse_order
     assert_equal topics(:second).title, topics.first.title
   end
 
@@ -248,24 +260,24 @@ class RelationTest < ActiveRecord::TestCase
   end
 
   def test_reverse_order_with_function_other_predicates
-    topics = Topic.order("author_name, length(title), id").reverse_order
+    topics = Topic.order(Arel.sql("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
+    topics = Topic.order(Arel.sql("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
+      Topic.order(Arel.sql("concat(author_name, title)")).reverse_order
     end
     assert_raises(ActiveRecord::IrreversibleOrderError) do
-      Topic.order("concat(lower(author_name), title)").reverse_order
+      Topic.order(Arel.sql("concat(lower(author_name), title)")).reverse_order
     end
     assert_raises(ActiveRecord::IrreversibleOrderError) do
-      Topic.order("concat(author_name, lower(title))").reverse_order
+      Topic.order(Arel.sql("concat(author_name, lower(title))")).reverse_order
     end
     assert_raises(ActiveRecord::IrreversibleOrderError) do
-      Topic.order("concat(lower(author_name), title, length(title)").reverse_order
+      Topic.order(Arel.sql("concat(lower(author_name), title, length(title)")).reverse_order
     end
   end
 
@@ -277,10 +289,10 @@ class RelationTest < ActiveRecord::TestCase
 
   def test_reverse_order_with_nulls_first_or_last
     assert_raises(ActiveRecord::IrreversibleOrderError) do
-      Topic.order("title NULLS FIRST").reverse_order
+      Topic.order(Arel.sql("title NULLS FIRST")).reverse_order
     end
     assert_raises(ActiveRecord::IrreversibleOrderError) do
-      Topic.order("title nulls last").reverse_order
+      Topic.order(Arel.sql("title nulls last")).reverse_order
     end
   end
 
@@ -373,29 +385,29 @@ class RelationTest < ActiveRecord::TestCase
 
   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)").
+              order("tags.name asc", "taggings.taggable_id asc", Arel.sql("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
+    tags = Tag.includes(:taggings).references(:taggings).order(Arel.sql("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
+    tags = Tag.includes(:taggings).references(:taggings).order(Arel.sql("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
+    query = Tag.order([Arel.sql("field(id, ?)"), [1, 3, 2]]).to_sql
     assert_match(/field\(id, 1,3,2\)/, query)
 
-    query = Tag.order(["field(id, ?)", []]).to_sql
+    query = Tag.order([Arel.sql("field(id, ?)"), []]).to_sql
     assert_match(/field\(id, NULL\)/, query)
 
-    query = Tag.order(["field(id, ?)", nil]).to_sql
+    query = Tag.order([Arel.sql("field(id, ?)"), nil]).to_sql
     assert_match(/field\(id, NULL\)/, query)
   end
 
@@ -927,13 +939,13 @@ class RelationTest < ActiveRecord::TestCase
     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
+    assert_equal 3, posts.where("comments_count > 1").count
+    assert_equal 6, 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? }
+    assert_equal 8, posts.count { |p| p.comments_count.even? }
   end
 
   def test_count_on_association_relation
@@ -950,10 +962,10 @@ class RelationTest < ActiveRecord::TestCase
   def test_count_with_distinct
     posts = Post.all
 
-    assert_equal 3, posts.distinct(true).count(:comments_count)
+    assert_equal 4, 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 4, posts.distinct(true).select(:comments_count).count
     assert_equal 11, posts.distinct(false).select(:comments_count).count
   end
 
@@ -992,7 +1004,7 @@ class RelationTest < ActiveRecord::TestCase
 
     best_posts = posts.where(comments_count: 0)
     best_posts.load # force load
-    assert_no_queries { assert_equal 9, best_posts.size }
+    assert_no_queries { assert_equal 6, best_posts.size }
   end
 
   def test_size_with_limit
@@ -1003,7 +1015,7 @@ class RelationTest < ActiveRecord::TestCase
 
     best_posts = posts.where(comments_count: 0)
     best_posts.load # force load
-    assert_no_queries { assert_equal 9, best_posts.size }
+    assert_no_queries { assert_equal 6, best_posts.size }
   end
 
   def test_size_with_zero_limit
@@ -1026,7 +1038,7 @@ class RelationTest < ActiveRecord::TestCase
   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 }
+    expected = { 1 => 4, 2 => 1 }
     assert_equal expected, posts.count
   end
 
