Clean with transaction not working for 2 databases

Bắt đầu với lib/database_cleaner/active_record/transaction.rb, đặc biệt là các đường dẫn start và clean của chiến lược transaction, rồi tái hiện thiết lập RSpec gồm hai example được mô tả trong issue. So sánh số lượng transaction được ghi log và trạng thái cơ sở dữ liệu của tenant trước và sau mỗi example. Được xem là hoàn tất khi sau cleanup, cơ sở dữ liệu của tenant không còn bệnh nhân nào từ example trước đó.

I've used DatabaseCleaner for several years (thanks!) without issues. But my current setup seems to not work properly.

Basic setup:

• Grape 0.19.2
• ActiveRecord 5.1.3 (+ otr-activerecord 1.2.4)
• RSpec 3.6.0
• DatabaseCleaner 1.6.1
• Posgres 9.5

On noteworthy thing about the app here is that it's using multiple databases: One main database and several tenant databases. In the test environment, this currently means two databases in total (main + test tenant).

Here's the test setup:

TEST_TENANT = 'the_tenant'
TEST_TENANT_API_KEY = SecureRandom.uuid.gsub('-', '')

RSpec.configure do |config|
  config.mock_with :rspec
  config.expect_with :rspec
  config.raise_errors_for_deprecations!
  # config.order = 'random'
  
  config.before(:suite) do
    ApiApp.establish_connection # ApiApp is connected to the main DB

    primary_cleaner.clean_with(:truncation)

    tenant = ApiApp.where(identifier: TEST_TENANT).first_or_create!(
      name: 'The tenant',
      api_key: TEST_TENANT_API_KEY
    )
    # force full recreate of tenant DB
    config = ActiveRecord::Base.configurations[tenant.identifier]
    ActiveRecord::Tasks::DatabaseTasks.drop(config) rescue nil
    ActiveRecord::Tasks::DatabaseTasks.create(config)
    ActiveRecord::Tasks::DatabaseTasks.load_schema(config, :sql, 'db/structure.sql')

    # seed it
    AppSetter.with(TEST_TENANT) do
      Dir["#{Dir.pwd}/spec/seeds/*.rb"].sort.each { |f| load f }
    end
  end

  config.before(:each) do |example|
    AppSetter.set(TEST_TENANT)

    puts ['[RSpec] start before', "number of patients: #{Patient.count}", Patient.connection.instance_variable_get(:@config)[:database]].inspect
    # primary_cleaner.start
    tenant_cleaner.start
    puts ['[RSpec] end before', "number of patients: #{Patient.count}", Patient.connection.instance_variable_get(:@config)[:database]].inspect
  end

  config.append_after(:each) do
    puts ['[RSpec] start append_after', "number of patients: #{Patient.count}", Patient.connection.instance_variable_get(:@config)[:database]].inspect
    # primary_cleaner.clean
    tenant_cleaner.clean
    puts ['[RSpec] end append_after', "number of patients: #{Patient.count}", Patient.connection.instance_variable_get(:@config)[:database]].inspect
    puts '-' * 100
  end

  private

  def primary_cleaner
    @primary_cleaner ||= cleaner_for(connection: ENV['RACK_ENV'].to_sym)
  end

  def tenant_cleaner
    @tenant_cleaner ||= cleaner_for(connection: TEST_TENANT.to_sym)
  end

  def cleaner_for(options)
    DatabaseCleaner[:active_record, options].tap { |cleaner| cleaner.strategy = :transaction }
  end
end

Now when I have 2 examples in RSpec which both use the same basic setup with a test patient (Patient.create!(email: '[email protected]', ...)), the uniqueness constraint on email fails because apparently the record exists already. The debugging code in the output (from the puts statements above) confirms this:

(1) ["[RSpec] start before", "number of patients: 0", "api_test_the_tenant"]
["[DatabaseCleaner] before start", "open transactions: 0", "api_test_the_tenant"]
(2) ["[DatabaseCleaner] after start", "open transactions: 1", "api_test_the_tenant"]
["[RSpec] end before", "number of patients: 0", "api_test_the_tenant"]
(3) ["[RSpec] start append_after", "number of patients: 1", "api_test_the_tenant"]
["[DatabaseCleaner] before clean", "open transactions: 1", "api_test_the_tenant"]
(4) ["[DatabaseCleaner] after clean", "open transactions: 0", "api_test_the_tenant"]
(5) ["[RSpec] end append_after", "number of patients: 1", "api_test_the_tenant"]
----------------------------------------------------------------------------------------------------
(6) ["[RSpec] start before", "number of patients: 1", "api_test_the_tenant"]
["[DatabaseCleaner] before start", "open transactions: 0", "api_test_the_tenant"]
["[DatabaseCleaner] after start", "open transactions: 1", "api_test_the_tenant"]
["[RSpec] end before", "number of patients: 1", "api_test_the_tenant"]
["[RSpec] start append_after", "number of patients: 1", "api_test_the_tenant"]
["[DatabaseCleaner] before clean", "open transactions: 1", "api_test_the_tenant"]
["[DatabaseCleaner] after clean", "open transactions: 0", "api_test_the_tenant"]
["[RSpec] end append_after", "number of patients: 1", "api_test_the_tenant"]
----------------------------------------------------------------------------------------------------

(I've numbered some lines to make it easier to follow. The [DatabaseCleaner] output comes from some puts statements I've put in the corresponding strategy in https://github.com/DatabaseCleaner/database_cleaner/blob/master/lib/database_cleaner/active_record/transaction.rb.)

(1) Before the first example (in the first before block), there are 0 patients in the tenant database => expected.
(2) tenant_cleaner.start has caused an open transaction in the tenant database => expected.
(3) Running the example has created a patient in the tenant database => expected.
(4) tenant_cleaner.clean rolls back the transaction => expected.
(5) There is still 1 patient in the tenant database => this is NOT expected.
(6) The before block of the next example confirms that 1 patient has remained in the tenant database => this is NOT expected.

Commenting in/out the cleaning of the primary database doesn't change anything (I wouldn't have expected it to either, but I tried it nonetheless).

Does anyone have any insights as to what's going wrong here?

Thanks a lot in advance.