ܧঝͱϝλϓϩάϥϛϯάຬࡌͳ ΞϓϦέʔγϣϯίʔυͰ΋ΞΫγϣϯͱ ϑΟϧλʹ೰·ͳ͍ͨΊͷGemΛ࡞ͬͨ࿩ 2020.10.03. Kaigi on Rails STAY HOME Edition @makicamel

w!NBLJDBNFM઒ݪສق wɹ w3VCZͱϏʔϧɹɹͱ͓ञ͕޷͖ ࣗݾ঺հ

͓खݩͷRails ΞϓϦʹ BQQMJDBUJPO@DPOUSPMMFSSC ͍ͭ͋͘Γ·͔͢ʁ ಥવͰ͕͢

˞೥݄೔ݱࡏ "/%1"% $ rails stats +----------------------+--------+--------+---------+---------+-----+-------+ | Name | Lines | LOC | Classes | Methods | M/C | LOC/M | +----------------------+--------+--------+---------+---------+-----+-------+ | Controllers | 66567 | 52928 | 1030 | 5473 | 5 | 7 | +----------------------+--------+--------+---------+---------+-----+-------+ $ find . -name application_controller.rb | wc -l 3 ׂ͕ ApplicationController # => 325

•֤֊૚͝ͱʹ application_controller.rb ͕͍Δ •֤ ApplicationController ͸ ਌֊૚ͷ ApplicationController Λܧঝ ͞Βʹ •ڞ௨ॲཧΛϞδϡʔϧԽ֤ͯ͠ॴͰ include •ϝλϓϩຬࡌ "/%1"% ˞೥݄೔ݱࡏ

Α͋͘Δޫܠ ɹ͜ͷϑΝΠϧΛमਖ਼͢Δͧ BXFTPNF@DPOUSPMMFSSC

ɹݖݶνΣοΫΛ֬ೝ͠Α͏ ᶃ ᶄ ᶅ ᶆ Α͋͘Δޫܠ BXFTPNF@DPOUSPMMFSSC •before_action ΛνΣοΫ

ɹ͑ͬ class Foo::Bar::Baz::ApplicationController < Foo::Bar::ApplicationController include Foo::Common::Bar::Baz::AwesomeController end Α͋͘Δޫܠ BXFTPNF@DPOUSPMMFSSC

BXFTPNF@DPOUSPMMFSSC ɹ͑ͬ͑ͬ class Foo::Bar::Baz::ApplicationController < Foo::Bar::ApplicationController include Foo::Common::Bar::Baz::AwesomeController end module Foo::Common::Bar::Baz::AwesomeController include Common::Bar::Baz::AwesomeController end Α͋͘Δޫܠ

Α͋͘Δޫܠ খ͞ͳमਖ਼΍ௐࠪͳͷʹ ܧঝؔ܎Λ֬ೝ͢Δ͚ͩͰർฐ͢Δ

ͱ͍͏Θ͚Ͱ

࡞ͬͨ NBLJDBNFMBDUJPO@USBDFS IUUQTHJUIVCDPNNBLJDBNFMBDUJPO@USBDFS

[2020-09-27T03:25:43.018298 #1] [“APPLIED",:set_turbolinks_location_header_from _session, “/usr/local/bundle/gems/turbolinks-… redirection.rb”, 43] [2020-09-27T03:25:43.019410 #1] ["APPLIED", :verify_authenticity_token, “/usr/ local/bundle/gems/actionpack-…/ request_forgery_protection.rb”, 211] [2020-09-27T03:25:43.021131 #1] ["APPLIED", :require_login, “/myapp/app/ controllers/awesome_controller.rb", 17] [2020-09-27T03:25:43.022063 #1] ["NO_APPLIED", :set_awesome, “/myapp/app/ controllers/awesome_controller.rb", 25] [2020-09-27T03:25:43.023716 #1] ["APPLIED", :with_readonly, “/myapp/app/ controllers/awesome_controller.rb", 21] [2020-09-27T03:25:43.025547 #1] ["ACTION", :index, “/myapp/app/controllers/ awesome_controller.rb", 7] [2020-09-27T03:25:43.026297 #1] ["APPLIED", :with_readonly, “/myapp/app/ controllers/awesome_controller.rb", 21] [2020-09-27T03:25:43.027203 #1] ["APPLIED", :store_location, “/myapp/app/ controllers/awesome_controller.rb", 27] [2020-09-27T03:25:43.030074 #1] ["APPLIED", :verify_same_origin_request, “/usr/ local/bundle/gems/actionpack-…/ request_forgery_protection.rb”, 240] class AwesomeController < ApplicationController before_action :require_login before_action :set_awesome, only: :show around_action :with_readonly after_action :store_location def index # ... end def show # ... end private def require_login # ... end # ... ˞ϩάͷҰ෦Λলུ͍ͯ͠·͢ɻྫ͸3&"%.&ʹ͋Γ·͢ɻ IUUQTHJUIVCDPNNBLJDBNFMBDUJPO@USBDFS ActionTracer ΞΫηε࣌ʹϑΟϧλΛॻ͖ग़͢