@@ -1567,7 +1579,7 @@ class RelationTest < ActiveRecord::TestCase
     scope = Post.order("comments.body")
     assert_equal ["comments"], scope.references_values
 
-    scope = Post.order("#{Comment.quoted_table_name}.#{Comment.quoted_primary_key}")
+    scope = Post.order(Arel.sql("#{Comment.quoted_table_name}.#{Comment.quoted_primary_key}"))
     if current_adapter?(:OracleAdapter)
       assert_equal ["COMMENTS"], scope.references_values
     else
@@ -1584,7 +1596,7 @@ class RelationTest < ActiveRecord::TestCase
     scope = Post.order("comments.body asc")
     assert_equal ["comments"], scope.references_values
 
-    scope = Post.order("foo(comments.body)")
+    scope = Post.order(Arel.sql("foo(comments.body)"))
     assert_equal [], scope.references_values
   end
 
@@ -1592,7 +1604,7 @@ class RelationTest < ActiveRecord::TestCase
     scope = Post.reorder("comments.body")
     assert_equal %w(comments), scope.references_values
 
-    scope = Post.reorder("#{Comment.quoted_table_name}.#{Comment.quoted_primary_key}")
+    scope = Post.reorder(Arel.sql("#{Comment.quoted_table_name}.#{Comment.quoted_primary_key}"))
     if current_adapter?(:OracleAdapter)
       assert_equal ["COMMENTS"], scope.references_values
     else
@@ -1609,7 +1621,7 @@ class RelationTest < ActiveRecord::TestCase
     scope = Post.reorder("comments.body asc")
     assert_equal %w(comments), scope.references_values
 
-    scope = Post.reorder("foo(comments.body)")
+    scope = Post.reorder(Arel.sql("foo(comments.body)"))
     assert_equal [], scope.references_values
   end
 
@@ -1781,7 +1793,7 @@ class RelationTest < ActiveRecord::TestCase
   end
 
   test "arel_attribute respects a custom table" do
-    assert_equal [posts(:welcome)], custom_post_relation.ranked_by_comments.limit_by(1).to_a
+    assert_equal [posts(:sti_comments)], custom_post_relation.ranked_by_comments.limit_by(1).to_a
   end
 
   test "alias_tracker respects a custom table" do
diff --git a/activerecord/test/cases/scoping/default_scoping_test.rb b/activerecord/test/cases/scoping/default_scoping_test.rb
index 716ca29eda..fdfeabaa3b 100644
--- a/activerecord/test/cases/scoping/default_scoping_test.rb
+++ b/activerecord/test/cases/scoping/default_scoping_test.rb
@@ -120,49 +120,49 @@ class DefaultScopingTest < ActiveRecord::TestCase
   def test_unscope_with_where_attributes
     expected = Developer.order("salary DESC").collect(&:name)
     received = DeveloperOrderedBySalary.where(name: "David").unscope(where: :name).collect(&:name)
-    assert_equal expected, received
+    assert_equal expected.sort, received.sort
 
     expected_2 = Developer.order("salary DESC").collect(&:name)
     received_2 = DeveloperOrderedBySalary.select("id").where("name" => "Jamis").unscope({ where: :name }, :select).collect(&:name)
-    assert_equal expected_2, received_2
+    assert_equal expected_2.sort, received_2.sort
 
     expected_3 = Developer.order("salary DESC").collect(&:name)
     received_3 = DeveloperOrderedBySalary.select("id").where("name" => "Jamis").unscope(:select, :where).collect(&:name)
-    assert_equal expected_3, received_3
+    assert_equal expected_3.sort, received_3.sort
 
