Provides some helpers to deal with testing log subscribers by setting up notifications. Take for instance Active Record subscriber tests:
class SyncLogSubscriberTest < ActiveSupport::TestCase include ActiveSupport::LogSubscriber::TestHelper setup do ActiveRecord::LogSubscriber.attach_to(:active_record) end def test_basic_query_logging Developer.all.to_a wait assert_equal 1, @logger.logged(:debug).size assert_match(/Developer Load/, @logger.logged(:debug).last) assert_match(/SELECT \* FROM "developers"/, @logger.logged(:debug).last) end end
All you need to do is to ensure that your log subscriber is added to Rails::Subscriber, as in the second line of the code above. The test helpers are responsible for setting up the queue, subscriptions and turning colors in logs off.
The messages are available in the @logger instance, which is a logger with limited powers (it actually does not send anything to your output), and you can collect them doing @logger.logged(level), where level is the level used in logging, like info, debug, warn and so on.
Overwrite if you use another logger in your log subscriber.
def logger ActiveRecord::Base.logger = @logger end
# File activesupport/lib/active_support/log_subscriber/test_helper.rb, line 99 def set_logger(logger) ActiveSupport::LogSubscriber.logger = logger end
Wait notifications to be published.
# File activesupport/lib/active_support/log_subscriber/test_helper.rb, line 90 def wait @notifier.wait end