# frozen_string_literal: true require "cases/helper" require "models/topic" require "models/reply" require "models/developer" require "models/computer" require "models/book" require "models/author" require "models/post" require "models/movie" class TransactionTest < ActiveRecord::TestCase self.use_transactional_tests = false fixtures :topics, :developers, :authors, :author_addresses, :posts def setup @first, @second = Topic.find(1, 2).sort_by(&:id) end def test_rollback_dirty_changes topic = topics(:fifth) ActiveRecord::Base.transaction do topic.update(title: "Ruby on Rails") raise ActiveRecord::Rollback end title_change = ["The Fifth Topic of the day", "Ruby on Rails"] assert_equal title_change, topic.changes["title"] end def test_rollback_dirty_changes_multiple_saves topic = topics(:fifth) ActiveRecord::Base.transaction do topic.update(title: "Ruby on Rails") topic.update(title: "Another Title") raise ActiveRecord::Rollback end title_change = ["The Fifth Topic of the day", "Another Title"] assert_equal title_change, topic.changes["title"] end def test_rollback_dirty_changes_then_retry_save topic = topics(:fifth) ActiveRecord::Base.transaction do topic.update(title: "Ruby on Rails") raise ActiveRecord::Rollback end title_change = ["The Fifth Topic of the day", "Ruby on Rails"] assert_equal title_change, topic.changes["title"] assert topic.save assert_equal title_change, topic.saved_changes["title"] assert_equal topic.title, topic.reload.title end def test_rollback_dirty_changes_then_retry_save_on_new_record topic = Topic.new(title: "Ruby on Rails") ActiveRecord::Base.transaction do topic.save raise ActiveRecord::Rollback end title_change = [nil, "Ruby on Rails"] assert_equal title_change, topic.changes["title"] assert topic.save assert_equal title_change, topic.saved_changes["title"] assert_equal topic.title, topic.reload.title end def test_rollback_dirty_changes_then_retry_save_on_new_record_with_autosave_association author = Author.new(name: "DHH") book = Book.create! author.books << book author.transaction do author.save! raise ActiveRecord::Rollback end author.save! assert_equal author, book.reload.author end def test_persisted_in_a_model_with_custom_primary_key_after_failed_save movie = Movie.create assert_not_predicate movie, :persisted? end def test_raise_after_destroy assert_not_predicate @first, :frozen? assert_raises(RuntimeError) do Topic.transaction do @first.destroy assert_predicate @first, :frozen? raise end end assert_not_predicate @first, :frozen? end def test_successful Topic.transaction do @first.approved = true @second.approved = false @first.save @second.save end assert_predicate Topic.find(1), :approved?, "First should have been approved" assert_not_predicate Topic.find(2), :approved?, "Second should have been unapproved" end def transaction_with_return Topic.transaction do @first.approved = true @second.approved = false @first.save @second.save return end end def test_add_to_null_transaction topic = Topic.new topic.send(:add_to_transaction) end def test_successful_with_return committed = false Topic.connection.class_eval do alias :real_commit_db_transaction :commit_db_transaction define_method(:commit_db_transaction) do committed = true real_commit_db_transaction end end assert_deprecated do transaction_with_return end assert committed assert_predicate Topic.find(1), :approved?, "First should have been approved" assert_not_predicate Topic.find(2), :approved?, "Second should have been unapproved" ensure Topic.connection.class_eval do remove_method :commit_db_transaction alias :commit_db_transaction :real_commit_db_transaction rescue nil end end def test_deprecation_on_ruby_timeout assert_deprecated do catch do |timeout| Topic.transaction do @first.approved = true @first.save! throw timeout end end end assert Topic.find(1).approved?, "First should have been approved" end def test_early_return_from_transaction assert_not_deprecated do @first.with_lock do break end end end def test_number_of_transactions_in_commit num = nil Topic.connection.class_eval do alias :real_commit_db_transaction :commit_db_transaction define_method(:commit_db_transaction) do num = transaction_manager.open_transactions real_commit_db_transaction end end Topic.transaction do @first.approved = true @first.save! end assert_equal 0, num ensure Topic.connection.class_eval do remove_method :commit_db_transaction alias :commit_db_transaction :real_commit_db_transaction rescue nil end end def test_successful_with_instance_method @first.transaction do @first.approved = true @second.approved = false @first.save @second.save end assert_predicate Topic.find(1), :approved?, "First should have been