˞ϩάͷҰ෦Λলུ͍ͯ͠·͢ɻྫ͸3&"%.&ʹ͋Γ·͢ɻ IUUQTHJUIVCDPNNBLJDBNFMBDUJPO@USBDFS ActionTracer •ΞϓϦέʔγϣϯίʔυ͚ͩͰ͸ͳ͘ GemͷϑΟϧλ΋هࡌ [2020-09-27T03:25:43.018298 #1] [“APPLIED",:set_turbolinks_location_header_from _session, “/usr/local/bundle/gems/turbolinks-… redirection.rb”, 43] [2020-09-27T03:25:43.019410 #1] ["APPLIED", :verify_authenticity_token, “/usr/ local/bundle/gems/actionpack-…/ request_forgery_protection.rb”, 211] [2020-09-27T03:25:43.021131 #1] ["APPLIED", :require_login, “/myapp/app/ controllers/awesome_controller.rb", 17] [2020-09-27T03:25:43.022063 #1] ["NO_APPLIED", :set_awesome, “/myapp/app/ controllers/awesome_controller.rb", 25] [2020-09-27T03:25:43.023716 #1] ["APPLIED", :with_readonly, “/myapp/app/ controllers/awesome_controller.rb", 21] [2020-09-27T03:25:43.025547 #1] ["ACTION", :index, “/myapp/app/controllers/ awesome_controller.rb", 7] [2020-09-27T03:25:43.026297 #1] ["APPLIED", :with_readonly, “/myapp/app/ controllers/awesome_controller.rb", 21] [2020-09-27T03:25:43.027203 #1] ["APPLIED", :store_location, “/myapp/app/ controllers/awesome_controller.rb", 27] [2020-09-27T03:25:43.030074 #1] ["APPLIED", :verify_same_origin_request, “/usr/ local/bundle/gems/actionpack-…/ request_forgery_protection.rb”, 240] Turbolinks Rails ΞϓϦέʔγϣϯ ݺ͹ΕͨΞΫγϣϯ

˞ϩάͷҰ෦Λলུ͍ͯ͠·͢ɻྫ͸3&"%.&ʹ͋Γ·͢ɻ IUUQTHJUIVCDPNNBLJDBNFMBDUJPO@USBDFS ActionTracer •ϑΝΠϧύεɺߦ਺ [2020-09-27T03:25:43.018298 #1] [“APPLIED",:set_turbolinks_location_header_from _session, “/usr/local/bundle/gems/turbolinks-… redirection.rb”, 43] [2020-09-27T03:25:43.019410 #1] ["APPLIED", :verify_authenticity_token, “/usr/ local/bundle/gems/actionpack-…/ request_forgery_protection.rb”, 211] [2020-09-27T03:25:43.021131 #1] ["APPLIED", :require_login, “/myapp/app/ controllers/awesome_controller.rb", 17] [2020-09-27T03:25:43.022063 #1] ["NO_APPLIED", :set_awesome, “/myapp/app/ controllers/awesome_controller.rb", 25] [2020-09-27T03:25:43.023716 #1] ["APPLIED", :with_readonly, “/myapp/app/ controllers/awesome_controller.rb", 21] [2020-09-27T03:25:43.025547 #1] ["ACTION", :index, “/myapp/app/controllers/ awesome_controller.rb", 7] [2020-09-27T03:25:43.026297 #1] ["APPLIED", :with_readonly, “/myapp/app/ controllers/awesome_controller.rb", 21] [2020-09-27T03:25:43.027203 #1] ["APPLIED", :store_location, “/myapp/app/ controllers/awesome_controller.rb", 27] [2020-09-27T03:25:43.030074 #1] ["APPLIED", :verify_same_origin_request, “/usr/ local/bundle/gems/actionpack-…/ request_forgery_protection.rb”, 240]