     expected_4 = Developer.order("salary DESC").collect(&:name)
     received_4 = DeveloperOrderedBySalary.where.not("name" => "Jamis").unscope(where: :name).collect(&:name)
-    assert_equal expected_4, received_4
+    assert_equal expected_4.sort, received_4.sort
 
     expected_5 = Developer.order("salary DESC").collect(&:name)
     received_5 = DeveloperOrderedBySalary.where.not("name" => ["Jamis", "David"]).unscope(where: :name).collect(&:name)
-    assert_equal expected_5, received_5
+    assert_equal expected_5.sort, received_5.sort
 
     expected_6 = Developer.order("salary DESC").collect(&:name)
     received_6 = DeveloperOrderedBySalary.where(Developer.arel_table["name"].eq("David")).unscope(where: :name).collect(&:name)
-    assert_equal expected_6, received_6
+    assert_equal expected_6.sort, received_6.sort
 
     expected_7 = Developer.order("salary DESC").collect(&:name)
     received_7 = DeveloperOrderedBySalary.where(Developer.arel_table[:name].eq("David")).unscope(where: :name).collect(&:name)
-    assert_equal expected_7, received_7
+    assert_equal expected_7.sort, received_7.sort
   end
 
   def test_unscope_comparison_where_clauses
     # unscoped for WHERE (`developers`.`id` <= 2)
     expected = Developer.order("salary DESC").collect(&:name)
     received = DeveloperOrderedBySalary.where(id: -Float::INFINITY..2).unscope(where: :id).collect { |dev| dev.name }
-    assert_equal expected, received
+    assert_equal expected.sort, received.sort
 
     # unscoped for WHERE (`developers`.`id` < 2)
     expected = Developer.order("salary DESC").collect(&:name)
     received = DeveloperOrderedBySalary.where(id: -Float::INFINITY...2).unscope(where: :id).collect { |dev| dev.name }
-    assert_equal expected, received
+    assert_equal expected.sort, received.sort
   end
 
   def test_unscope_multiple_where_clauses
     expected = Developer.order("salary DESC").collect(&:name)
     received = DeveloperOrderedBySalary.where(name: "Jamis").where(id: 1).unscope(where: [:name, :id]).collect(&:name)
-    assert_equal expected, received
+    assert_equal expected.sort, received.sort
   end
 
   def test_unscope_string_where_clauses_involved
@@ -172,23 +172,23 @@ class DefaultScopingTest < ActiveRecord::TestCase
     dev_ordered_relation = DeveloperOrderedBySalary.where(name: "Jamis").where("created_at > ?", 1.year.ago)
     received = dev_ordered_relation.unscope(where: [:name]).collect(&:name)
 
-    assert_equal expected, received
+    assert_equal expected.sort, received.sort
   end
 
   def test_unscope_with_grouping_attributes
     expected = Developer.order("salary DESC").collect(&:name)
     received = DeveloperOrderedBySalary.group(:name).unscope(:group).collect(&:name)
-    assert_equal expected, received
+    assert_equal expected.sort, received.sort
 
     expected_2 = Developer.order("salary DESC").collect(&:name)
     received_2 = DeveloperOrderedBySalary.group("name").unscope(:group).collect(&:name)
-    assert_equal expected_2, received_2
+    assert_equal expected_2.sort, received_2.sort
   end
 
   def test_unscope_with_limit_in_query
     expected = Developer.order("salary DESC").collect(&:name)
     received = DeveloperOrderedBySalary.limit(1).unscope(:limit).collect(&:name)
-    assert_equal expected, received
+    assert_equal expected.sort, received.sort
   end
 
   def test_order_to_unscope_reordering
@@ -472,7 +472,7 @@ class DefaultScopingTest < ActiveRecord::TestCase
   test "a scope can remove the condition from the default scope" do
     scope = DeveloperCalledJamis.david2
     assert_equal 1, scope.where_clause.ast.children.length
-    assert_equal Developer.where(name: "David"), scope
+    assert_equal Developer.where(name: "David").map(&:id), scope.map(&:id)
   end
 
   def test_with_abstract_class_where_clause_should_not_be_duplicated
diff --git a/activerecord/test/cases/tasks/mysql_rake_test.rb b/activerecord/test/cases/tasks/mysql_rake_test.rb
index 98fe24baa0..047153e7cc 100644
--- a/activerecord/test/cases/tasks/mysql_rake_test.rb
+++ b/activerecord/test/cases/tasks/mysql_rake_test.rb
@@ -75,7 +75,7 @@ if current_adapter?(:Mysql2Adapter)
       end
     end
 