approved" assert_not_predicate Topic.find(2), :approved?, "Second should have been unapproved" end def test_failing_on_exception begin Topic.transaction do @first.approved = true @second.approved = false @first.save @second.save raise "Bad things!" end rescue # caught it end assert_predicate @first, :approved?, "First should still be changed in the objects" assert_not_predicate @second, :approved?, "Second should still be changed in the objects" assert_not_predicate Topic.find(1), :approved?, "First shouldn't have been approved" assert_predicate Topic.find(2), :approved?, "Second should still be approved" end def test_raising_exception_in_callback_rollbacks_in_save def @first.after_save_for_transaction raise "Make the transaction rollback" end @first.approved = true e = assert_raises(RuntimeError) { @first.save } assert_equal "Make the transaction rollback", e.message assert_not_predicate Topic.find(1), :approved? end def test_rolling_back_in_a_callback_rollbacks_before_save def @first.before_save_for_transaction raise ActiveRecord::Rollback end assert_not_predicate @first, :approved? assert_not_called(@first, :rolledback!) do Topic.transaction do @first.approved = true @first.save! end end assert_not_predicate Topic.find(@first.id), :approved?, "Should not commit the approved flag" end def test_raising_exception_in_nested_transaction_restore_state_in_save topic = Topic.new def topic.after_save_for_transaction raise "Make the transaction rollback" end assert_raises(RuntimeError) do Topic.transaction { topic.save } end assert_predicate topic, :new_record?, "#{topic.inspect} should be new record" end def test_transaction_state_is_cleared_when_record_is_persisted author = Author.create! name: "foo" author.name = nil assert_not author.save assert_not_predicate author, :new_record? end def test_update_should_rollback_on_failure author = Author.find(1) posts_count = author.posts.size assert posts_count > 0 status = author.update(name: nil, post_ids: []) assert_not status assert_equal posts_count, author.posts.reload.size end def test_update_should_rollback_on_failure! author = Author.find(1) posts_count = author.posts.size assert posts_count > 0 assert_raise(ActiveRecord::RecordInvalid) do author.update!(name: nil, post_ids: []) end assert_equal posts_count, author.posts.reload.size end def test_cancellation_from_before_destroy_rollbacks_in_destroy add_cancelling_before_destroy_with_db_side_effect_to_topic @first nbooks_before_destroy = Book.count status = @first.destroy assert_not status @first.reload assert_equal nbooks_before_destroy, Book.count end %w(validation save).each do |filter| define_method("test_cancellation_from_before_filters_rollbacks_in_#{filter}") do send("add_cancelling_before_#{filter}_with_db_side_effect_to_topic", @first) nbooks_before_save = Book.count original_author_name = @first.author_name @first.author_name += "_this_should_not_end_up_in_the_db" status = @first.save assert_not status assert_equal original_author_name, @first.reload.author_name assert_equal nbooks_before_save, Book.count end define_method("test_cancellation_from_before_filters_rollbacks_in_#{filter}!") do send("add_cancelling_before_#{filter}_with_db_side_effect_to_topic", @first) nbooks_before_save = Book.count original_author_name = @first.author_name @first.author_name += "_this_should_not_end_up_in_the_db" begin @first.save! rescue ActiveRecord::RecordInvalid, ActiveRecord::RecordNotSaved end assert_equal original_author_name, @first.reload.author_name assert_equal nbooks_before_save, Book.count end end def test_callback_rollback_in_create topic = Class.new(Topic) { def after_create_for_transaction raise "Make the transaction rollback" end } new_topic = topic.new(title: "A new topic", author_name: "Ben", author_email_address: "ben@example.com", written_on: "2003-07-16t15:28:11.2233+01:00", last_read: "2004-04-15", bonus_time: "2005-01-30t15:28:00.00+01:00", content: "Have a nice day", approved: false) new_record_snapshot = !new_topic.persisted? id_present = new_topic.has_attribute?(Topic.primary_key) id_snapshot = new_topic.id # Make sure the second save gets the after_create callback called. 2.times do new_topic.approved = true e = assert_raises(RuntimeError) { new_topic.save } assert_equal "Make the transaction rollback", e.message assert_equal new_record_snapshot, !new_topic.persisted?, "The topic should have its old persisted value" if id_snapshot.nil? assert_nil new_topic.id, "The topic should have its old id" else assert_equal id_snapshot, new_topic.id, "The topic should have its old id" end assert_equal id_present, new_topic.has_attribute?