˞ϩάͷҰ෦Λলུ͍ͯ͠·͢ɻྫ͸3&"%.&ʹ͋Γ·͢ɻ IUUQTHJUIVCDPNNBLJDBNFMBDUJPO@USBDFS ActionTracer •ͦͷϑΟϧλ͕ ࣮ࡍʹద༻͞Ε͔ͨ൱͔ •etc … [2020-09-27T03:25:43.018298 #1] [“APPLIED",:set_turbolinks_location_header_from _session, “/usr/local/bundle/gems/turbolinks-… redirection.rb”, 43] [2020-09-27T03:25:43.019410 #1] ["APPLIED", :verify_authenticity_token, “/usr/ local/bundle/gems/actionpack-…/ request_forgery_protection.rb”, 211] [2020-09-27T03:25:43.021131 #1] ["APPLIED", :require_login, “/myapp/app/ controllers/awesome_controller.rb", 17] [2020-09-27T03:25:43.022063 #1] ["NO_APPLIED", :set_awesome, “/myapp/app/ controllers/awesome_controller.rb", 25] [2020-09-27T03:25:43.023716 #1] ["APPLIED", :with_readonly, “/myapp/app/ controllers/awesome_controller.rb", 21] [2020-09-27T03:25:43.025547 #1] ["ACTION", :index, “/myapp/app/controllers/ awesome_controller.rb", 7] [2020-09-27T03:25:43.026297 #1] ["APPLIED", :with_readonly, “/myapp/app/ controllers/awesome_controller.rb", 21] [2020-09-27T03:25:43.027203 #1] ["APPLIED", :store_location, “/myapp/app/ controllers/awesome_controller.rb", 27] [2020-09-27T03:25:43.030074 #1] ["APPLIED", :verify_same_origin_request, “/usr/ local/bundle/gems/actionpack-…/ request_forgery_protection.rb”, 240]

ActionTracerͷͭ͘Γ͔ͨ

ActionTracer •ίʔυϕʔε͸খ͍͞ʢ200ߦະຬʣ

TracePoint DMBTT5SBDF1PJOUc3VCZϦϑΝϨϯεϚχϡΞϧ IUUQTEPDTSVCZMBOHPSHKBDMBTT5SBDF1PJOUIUNM

TracePoint •ॲཧΛొ࿥͓͖ͯ͠ɺ֤छΠϕϯτΛ͖͔͚ͬʹ࣮ߦͰ͖Δ •ΠϕϯτྫʢҰ෦ʣ •:line •:call •:return •:c_call •:c_return ࣜͷධՁ Ruby Ͱهड़͞Εͨϝιουͷݺͼग़͠ Ruby Ͱهड़͞Εͨϝιουݺͼग़͔͠ΒͷϦλʔϯ C Ͱهड़͞Εͨϝιουͷݺͼग़͠ C Ͱهड़͞Εͨϝιουݺͼग़͔͠ΒͷϦλʔϯ

TracePoint class AwesomeController < ApplicationController def index TracePoint.trace(:call) do |tp| p "#{tp.method_id}@#{tp.path}:#{tp.lineno}" end end # ...

No content

TracePoint •ॲཧΛొ࿥͓͖ͯ͠ɺ֤छΠϕϯτΛ͖͔͚ͬʹ࣮ߦͰ͖Δ •ΠϕϯτྫʢҰ෦ʣ •:line •:call •:return ࣜͷධՁ Ruby Ͱهड़͞Εͨϝιουͷݺͼग़͠ Ruby Ͱهड़͞Εͨϝιουݺͼग़͔͠ΒͷϦλʔϯ ΞϓϦέʔγϣϯίʔυ΋ Rails ͷίʔυ΋۠ผ͞Εͳ͍ ͍͍ײ͡ʹநग़͢ΔͱΑ͍ͷͰ͸