-    class MysqlDBCreateAsRootTest < ActiveRecord::TestCase
+    class MysqlDBCreateWithInvalidPermissionsTest < ActiveRecord::TestCase
       def setup
         @connection    = stub("Connection", create_database: true)
         @error         = Mysql2::Error.new("Invalid permissions")
@@ -86,13 +86,8 @@ if current_adapter?(:Mysql2Adapter)
           "password" => "wossname"
         }
 
-        $stdin.stubs(:gets).returns("secret\n")
-        $stdout.stubs(:print).returns(nil)
-        @error.stubs(:errno).returns(1045)
         ActiveRecord::Base.stubs(:connection).returns(@connection)
-        ActiveRecord::Base.stubs(:establish_connection).
-          raises(@error).
-          then.returns(true)
+        ActiveRecord::Base.stubs(:establish_connection).raises(@error)
 
         $stdout, @original_stdout = StringIO.new, $stdout
         $stderr, @original_stderr = StringIO.new, $stderr
@@ -102,75 +97,11 @@ if current_adapter?(:Mysql2Adapter)
         $stdout, $stderr = @original_stdout, @original_stderr
       end
 
-      def test_root_password_is_requested
-        assert_permissions_granted_for("pat")
-        $stdin.expects(:gets).returns("secret\n")
-
-        ActiveRecord::Tasks::DatabaseTasks.create @configuration
-      end
-
-      def test_connection_established_as_root
-        assert_permissions_granted_for("pat")
-        ActiveRecord::Base.expects(:establish_connection).with(
-          "adapter"  => "mysql2",
-          "database" => nil,
-          "username" => "root",
-          "password" => "secret"
-        )
-
-        ActiveRecord::Tasks::DatabaseTasks.create @configuration
-      end
-
-      def test_database_created_by_root
-        assert_permissions_granted_for("pat")
-        @connection.expects(:create_database).
-          with("my-app-db", {})
-
-        ActiveRecord::Tasks::DatabaseTasks.create @configuration
-      end
-
-      def test_grant_privileges_for_normal_user
-        assert_permissions_granted_for("pat")
-        ActiveRecord::Tasks::DatabaseTasks.create @configuration
-      end
-
-      def test_do_not_grant_privileges_for_root_user
-        @configuration["username"] = "root"
-        @configuration["password"] = ""
-        ActiveRecord::Tasks::DatabaseTasks.create @configuration
-      end
-
-      def test_connection_established_as_normal_user
-        assert_permissions_granted_for("pat")
-        ActiveRecord::Base.expects(:establish_connection).returns do
-          ActiveRecord::Base.expects(:establish_connection).with(
-            "adapter"  => "mysql2",
-            "database" => "my-app-db",
-            "username" => "pat",
-            "password" => "secret"
-          )
-
-          raise @error
+      def test_raises_error
+        assert_raises(Mysql2::Error) do
+          ActiveRecord::Tasks::DatabaseTasks.create @configuration
         end
-
-        ActiveRecord::Tasks::DatabaseTasks.create @configuration
       end
-
-      def test_sends_output_to_stderr_when_other_errors
-        @error.stubs(:errno).returns(42)
-
-        $stderr.expects(:puts).at_least_once.returns(nil)
-
-        ActiveRecord::Tasks::DatabaseTasks.create @configuration
-      end
-
-      private
-
-        def assert_permissions_granted_for(db_user)
-          db_name = @configuration["database"]
-          db_password = @configuration["password"]
-          @connection.expects(:execute).with("GRANT ALL PRIVILEGES ON `#{db_name}`.* TO '#{db_user}'@'localhost' IDENTIFIED BY '#{db_password}' WITH GRANT OPTION;")
-        end
     end
 