(Topic.primary_key) end end def test_callback_rollback_in_create_with_record_invalid_exception topic = Class.new(Topic) { def after_create_for_transaction raise ActiveRecord::RecordInvalid.new(Author.new) end } new_topic = topic.create(title: "A new topic") assert_not new_topic.persisted?, "The topic should not be persisted" assert_nil new_topic.id, "The topic should not have an ID" end def test_callback_rollback_in_create_with_rollback_exception topic = Class.new(Topic) { def after_create_for_transaction raise ActiveRecord::Rollback end } new_topic = topic.create(title: "A new topic") assert_not new_topic.persisted?, "The topic should not be persisted" assert_nil new_topic.id, "The topic should not have an ID" end def test_nested_explicit_transactions Topic.transaction do Topic.transaction do @first.approved = true @second.approved = false @first.save @second.save end end assert Topic.find(1).approved?, "First should have been approved" assert_not Topic.find(2).approved?, "Second should have been unapproved" end def test_nested_transaction_with_new_transaction_applies_parent_state_on_rollback topic_one = Topic.new(title: "A new topic") topic_two = Topic.new(title: "Another new topic") Topic.transaction do topic_one.save Topic.transaction(requires_new: true) do topic_two.save assert_predicate topic_one, :persisted? assert_predicate topic_two, :persisted? end raise ActiveRecord::Rollback end assert_not_predicate topic_one, :persisted? assert_not_predicate topic_two, :persisted? end def test_nested_transaction_without_new_transaction_applies_parent_state_on_rollback topic_one = Topic.new(title: "A new topic") topic_two = Topic.new(title: "Another new topic") Topic.transaction do topic_one.save Topic.transaction do topic_two.save assert_predicate topic_one, :persisted? assert_predicate topic_two, :persisted? end raise ActiveRecord::Rollback end assert_not_predicate topic_one, :persisted? assert_not_predicate topic_two, :persisted? end def test_double_nested_transaction_applies_parent_state_on_rollback topic_one = Topic.new(title: "A new topic") topic_two = Topic.new(title: "Another new topic") topic_three = Topic.new(title: "Another new topic of course") Topic.transaction do topic_one.save Topic.transaction do topic_two.save Topic.transaction do topic_three.save end end assert_predicate topic_one, :persisted? assert_predicate topic_two, :persisted? assert_predicate topic_three, :persisted? raise ActiveRecord::Rollback end assert_not_predicate topic_one, :persisted? assert_not_predicate topic_two, :persisted? assert_not_predicate topic_three, :persisted? end def test_manually_rolling_back_a_transaction Topic.transaction do @first.approved = true @second.approved = false @first.save @second.save raise ActiveRecord::Rollback end assert @first.approved?, "First should still be changed in the objects" assert_not @second.approved?, "Second should still be changed in the objects" assert_not Topic.find(1).approved?, "First shouldn't have been approved" assert Topic.find(2).approved?, "Second should still be approved" end def test_invalid_keys_for_transaction assert_raise ArgumentError do Topic.transaction nested: true do end end end def test_force_savepoint_in_nested_transaction Topic.transaction do @first.approved = true @second.approved = false @first.save! @second.save! begin Topic.transaction requires_new: true do @first.approved = false @first.save! raise end rescue end end assert_predicate @first.reload, :approved? assert_not_predicate @second.reload, :approved? end if Topic.connection.supports_savepoints? def test_force_savepoint_on_instance @first.transaction do @first.approved = true @second.approved = false @first.save! @second.save! begin @second.transaction requires_new: true do @first.approved = false @first.save! raise end rescue end end assert_predicate @first.reload, :approved? assert_not_predicate @second.reload, :approved? end if Topic.connection.supports_savepoints? def test_no_savepoint_in_nested_transaction_without_force Topic.transaction do @first.approved = true @second.approved = false @first.save! @second.save! begin Topic.transaction do @first.approved = false @first.save! raise end rescue end end assert_not_predicate @first.reload, :approved? assert_not_predicate @second.reload, :approved? end if Topic.connection.supports_savepoints? def test_many_savepoints Topic.transaction do @first.content = "One" @first.save! begin Topic.transaction requires_new: true do @first.content = "Two" @first.save! begin Topic.transaction requires_new: true do @first.content = "Three" @first.save! begin Topic.transaction requires_new: true do @first.content = "Four" @first.save! raise end rescue end @three = @first.reload.content raise end rescue end @two = @first.reload.content raise end rescue end @one = @first.reload.content end assert_equal "One", @one assert_equal "Two", @two assert_equal "Three", @three end if Topic.connection.supports_savepoints? def test_using_named_savepoints Topic.transaction do @first.approved = true @first.save! Topic.connection.create_savepoint("first") @first.approved = false @first.save! Topic.connection.rollback_to_savepoint("first") assert_predicate @first.reload, :approved? @first.approved = false @first.save! Topic.connection.release_savepoint("first") assert_not_predicate @first.reload, :approved? end end if Topic.connection.supports_savepoints? def test_releasing_named_savepoints Topic.transaction do Topic.connection.create_savepoint("another") Topic.connection.release_savepoint("another") # The savepoint is now gone and we can't remove it again. assert_raises(ActiveRecord::StatementInvalid) do Topic.connection.release_savepoint("another") end end end def test_savepoints_name Topic.transaction do assert_nil Topic.connection.current_savepoint_name assert_nil Topic.connection.current_transaction.savepoint_name Topic.transaction(requires_new: true) do assert_equal "active_record_1", Topic.connection.current_savepoint_name assert_equal "active_record_1", Topic.connection.current_transaction.savepoint_name Topic.transaction(requires_new: true) do assert_equal "active_record_2", Topic.connection.current_savepoint_name assert_equal "active_record_2", Topic.connection.current_transaction.savepoint_name end assert_equal "active_record_1", Topic.connection.current_savepoint_name assert_equal "active_record_1", Topic.connection.current_transaction.savepoint_name end end end def test_rollback_when_commit_raises assert_called(Topic.connection, :begin_db_transaction) do Topic.connection.stub(:commit_db_transaction, -> { raise("OH NOES") }) do assert_called(Topic.connection, :rollback_db_transaction) do e = assert_raise RuntimeError do Topic.transaction do Topic.connection.materialize_transactions end end assert_equal "OH NOES", e.message end end end end def test_rollback_when_saving_a_frozen_record topic = Topic.new(title: "test") topic.freeze e = assert_raise(FrozenError) { topic.save } # Not good enough, but we can't do much # about it since there is no specific error # for frozen objects. assert_match(/frozen/i, e.message) assert_not topic.persisted?, "not persisted" assert_nil topic.id assert topic.frozen?, "not frozen" end def test_rollback_when_thread_killed return if in_memory_db? queue = Queue.new thread = Thread.new do Topic.transaction do @first.approved = true @second.approved = false @first.save queue.push nil sleep @second.save end end queue.pop thread.kill thread.join assert @first.approved?, "First should still be changed in the objects" assert_not @second.approved?, "Second should still be changed in the objects" assert_not Topic.find(1).approved?, "First shouldn't have been approved" assert Topic.find(2).approved?, "Second should still be approved" end def test_restore_active_record_state_for_all_records_in_a_transaction topic_without_callbacks = Class.new(ActiveRecord::Base) do self.table_name = "topics" end topic_1 = Topic.new(title: "test_1") topic_2 = Topic.new(title: "test_2") topic_3 = topic_without_callbacks.new(title: "test_3") Topic.transaction do assert topic_1.save assert topic_2.save assert topic_3.save @first.save @second.destroy assert topic_1.persisted?, "persisted" assert_not_nil topic_1.id assert topic_2.persisted?, "persisted" assert_not_nil topic_2.id assert topic_3.persisted?, "persisted" assert_not_nil topic_3.id assert @first.persisted?, "persisted" assert_not_nil @first.id assert @second.destroyed?, "destroyed" raise ActiveRecord::Rollback end assert_not topic_1.persisted?, "not persisted" assert_nil topic_1.id assert_not topic_2.persisted?, "not persisted" assert_nil topic_2.id assert_not topic_3.persisted?, "not persisted" assert_nil topic_3.id assert @first.persisted?, "persisted" assert_not_nil @first.id assert_not @second.destroyed?, "not destroyed" end def test_restore_frozen_state_after_double_destroy topic = Topic.create reply = topic.replies.create Topic.transaction do topic.destroy # calls #destroy on reply (since dependent: destroy) reply.destroy raise ActiveRecord::Rollback end assert_not_predicate reply, :frozen? assert_not_predicate topic, :frozen? end def test_restore_new_record_after_double_save topic = Topic.new Topic.transaction do topic.save! topic.save! raise ActiveRecord::Rollback end assert_nil topic.id assert_predicate topic, :new_record? end def test_dont_restore_new_record_in_subsequent_transaction topic = Topic.new Topic.transaction do