diff options
| -rw-r--r-- | railties/lib/rails/subscriber.rb | 96 | ||||
| -rw-r--r-- | railties/test/subscriber_test.rb | 102 |
2 files changed, 198 insertions, 0 deletions
diff --git a/railties/lib/rails/subscriber.rb b/railties/lib/rails/subscriber.rb new file mode 100644 index 0000000000..f98dec738d --- /dev/null +++ b/railties/lib/rails/subscriber.rb @@ -0,0 +1,96 @@ +require 'active_support/core_ext/class/inheritable_attributes' +require 'active_support/notifications' + +module Rails + # Rails::Subscriber is an object set to consume ActiveSupport::Notifications + # on initialization with solely purpose of logging. The subscriber dispatches + # notifications to a regirested object based on its given namespace. + # + # An example would be ActiveRecord subscriber responsible for logging queries: + # + # module ActiveRecord + # class Railtie + # class Subscriber < Rails::Subscriber + # def sql(event) + # "#{event.payload[:name]} (#{event.duration}) #{event.payload[:sql]}" + # end + # end + # end + # end + # + # It's finally registed as: + # + # Rails::Subscriber.add :active_record, ActiveRecord::Railtie::Subscriber.new + # + # So whenever a "active_record.sql" notification arrive to Rails::Subscriber, + # it will properly dispatch the event (ActiveSupport::Notifications::Event) to + # the sql method. + # + # This is useful because it avoids spanning several subscribers just for logging + # purposes(which slows down the main thread). Besides of providing a centralized + # facility on top of Rails.logger. + # + # Finally, Subscriber some helpers to deal with logging, like managing console colors. + class Subscriber + cattr_accessor :colorize_logging, :instance_writer => false + self.colorize_logging = true + + # Embed in a String to clear all previous ANSI sequences. + CLEAR = "\e[0m" + BOLD = "\e[1m" + + # Colors + BLACK = "\e[30m" + RED = "\e[31m" + GREEN = "\e[32m" + YELLOW = "\e[33m" + BLUE = "\e[34m" + MAGENTA = "\e[35m" + CYAN = "\e[36m" + WHITE = "\e[37m" + + def self.add(namespace, subscriber) + subscribers[namespace.to_sym] = subscriber + end + + def self.subscribers + @subscribers ||= {} + end + + def self.dispatch(args) + namespace, name = args[0].split(".") + subscriber = subscribers[namespace.to_sym] + + if subscriber.respond_to?(name) && subscriber.logger + subscriber.send(name, ActiveSupport::Notifications::Event.new(*args)) + end + end + + # By default, we use the Rails.logger for logging. + def logger + Rails.logger + end + + protected + + %w(info debug warn error fatal unknown).each do |level| + class_eval <<-METHOD, __FILE__, __LINE__ + 1 + def #{level}(*args, &block) + logger.#{level}(*args, &block) + end + METHOD + end + + # Set color by using a string or one of the defined constants. If a third + # option is set to true, it also adds bold to the string. This is based + # on Highline implementation and it automatically appends CLEAR to the end + # of the returned String. + # + def color(text, color, bold=false) + return text unless colorize_logging + color = self.class.const_get(color.to_s.upcase) if color.is_a?(Symbol) + bold = bold ? BOLD : "" + "#{bold}#{color}#{text}#{CLEAR}" + end + end +end
\ No newline at end of file diff --git a/railties/test/subscriber_test.rb b/railties/test/subscriber_test.rb new file mode 100644 index 0000000000..ada40e2d2b --- /dev/null +++ b/railties/test/subscriber_test.rb @@ -0,0 +1,102 @@ +require 'abstract_unit' +require 'rails/subscriber' + +Thread.abort_on_exception = true + +class MockLogger + def initialize + @logged = Hash.new { |h,k| h[k] = [] } + end + + def method_missing(level, message) + @logged[level] << message + end + + def logged(level) + @logged[level].compact.map { |l| l.to_s.strip } + end +end + +ActiveSupport::Notifications.subscribe do |*args| + Rails::Subscriber.dispatch(args) +end + +class MySubscriber < Rails::Subscriber + def some_event(event) + info event.name + end + + def foo(event) + debug "debug" + info "info" + warn "warn" + end + + def bar(event) + info "#{color("cool", :red)}, #{color("isn't it?", :blue, true)}" + end +end + +class SubscriberTest < ActiveSupport::TestCase + def setup + @logger = MockLogger.new + @previous_logger, Rails.logger = Rails.logger, @logger + @subscriber = MySubscriber.new + wait + end + + def teardown + Rails.logger = @previous_logger + Rails::Subscriber.subscribers.clear + end + + def instrument(*args, &block) + ActiveSupport::Notifications.instrument(*args, &block) + end + + def wait + ActiveSupport::Notifications.notifier.wait + end + + def test_proxies_method_to_rails_logger + @subscriber.foo(nil) + assert_equal %w(debug), @logger.logged(:debug) + assert_equal %w(info), @logger.logged(:info) + assert_equal %w(warn), @logger.logged(:warn) + end + + def test_set_color_for_messages + @subscriber.bar(nil) + assert_equal "\e[31mcool\e[0m, \e[1m\e[34misn't it?\e[0m", @logger.logged(:info).last + end + + def test_does_not_set_color_if_colorize_logging_is_set_to_false + Rails::Subscriber.colorize_logging = false + @subscriber.bar(nil) + assert_equal "cool, isn't it?", @logger.logged(:info).last + ensure + Rails::Subscriber.colorize_logging = true + end + + def test_event_is_sent_to_the_registered_class + Rails::Subscriber.add :my_subscriber, @subscriber + instrument "my_subscriber.some_event" + wait + assert_equal %w(my_subscriber.some_event), @logger.logged(:info) + end + + def test_does_not_send_the_event_if_it_doesnt_match_the_class + Rails::Subscriber.add :my_subscriber, @subscriber + instrument "my_subscriber.unknown_event" + wait + # If we get here, it means that NoMethodError was raised. + end + + def test_does_not_send_the_event_if_logger_is_nil + Rails.logger = nil + Rails::Subscriber.add :my_subscriber, @subscriber + instrument "my_subscriber.some_event" + wait + assert_equal [], @logger.logged(:info) + end +end
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