     class MySQLDBDropTest < ActiveRecord::TestCase
diff --git a/activerecord/test/cases/unsafe_raw_sql_test.rb b/activerecord/test/cases/unsafe_raw_sql_test.rb
new file mode 100644
index 0000000000..72d4997d0b
--- /dev/null
+++ b/activerecord/test/cases/unsafe_raw_sql_test.rb
@@ -0,0 +1,299 @@
+# frozen_string_literal: true
+
+require "cases/helper"
+require "models/post"
+require "models/comment"
+
+class UnsafeRawSqlTest < ActiveRecord::TestCase
+  fixtures :posts, :comments
+
+  test "order: allows string column name" do
+    ids_expected = Post.order(Arel.sql("title")).pluck(:id)
+
+    ids_depr     = with_unsafe_raw_sql_deprecated { Post.order("title").pluck(:id) }
+    ids_disabled = with_unsafe_raw_sql_disabled   { Post.order("title").pluck(:id) }
+
+    assert_equal ids_expected, ids_depr
+    assert_equal ids_expected, ids_disabled
+  end
+
+  test "order: allows symbol column name" do
+    ids_expected = Post.order(Arel.sql("title")).pluck(:id)
+
+    ids_depr     = with_unsafe_raw_sql_deprecated { Post.order(:title).pluck(:id) }
+    ids_disabled = with_unsafe_raw_sql_disabled   { Post.order(:title).pluck(:id) }
+
+    assert_equal ids_expected, ids_depr
+    assert_equal ids_expected, ids_disabled
+  end
+
+  test "order: allows downcase symbol direction" do
+    ids_expected = Post.order(Arel.sql("title") => Arel.sql("asc")).pluck(:id)
+
+    ids_depr     = with_unsafe_raw_sql_deprecated { Post.order(title: :asc).pluck(:id) }
+    ids_disabled = with_unsafe_raw_sql_disabled   { Post.order(title: :asc).pluck(:id) }
+
+    assert_equal ids_expected, ids_depr
+    assert_equal ids_expected, ids_disabled
+  end
+
+  test "order: allows upcase symbol direction" do
+    ids_expected = Post.order(Arel.sql("title") => Arel.sql("ASC")).pluck(:id)
+
+    ids_depr     = with_unsafe_raw_sql_deprecated { Post.order(title: :ASC).pluck(:id) }
+    ids_disabled = with_unsafe_raw_sql_disabled   { Post.order(title: :ASC).pluck(:id) }
+
+    assert_equal ids_expected, ids_depr
+    assert_equal ids_expected, ids_disabled
+  end
+
+  test "order: allows string direction" do
+    ids_expected = Post.order(Arel.sql("title") => Arel.sql("asc")).pluck(:id)
+
+    ids_depr     = with_unsafe_raw_sql_deprecated { Post.order(title: "asc").pluck(:id) }
+    ids_disabled = with_unsafe_raw_sql_disabled   { Post.order(title: "asc").pluck(:id) }
+
+    assert_equal ids_expected, ids_depr
+    assert_equal ids_expected, ids_disabled
+  end
+
+  test "order: allows multiple columns" do
+    ids_expected = Post.order(Arel.sql("author_id"), Arel.sql("title")).pluck(:id)
+
+    ids_depr     = with_unsafe_raw_sql_deprecated { Post.order(:author_id, :title).pluck(:id) }
+    ids_disabled = with_unsafe_raw_sql_disabled   { Post.order(:author_id, :title).pluck(:id) }
+
+    assert_equal ids_expected, ids_depr
+    assert_equal ids_expected, ids_disabled
+  end
+
+  test "order: allows mixed" do
+    ids_expected = Post.order(Arel.sql("author_id"), Arel.sql("title") => Arel.sql("asc")).pluck(:id)
+
+    ids_depr     = with_unsafe_raw_sql_deprecated { Post.order(:author_id, title: :asc).pluck(:id) }
+    ids_disabled = with_unsafe_raw_sql_disabled   { Post.order(:author_id, title: :asc).pluck(:id) }
+
+    assert_equal ids_expected, ids_depr
+    assert_equal ids_expected, ids_disabled
+  end
+
+  test "order: allows table and column name" do
+    ids_expected = Post.order(Arel.sql("title")).pluck(:id)
+
+    ids_depr     = with_unsafe_raw_sql_deprecated { Post.order("posts.title").pluck(:id) }
+    ids_disabled = with_unsafe_raw_sql_disabled   { Post.order("posts.title").pluck(:id) }
+
+    assert_equal ids_expected, ids_depr
+    assert_equal ids_expected, ids_disabled
+  end
+
+  test "order: allows column name and direction in string" do
+    ids_expected = Post.order(Arel.sql("title desc")).pluck(:id)
+
+    ids_depr     = with_unsafe_raw_sql_deprecated { Post.order("title desc").pluck(:id) }
+    ids_disabled = with_unsafe_raw_sql_disabled   { Post.order("title desc").pluck(:id) }