topic.save! topic.save! end Topic.transaction do topic.save! raise ActiveRecord::Rollback end assert_predicate topic, :persisted? assert_not_predicate topic, :new_record? end def test_restore_previously_new_record_after_double_save topic = Topic.create! Topic.transaction do topic.save! topic.save! raise ActiveRecord::Rollback end assert_predicate topic, :previously_new_record? end def test_restore_id_after_rollback topic = Topic.new Topic.transaction do topic.save! raise ActiveRecord::Rollback end assert_nil topic.id end def test_restore_custom_primary_key_after_rollback movie = Movie.new(name: "foo") Movie.transaction do movie.save! raise ActiveRecord::Rollback end assert_nil movie.movieid end def test_assign_id_after_rollback topic = Topic.create! Topic.transaction do topic.save! raise ActiveRecord::Rollback end topic.id = nil assert_nil topic.id end def test_assign_custom_primary_key_after_rollback movie = Movie.create!(name: "foo") Movie.transaction do movie.save! raise ActiveRecord::Rollback end movie.movieid = nil assert_nil movie.movieid end def test_read_attribute_after_rollback topic = Topic.new Topic.transaction do topic.save! raise ActiveRecord::Rollback end assert_nil topic.read_attribute(:id) end def test_read_attribute_with_custom_primary_key_after_rollback movie = Movie.new(name: "foo") Movie.transaction do movie.save! raise ActiveRecord::Rollback end assert_nil movie.read_attribute(:movieid) end def test_write_attribute_after_rollback topic = Topic.create! Topic.transaction do topic.save! raise ActiveRecord::Rollback end topic.write_attribute(:id, nil) assert_nil topic.id end def test_write_attribute_with_custom_primary_key_after_rollback movie = Movie.create!(name: "foo") Movie.transaction do movie.save! raise ActiveRecord::Rollback end movie.write_attribute(:movieid, nil) assert_nil movie.movieid end def test_rollback_of_frozen_records topic = Topic.create.freeze Topic.transaction do topic.destroy raise ActiveRecord::Rollback end assert topic.frozen?, "frozen" end def test_rollback_for_freshly_persisted_records topic = Topic.create Topic.transaction do topic.destroy raise ActiveRecord::Rollback end assert topic.persisted?, "persisted" end def test_sqlite_add_column_in_transaction return true unless current_adapter?(:SQLite3Adapter) # Test first if column creation/deletion works correctly when no # transaction is in place. # # We go back to the connection for the column queries because # Topic.columns is cached and won't report changes to the DB assert_nothing_raised do Topic.reset_column_information Topic.connection.add_column("topics", "stuff", :string) assert_includes Topic.column_names, "stuff" Topic.reset_column_information Topic.connection.remove_column("topics", "stuff") assert_not_includes Topic.column_names, "stuff" end if Topic.connection.supports_ddl_transactions? assert_nothing_raised do Topic.transaction { Topic.connection.add_column("topics", "stuff", :string) } end else Topic.transaction do assert_raise(ActiveRecord::StatementInvalid) { Topic.connection.add_column("topics", "stuff", :string) } raise ActiveRecord::Rollback end end ensure begin Topic.connection.remove_column("topics", "stuff") rescue ensure Topic.reset_column_information end end def test_transactions_state_from_rollback connection = Topic.connection transaction = ActiveRecord::ConnectionAdapters::TransactionManager.new(connection).begin_transaction assert_predicate transaction, :open? assert_not_predicate transaction.state, :rolledback? assert_not_predicate transaction.state, :committed? transaction.rollback assert_predicate transaction.state, :rolledback? assert_not_predicate transaction.state, :committed? end def test_transactions_state_from_commit connection = Topic.connection transaction = ActiveRecord::ConnectionAdapters::TransactionManager.new(connection).begin_transaction assert_predicate transaction, :open? assert_not_predicate transaction.state, :rolledback? assert_not_predicate transaction.state, :committed? transaction.commit assert_not_predicate transaction.state, :rolledback? assert_predicate transaction.state, :committed? end def test_mark_transaction_state_as_committed connection = Topic.connection transaction = ActiveRecord::ConnectionAdapters::TransactionManager.new(connection).begin_transaction transaction.rollback assert_equal :committed, transaction.state.commit! end def test_mark_transaction_state_as_rolledback connection = Topic.connection transaction = ActiveRecord::ConnectionAdapters::TransactionManager.new(connection).begin_transaction transaction.commit assert_equal :rolledback, transaction.state.rollback! end def test_mark_transaction_state_as_nil connection = Topic.connection