Fix Active Record 7.2 deprecation warnings

Fix: #573

lib/identity_cache.rb

@@ -117,27 +117,36 @@ def should_fill_cache? # :nodoc:
  !readonly
  end
 
- def should_use_cache? # :nodoc:
- ActiveRecord::Base.connection_handler.connection_pool_list(ActiveRecord::Base.current_role).none? do |pool|
- pool.active_connection? &&
- # Rails wraps each of your tests in a transaction, so that any changes
- # made to the database during the test can be rolled back afterwards.
- # These transactions are flagged as "unjoinable", which tries to make
- # your application behave as if they weren't there. In particular:
- #
- # - Opening another transaction during the test creates a savepoint,
- # which can be rolled back independently of the main transaction.
- # - When those nested transactions complete, any `after_commit`
- # callbacks for records modified during the transaction will run,
- # even though the changes haven't actually been committed yet.
- #
- # By ignoring unjoinable transactions, IdentityCache's behaviour
- # during your test suite will more closely match production.
- #
- # When there are no open transactions, `current_transaction` returns a
- # special `NullTransaction` object that is unjoinable, meaning we will
- # use the cache.
- pool.connection.current_transaction.joinable?
+ # Rails wraps each of your tests in a transaction, so that any changes
+ # made to the database during the test can be rolled back afterwards.
+ # These transactions are flagged as "unjoinable", which tries to make
+ # your application behave as if they weren't there. In particular:
+ #
+ # - Opening another transaction during the test creates a savepoint,
+ # which can be rolled back independently of the main transaction.
+ # - When those nested transactions complete, any `after_commit`
+ # callbacks for records modified during the transaction will run,
+ # even though the changes haven't actually been committed yet.
+ #
+ # By ignoring unjoinable transactions, IdentityCache's behaviour
+ # during your test suite will more closely match production.
+ #
+ # When there are no open transactions, `current_transaction` returns a
+ # special `NullTransaction` object that is unjoinable, meaning we will
+ # use the cache.
+ if ActiveRecord::ConnectionAdapters::ConnectionPool.method_defined?(:active_connection)
+ def should_use_cache? # :nodoc:
+ ActiveRecord::Base.connection_handler.connection_pool_list(ActiveRecord::Base.current_role).none? do |pool|
+ pool.active_connection? &&
+ pool.active_connection.current_transaction.joinable?
+ end
+ end
+ else
+ def should_use_cache? # :nodoc:
+ ActiveRecord::Base.connection_handler.connection_pool_list(ActiveRecord::Base.current_role).none? do |pool|
+ pool.active_connection? &&
+ pool.connection.current_transaction.joinable?
+ end
  end
  end