+
+    assert_equal ids_expected, ids_depr
+    assert_equal ids_expected, ids_disabled
+  end
+
+  test "order: allows table name, column name and direction in string" do
+    ids_expected = Post.order(Arel.sql("title desc")).pluck(:id)
+
+    ids_depr     = with_unsafe_raw_sql_deprecated { Post.order("posts.title desc").pluck(:id) }
+    ids_disabled = with_unsafe_raw_sql_disabled   { Post.order("posts.title desc").pluck(:id) }
+
+    assert_equal ids_expected, ids_depr
+    assert_equal ids_expected, ids_disabled
+  end
+
+  test "order: disallows invalid column name" do
+    with_unsafe_raw_sql_disabled do
+      assert_raises(ActiveRecord::UnknownAttributeReference) do
+        Post.order("len(title) asc").pluck(:id)
+      end
+    end
+  end
+
+  test "order: disallows invalid direction" do
+    with_unsafe_raw_sql_disabled do
+      assert_raises(ArgumentError) do
+        Post.order(title: :foo).pluck(:id)
+      end
+    end
+  end
+
+  test "order: disallows invalid column with direction" do
+    with_unsafe_raw_sql_disabled do
+      assert_raises(ActiveRecord::UnknownAttributeReference) do
+        Post.order("len(title)" => :asc).pluck(:id)
+      end
+    end
+  end
+
+  test "order: always allows Arel" do
+    ids_depr     = with_unsafe_raw_sql_deprecated { Post.order(Arel.sql("length(title)")).pluck(:title) }
+    ids_disabled = with_unsafe_raw_sql_disabled   { Post.order(Arel.sql("length(title)")).pluck(:title) }
+
+    assert_equal ids_depr, ids_disabled
+  end
+
+  test "order: allows Arel.sql with binds" do
+    ids_expected = Post.order(Arel.sql("REPLACE(title, 'misc', 'zzzz'), id")).pluck(:id)
+
+    ids_depr     = with_unsafe_raw_sql_deprecated { Post.order([Arel.sql("REPLACE(title, ?, ?), id"), "misc", "zzzz"]).pluck(:id) }
+    ids_disabled = with_unsafe_raw_sql_disabled   { Post.order([Arel.sql("REPLACE(title, ?, ?), id"), "misc", "zzzz"]).pluck(:id) }
+
+    assert_equal ids_expected, ids_depr
+    assert_equal ids_expected, ids_disabled
+  end
+
+  test "order: disallows invalid bind statement" do
+    with_unsafe_raw_sql_disabled do
+      assert_raises(ActiveRecord::UnknownAttributeReference) do
+        Post.order(["REPLACE(title, ?, ?), id", "misc", "zzzz"]).pluck(:id)
+      end
+    end
+  end
+
+  test "order: disallows invalid Array arguments" do
+    with_unsafe_raw_sql_disabled do
+      assert_raises(ActiveRecord::UnknownAttributeReference) do
+        Post.order(["author_id", "length(title)"]).pluck(:id)
+      end
+    end
+  end
+
+  test "order: allows valid Array arguments" do
+    ids_expected = Post.order(Arel.sql("author_id, length(title)")).pluck(:id)
+
+    ids_depr     = with_unsafe_raw_sql_deprecated { Post.order(["author_id", Arel.sql("length(title)")]).pluck(:id) }
+    ids_disabled = with_unsafe_raw_sql_disabled   { Post.order(["author_id", Arel.sql("length(title)")]).pluck(:id) }
+
+    assert_equal ids_expected, ids_depr
+    assert_equal ids_expected, ids_disabled
+  end
+
+  test "order: logs deprecation warning for unrecognized column" do
+    with_unsafe_raw_sql_deprecated do
+      assert_deprecated(/Dangerous query method/) do
+        Post.order("length(title)")
+      end
+    end
+  end
+
+  test "pluck: allows string column name" do
+    titles_expected = Post.pluck(Arel.sql("title"))
+
+    titles_depr     = with_unsafe_raw_sql_deprecated { Post.pluck("title") }
+    titles_disabled = with_unsafe_raw_sql_disabled   { Post.pluck("title") }
+
+    assert_equal titles_expected, titles_depr
+    assert_equal titles_expected, titles_disabled
+  end
+
+  test "pluck: allows symbol column name" do
+    titles_expected = Post.pluck(Arel.sql("title"))
+
+    titles_depr     = with_unsafe_raw_sql_deprecated { Post.pluck(:title) }
+    titles_disabled = with_unsafe_raw_sql_disabled   { Post.pluck(:title) }
+
+    assert_equal titles_expected, titles_depr
+    assert_equal titles_expected, titles_disabled
+  end
+
+  test "pluck: allows multiple column names" do