transaction = ActiveRecord::ConnectionAdapters::TransactionManager.new(connection).begin_transaction transaction.commit assert_nil transaction.state.nullify! end def test_transaction_rollback_with_primarykeyless_tables connection = ActiveRecord::Base.connection connection.create_table(:transaction_without_primary_keys, force: true, id: false) do |t| t.integer :thing_id end klass = Class.new(ActiveRecord::Base) do self.table_name = "transaction_without_primary_keys" after_commit { } # necessary to trigger the has_transactional_callbacks branch end assert_no_difference(-> { klass.count }) do ActiveRecord::Base.transaction do klass.create! raise ActiveRecord::Rollback end end ensure connection.drop_table "transaction_without_primary_keys", if_exists: true end def test_empty_transaction_is_not_materialized assert_no_queries do Topic.transaction { } end end def test_unprepared_statement_materializes_transaction assert_sql(/BEGIN/i, /COMMIT/i) do Topic.transaction { Topic.where("1=1").first } end end if ActiveRecord::Base.connection.prepared_statements def test_prepared_statement_materializes_transaction Topic.first assert_sql(/BEGIN/i, /COMMIT/i) do Topic.transaction { Topic.first } end end end def test_savepoint_does_not_materialize_transaction assert_no_queries do Topic.transaction do Topic.transaction(requires_new: true) { } end end end def test_raising_does_not_materialize_transaction assert_raise(RuntimeError) do assert_no_queries do Topic.transaction { raise } end end end def test_accessing_raw_connection_materializes_transaction assert_sql(/BEGIN/i, /COMMIT/i) do Topic.transaction { Topic.connection.raw_connection } end end def test_accessing_raw_connection_disables_lazy_transactions Topic.connection.raw_connection assert_sql(/BEGIN/i, /COMMIT/i) do Topic.transaction { } end end def test_checking_in_connection_reenables_lazy_transactions connection = Topic.connection_pool.checkout connection.raw_connection Topic.connection_pool.checkin connection assert_no_queries do connection.transaction { } end end def test_transactions_can_be_manually_materialized assert_sql(/BEGIN/i, /COMMIT/i) do Topic.transaction do Topic.connection.materialize_transactions end end end private %w(validation save destroy).each do |filter| define_method("add_cancelling_before_#{filter}_with_db_side_effect_to_topic") do |topic| meta = class << topic; self; end meta.send("define_method", "before_#{filter}_for_transaction") do Book.create throw(:abort) end end end end class TransactionsWithTransactionalFixturesTest < ActiveRecord::TestCase self.use_transactional_tests = true fixtures :topics def test_automatic_savepoint_in_outer_transaction @first = Topic.find(1) begin Topic.transaction do @first.approved = true @first.save! raise end rescue assert_not_predicate @first.reload, :approved? end end def test_no_automatic_savepoint_for_inner_transaction @first = Topic.find(1) Topic.transaction do @first.approved = true @first.save! begin Topic.transaction do @first.approved = false @first.save! raise end rescue end end assert_not_predicate @first.reload, :approved? end end if Topic.connection.supports_savepoints? if ActiveRecord::Base.connection.supports_transaction_isolation? && !current_adapter?(:SQLite3Adapter) class ConcurrentTransactionTest < TransactionTest # This will cause transactions to overlap and fail unless they are performed on # separate database connections. def test_transaction_per_thread threads = 3.times.map do Thread.new do Topic.transaction do topic = Topic.find(1) topic.approved = !topic.approved? assert topic.save! topic.approved = !topic.approved? assert topic.save! end Topic.connection.close end end threads.each(&:join) end # Test for dirty reads among simultaneous transactions. def test_transaction_isolation__read_committed # Should be invariant. original_salary = Developer.find(1).salary temporary_salary = 200000 assert_nothing_raised do threads = (1..3).map do Thread.new do Developer.transaction do # Expect original salary. dev = Developer.find(1) assert_equal original_salary, dev.salary dev.salary = temporary_salary dev.save! # Expect temporary salary. dev = Developer.find(1) assert_equal temporary_salary, dev.salary dev.salary = original_salary dev.save! # Expect original salary. dev = Developer.find(1) assert_equal original_salary, dev.salary end Developer.connection.close end end # Keep our eyes peeled. threads << Thread.new do 10.times do sleep 0.05 Developer.transaction do # Always expect original salary. assert_equal original_salary, Developer.find(1).salary end end Developer.connection.close end threads.each(&:join) end assert_equal original_salary, Developer.find(1).salary end end end