+    values_expected = Post.pluck(Arel.sql("title"), Arel.sql("id"))
+
+    values_depr     = with_unsafe_raw_sql_deprecated { Post.pluck(:title, :id) }
+    values_disabled = with_unsafe_raw_sql_disabled   { Post.pluck(:title, :id) }
+
+    assert_equal values_expected, values_depr
+    assert_equal values_expected, values_disabled
+  end
+
+  test "pluck: allows column names with includes" do
+    values_expected = Post.includes(:comments).pluck(Arel.sql("title"), Arel.sql("id"))
+
+    values_depr     = with_unsafe_raw_sql_deprecated { Post.includes(:comments).pluck(:title, :id) }
+    values_disabled = with_unsafe_raw_sql_disabled   { Post.includes(:comments).pluck(:title, :id) }
+
+    assert_equal values_expected, values_depr
+    assert_equal values_expected, values_disabled
+  end
+
+  test "pluck: allows auto-generated attributes" do
+    values_expected = Post.pluck(Arel.sql("tags_count"))
+
+    values_depr     = with_unsafe_raw_sql_deprecated { Post.pluck(:tags_count) }
+    values_disabled = with_unsafe_raw_sql_disabled   { Post.pluck(:tags_count) }
+
+    assert_equal values_expected, values_depr
+    assert_equal values_expected, values_disabled
+  end
+
+  test "pluck: allows table and column names" do
+    titles_expected = Post.pluck(Arel.sql("title"))
+
+    titles_depr     = with_unsafe_raw_sql_deprecated { Post.pluck("posts.title") }
+    titles_disabled = with_unsafe_raw_sql_disabled   { Post.pluck("posts.title") }
+
+    assert_equal titles_expected, titles_depr
+    assert_equal titles_expected, titles_disabled
+  end
+
+  test "pluck: disallows invalid column name" do
+    with_unsafe_raw_sql_disabled do
+      assert_raises(ActiveRecord::UnknownAttributeReference) do
+        Post.pluck("length(title)")
+      end
+    end
+  end
+
+  test "pluck: disallows invalid column name amongst valid names" do
+    with_unsafe_raw_sql_disabled do
+      assert_raises(ActiveRecord::UnknownAttributeReference) do
+        Post.pluck(:title, "length(title)")
+      end
+    end
+  end
+
+  test "pluck: disallows invalid column names with includes" do
+    with_unsafe_raw_sql_disabled do
+      assert_raises(ActiveRecord::UnknownAttributeReference) do
+        Post.includes(:comments).pluck(:title, "length(title)")
+      end
+    end
+  end
+
+  test "pluck: always allows Arel" do
+    values_depr     = with_unsafe_raw_sql_deprecated { Post.includes(:comments).pluck(:title, Arel.sql("length(title)")) }
+    values_disabled = with_unsafe_raw_sql_disabled   { Post.includes(:comments).pluck(:title, Arel.sql("length(title)")) }
+
+    assert_equal values_depr, values_disabled
+  end
+
+  test "pluck: logs deprecation warning" do
+    with_unsafe_raw_sql_deprecated do
+      assert_deprecated(/Dangerous query method/) do
+        Post.includes(:comments).pluck(:title, "length(title)")
+      end
+    end
+  end
+
+  def with_unsafe_raw_sql_disabled(&blk)
+    with_config(:disabled, &blk)
+  end
+
+  def with_unsafe_raw_sql_deprecated(&blk)
+    with_config(:deprecated, &blk)
+  end
+
+  def with_config(new_value, &blk)
+    old_value = ActiveRecord::Base.allow_unsafe_raw_sql
+    ActiveRecord::Base.allow_unsafe_raw_sql = new_value
+    blk.call
+  ensure
+    ActiveRecord::Base.allow_unsafe_raw_sql = old_value
+  end
+end
diff --git a/activerecord/test/fixtures/other_posts.yml b/activerecord/test/fixtures/other_posts.yml
index 39ff763547..3e11a33802 100644
--- a/activerecord/test/fixtures/other_posts.yml
+++ b/activerecord/test/fixtures/other_posts.yml
@@ -5,3 +5,4 @@ second_welcome:
   author_id: 1
   title: Welcome to the another weblog
   body: It's really nice today
+  comments_count: 1
diff --git a/activerecord/test/fixtures/posts.yml b/activerecord/test/fixtures/posts.yml
index 86d46f753a..8d7e1e0ae7 100644
--- a/activerecord/test/fixtures/posts.yml
+++ b/activerecord/test/fixtures/posts.yml
@@ -28,6 +28,7 @@ sti_comments:
   author_id: 1
   title: sti comments
   body: hello
+  comments_count: 5
   type: Post
 
 sti_post_and_comments:
@@ -35,6 +36,7 @@ sti_post_and_comments:
   author_id: 1
   title: sti me
   body: hello
+  comments_count: 2
   type: StiPost
 
 sti_habtm:
@@ -50,6 +52,8 @@ eager_other:
   title: eager loading with OR'd conditions
   body: hello
   type: Post
+  comments_count: 1
+  tags_count: 3
 
 misc_by_bob:
   id: 8
@@ -57,6 +61,7 @@ misc_by_bob:
   title: misc post by bob
   body: hello
   type: Post
+  tags_count: 1
 
 misc_by_mary:
   id: 9
@@ -64,6 +69,7 @@ misc_by_mary:
   title: misc post by mary
   body: hello
   type: Post
+  tags_count: 1
 
 other_by_bob:
   id: 10
@@ -71,6 +77,7 @@ other_by_bob:
   title: other post by bob
   body: hello
   type: Post
+  tags_count: 1
 
 other_by_mary:
   id: 11
@@ -78,3 +85,4 @@ other_by_mary:
   title: other post by mary
   body: hello
   type: Post
+  tags_count: 1
diff --git a/activerecord/test/models/post.rb b/activerecord/test/models/post.rb
index 7f064bf3dd..780a2c17f5 100644
--- a/activerecord/test/models/post.rb
+++ b/activerecord/test/models/post.rb
@@ -319,5 +319,9 @@ class FakeKlass
     def arel_attribute(name, table)
       table[name]
     end
+
+    def enforce_raw_sql_whitelist(*args)
+      # noop
+    end
   end
 end