RailsͷίʔυΛ ಡΜͰΈΑ͏

before_action :login_required ͕࣮ߦ͞ΕΔ·Ͱ •Callback ͷొ࿥ •Callback ͷ࣮ߦ •Callback ͷొ࿥ •Callback ͷ࣮ߦ

ओͳొ৔ਓ෺ •ActiveSupport::Callbacks •AbstractController::Callbacks

ActiveSupport::Callbacks module ActiveSupport module Callbacks module Conditionals # :nodoc: module Filters class Callback #:nodoc:# class CallTemplate # :nodoc: class CallbackSequence # :nodoc: class CallbackChain #:nodoc:# module ClassMethods DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCDBBDUJWFTVQQPSUMJCBDUJWF@TVQQPSUDBMMCBDLTSC

AbstractController::Callbacks •AbstractController ͸ ApplicationController ͷ਌Ϋϥε ApplicationController < ActionController::Base < ActionController::Metal < AbstractController::Base

DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCFEDDDGBDUJPOQBDLMJCBCTUSBDU@DPOUSPMMFSDBMMCBDLTSC module AbstractController module Callbacks # ... included do define_callbacks( :process_action, terminator: ->(controller, result_lambda) { result_lambda.call if result_lambda.is_a?(Proc) controller.performed? }, skip_after_callbacks_if_terminated: true ) end # ... AbstractController

module ActiveSupport module Callbacks module Conditionals module Filters class Callback class CallTemplate class CallbackSequence class CallbackChain module ClassMethods DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCDBBDUJWFTVQQPSUMJCBDUJWF@TVQQPSUDBMMCBDLTSC def define_callbacks(*names) options = names.extract_options! names.each do |name| name = name.to_sym set_callbacks name, CallbackChain.new(name, options) module_eval <<-RUBY, __FILE__, __LINE__ + 1 def _run_#{name}_callbacks(&block) run_callbacks #{name.inspect}, &block end def self._#{name}_callbacks get_callbacks(#{name.inspect}) end def self._#{name}_callbacks=(value) set_callbacks(#{name.inspect}, value) end def _#{name}_callbacks __callbacks[#{name.inspect}] end RUBY end end ClassMethods

CallbackChain DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCDBBDUJWFTVQQPSUMJCBDUJWF@TVQQPSUDBMMCBDLTSC module ActiveSupport module Callbacks module Conditionals module Filters class Callback class CallTemplate class CallbackSequence class CallbackChain module ClassMethods class CallbackChain #:nodoc:# include Enumerable # ... def initialize(name, config) @name = name @config = { scope: [:kind], terminator: default_terminator }.merge!(config) @chain = [] @callbacks = nil @mutex = Mutex.new end # ... end # An Array with a compile method. CallbackΠϯελϯε͕ೖΔ ഑ྻϥΠΫͳΫϥε

DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCDBBDUJWFTVQQPSUMJCBDUJWF@TVQQPSUDBMMCBDLTSC def define_callbacks(*names) options = names.extract_options! names.each do |name| name = name.to_sym set_callbacks name, CallbackChain.new(name, options) module_eval <<-RUBY, __FILE__, __LINE__ + 1 def _run_#{name}_callbacks(&block) run_callbacks #{name.inspect}, &block end def self._#{name}_callbacks get_callbacks(#{name.inspect}) end def self._#{name}_callbacks=(value) set_callbacks(#{name.inspect}, value) end def _#{name}_callbacks __callbacks[#{name.inspect}] end RUBY end end module ActiveSupport module Callbacks module Conditionals module Filters class Callback class CallTemplate class CallbackSequence class CallbackChain module ClassMethods ClassMethods

DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCDBBDUJWFTVQQPSUMJCBDUJWF@TVQQPSUDBMMCBDLTSC def set_callbacks(name, callbacks) # :nodoc: self.__callbacks = __callbacks.merge(name.to_sym => callbacks) end module ActiveSupport module Callbacks module Conditionals module Filters class Callback class CallTemplate class CallbackSequence class CallbackChain module ClassMethods ClassMethods

DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCFEDDDGBDUJPOQBDLMJCBCTUSBDU@DPOUSPMMFSDBMMCBDLTSC module AbstractController module Callbacks module ClassMethods [:before, :after, :around].each do |callback| define_method "#{callback}_action" do |*names, &blk| _insert_callbacks(names, blk) do |name, options| set_callback(:process_action, callback, name, options) end end # ... end end end end AbstractController

DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCDBBDUJWFTVQQPSUMJCBDUJWF@TVQQPSUDBMMCBDLTSC def set_callback(name, *filter_list, &block) type, filters, options = normalize_callback_params(filter_list, block) # ... self_chain = get_callbacks name mapped = filters.map do |filter| Callback.build(self_chain, filter, type, options) end __update_callbacks(name) do |target, chain| options[:prepend] ? chain.prepend(*mapped) : chain.append(*mapped) target.set_callbacks name, chain end end module ActiveSupport module Callbacks module Conditionals module Filters class Callback class CallTemplate class CallbackSequence class CallbackChain module ClassMethods ClassMethods

DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCDBBDUJWFTVQQPSUMJCBDUJWF@TVQQPSUDBMMCBDLTSC class Callback #:nodoc:# # ... def initialize(name,filter,kind,options,chain_config) @chain_config = chain_config @name = name # => :process_action @kind = kind # => :before @filter = filter # => :login_required @key = compute_identifier filter # => :login_required @if = Array(options[:if]) # => :[#] @unless = Array(options[:unless]) # => [] end # ... module ActiveSupport module Callbacks module Conditionals module Filters class Callback class CallTemplate class CallbackSequence class CallbackChain module ClassMethods Callback ίʔϧόοΫຊମ before_action :login_required, except: :destroy ͷ৔߹

DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCDBBDUJWFTVQQPSUMJCBDUJWF@TVQQPSUDBMMCBDLTSC def set_callback(name, *filter_list, &block) type, filters, options = normalize_callback_params(filter_list, block) # ... self_chain = get_callbacks name mapped = filters.map do |filter| Callback.build(self_chain, filter, type, options) end __update_callbacks(name) do |target, chain| options[:prepend] ? chain.prepend(*mapped) : chain.append(*mapped) target.set_callbacks name, chain end end module ActiveSupport module Callbacks module Conditionals module Filters class Callback class CallTemplate class CallbackSequence class CallbackChain module ClassMethods ClassMethods

before_action :login_required ͕࣮ߦ͞ΕΔ·Ͱ •Callback ͷొ࿥ •Callback ͷ࣮ߦ •Callback ͷొ࿥ ɹɹɹɹɹɹɹɹ

DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCFEDDDGBDUJPOQBDLMJCBCTUSBDU@DPOUSPMMFSDBMMCBDLTSC AbstractController module AbstractController module Callbacks # ... def process_action(*args) run_callbacks(:process_action) do super end end end end

DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCDBBDUJWFTVQQPSUMJCBDUJWF@TVQQPSUDBMMCBDLTSC def run_callbacks(kind) callbacks = __callbacks[kind.to_sym] # ... next_sequence = callbacks.compile invoke_sequence = Proc.new do # ... end # Common case: no 'around' callbacks defined if next_sequence.final? # ... else invoke_sequence.call end # ... end module ActiveSupport module Callbacks module Conditionals module Filters class Callback class CallTemplate class CallbackSequence class CallbackChain module ClassMethods Callbacks

DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCDBBDUJWFTVQQPSUMJCBDUJWF@TVQQPSUDBMMCBDLTSC class CallbackChain #:nodoc:# # ... def compile @callbacks || @mutex.synchronize do final_sequence = CallbackSequence.new @callbacks ||= @chain.reverse.inject(final_sequence) do |callback_sequence, callback| callback.apply callback_sequence end end end # ... end # An Array with a compile method. module ActiveSupport module Callbacks module Conditionals module Filters class Callback class CallTemplate class CallbackSequence class CallbackChain module ClassMethods CallbackChain CallbackΠϯελϯε͕ೖΔ഑ྻΛ ࣋ͭΫϥε

DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCDBBDUJWFTVQQPSUMJCBDUJWF@TVQQPSUDBMMCBDLTSC class CallbackSequence # :nodoc: def initialize( nested = nil, call_template = nil, user_conditions = nil ) @nested = nested @call_template = call_template @user_conditions = user_conditions @before = [] @after = [] end # ... end module ActiveSupport module Callbacks module Conditionals module Filters class Callback class CallTemplate class CallbackSequence class CallbackChain module ClassMethods CallbackSequence ॱং௨ΓʹίʔϧόοΫΛอ؅͠ ࣮ߦ͍ͯ͘͠Ϋϥε

DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCDBBDUJWFTVQQPSUMJCBDUJWF@TVQQPSUDBMMCBDLTSC class CallbackChain #:nodoc:# # ... def compile @callbacks || @mutex.synchronize do final_sequence = CallbackSequence.new @callbacks ||= @chain.reverse.inject(final_sequence) do |callback_sequence, callback| callback.apply callback_sequence end end end # ... end # An Array with a compile method. module ActiveSupport module Callbacks module Conditionals module Filters class Callback class CallTemplate class CallbackSequence class CallbackChain module ClassMethods CallbackChain CallbackΠϯελϯε͕ೖΔ഑ྻΛ ࣋ͭΫϥε

DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCDBBDUJWFTVQQPSUMJCBDUJWF@TVQQPSUDBMMCBDLTSC def apply(callback_sequence) user_conditions = conditions_lambdas user_callback = CallTemplate.build(@filter, self) case kind when :before Filters::Before.build( callback_sequence, user_callback.make_lambda, user_conditions, chain_config, @filter ) when :after Filters::After.build( # before ͱಉ ) when :around callback_sequence.around( user_callback, user_conditions ) end end module ActiveSupport module Callbacks module Conditionals module Filters class Callback class CallTemplate class CallbackSequence class CallbackChain module ClassMethods Callback ίʔϧόοΫຊମ

DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCDBBDUJWFTVQQPSUMJCBDUJWF@TVQQPSUDBMMCBDLTSC class CallTemplate # :nodoc: # ... def self.build(filter, callback) case filter when Symbol new(nil, filter, [], nil) when String new( nil, :instance_exec, [:value], compile_lambda(filter) ) # ... end end # ... end module ActiveSupport module Callbacks module Conditionals module Filters class Callback class CallTemplate class CallbackSequence class CallbackChain module ClassMethods CallTemplate ίʔϧόοΫΛ࣮ߦ͢Δ ProcΛ࡞ΔΫϥε

DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCDBBDUJWFTVQQPSUMJCBDUJWF@TVQQPSUDBMMCBDLTSC def apply(callback_sequence) user_conditions = conditions_lambdas user_callback = CallTemplate.build(@filter, self) case kind when :before Filters::Before.build( callback_sequence, user_callback.make_lambda, user_conditions, chain_config, @filter ) when :after Filters::After.build( # before ͱಉ ) when :around callback_sequence.around( user_callback, user_conditions ) end end module ActiveSupport module Callbacks module Conditionals module Filters class Callback class CallTemplate class CallbackSequence class CallbackChain module ClassMethods Callback ίʔϧόοΫຊମ

DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCDBBDUJWFTVQQPSUMJCBDUJWF@TVQQPSUDBMMCBDLTSC module Filters # ... class Before def self.build( callback_sequence, user_callback, user_conditions, chain_config, filter ) halted_lambda = chain_config[:terminator] if user_conditions.any? # ... else halting( callback_sequence, user_callback, halted_lambda, filter ) end end module ActiveSupport module Callbacks module Conditionals module Filters class Callback class CallTemplate class CallbackSequence class CallbackChain module ClassMethods Filters if, unlessΛνΣοΫ͠ඞཁͳΒ ίʔϧόοΫΛhalt͢ΔΫϥε

DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCDBBDUJWFTVQQPSUMJCBDUJWF@TVQQPSUDBMMCBDLTSC def self.halting( callback_sequence, user_callback, halted_lambda, filter ) callback_sequence.before do |env| target = env.target value = env.value halted = env.halted unless halted result_lambda = -> { user_callback.call target, value } env.halted = halted_lambda.call(target, result_lambda) if env.halted target.send :halted_callback_hook, filter end end env end end module ActiveSupport module Callbacks module Conditionals module Filters class Callback class CallTemplate class CallbackSequence class CallbackChain module ClassMethods Filters if, unlessΛνΣοΫ͠ඞཁͳΒ ίʔϧόοΫΛhalt͢ΔΫϥε

DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCDBBDUJWFTVQQPSUMJCBDUJWF@TVQQPSUDBMMCBDLTSC module ActiveSupport module Callbacks module Conditionals module Filters class Callback class CallTemplate class CallbackSequence class CallbackChain module ClassMethods def self.halting( callback_sequence, user_callback, halted_lambda, filter ) callback_sequence.before do |env| target = env.target value = env.value halted = env.halted unless halted result_lambda = -> { user_callback.call target, value } env.halted = halted_lambda.call(target, result_lambda) if env.halted target.send :halted_callback_hook, filter end end env end end def apply(callback_sequence) # ... user_callback = CallTemplate.build # ... case kind when :before Filters::Before.build( callback_sequence, user_callback.make_lambda, user_conditions, chain_config, @filter ) Filters

DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCDBBDUJWFTVQQPSUMJCBDUJWF@TVQQPSUDBMMCBDLTSC def make_lambda lambda do |target, value, &block| target, block, method, *arguments = expand(target, value, block) target.send(method, *arguments, &block) end end module ActiveSupport module Callbacks module Conditionals module Filters class Callback class CallTemplate class CallbackSequence class CallbackChain module ClassMethods CallTemplate ίʔϧόοΫΛ࣮ߦ͢Δ ProcΛ࡞ΔΫϥε

DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCDBBDUJWFTVQQPSUMJCBDUJWF@TVQQPSUDBMMCBDLTSC def expand(target, value, block) result = @arguments.map { |arg| case arg when :value; value when :target; target when :block; block || raise(ArgumentError) end } result.unshift @method_name result.unshift @override_block || block result.unshift @override_target || target # target, block, method, *arguments = result # target.send(method, *arguments, &block) result end ϦΫΤετΛड͚ͨίϯτϩʔϥ before_actionͰొ࿥ͨ͠
 Πϯελϯεϝιου module ActiveSupport module Callbacks module Conditionals module Filters class Callback class CallTemplate class CallbackSequence class CallbackChain module ClassMethods CallTemplate ίʔϧόοΫΛ࣮ߦ͢Δ ProcΛ࡞ΔΫϥε AwesomeController.new.send(:login_required) ͱҰॹʂʂ

☕

No content

TracePoint ͍Βͳ͘ͳ͍ʁ

औΕͨ class AwesomeController < ApplicationController def index p self.__callbacks[:process_action].class # => ActiveSupport::Callbacks::CallbackChain p self.__callbacks[:process_action].send(:chain).first # => #[:kind], # :terminator=>#, # :skip_after_callbacks_if_terminated=>true}, # @filter=:require_login, # @if=[#], # @key=:require_login, # @kind=:before, # @name=:process_action, # @unless=[]> end end

5JNFUBCMFc,BJHJPO3BJMT IUUQTLBJHJPOSBJMTPSHUJNFUBCMF Ϡό͍

ͱΓ͋͑ͣ։ൃΛਐΊΔ ࢖Θͳ͔ͬͨΒँΖ͏

AbstractController::Callbacks module AbstractController module Callbacks # ... def process_action(*args) run_callbacks(:process_action) do super end end end end ϞϯΩʔύονͰ͜ͷݺͼग़͠ޙʹ ͍͍ײ͡ʹॻ͖ग़ͯ͋͛ͨ͠ΒΑͦ͞͏

ϞϯΩʔύον module ActionTracer module MonkeyPatches module AbstractController module Callbacks def process_action(*args) ActionTracer.log(self) do super end end end end end end AbstractController::Callbacks#process_action ΛΦʔόʔϥΠυ

͍͍ײ͡ʹॻ͖ग़͢ module ActionTracer class << self def log(controller) result = yield Filters.build(controller).print result end end end

͍͍ײ͡ʹॻ͖ग़͢ class ActionTracer::Filters def self.build(controller) # ... raw_filters = controller.__callbacks[:process_action].send(:chain) raw_filters.group_by(&:kind).each do |kind, filter| filters[kind] = filter.map(&:raw_filter).map do |f| Filter.new(f, method: f.is_a?(Symbol) ? controller.method(f) : f) end end # ... end def print (@before + @around).map(&:to_a).each do |filter| ActionTracer.logger.info filter end # ... end end

I, [2020-09-23T01:51:32.772847 #2] INFO -- : [:verify_authenticity_token, “/usr/local/bundle/gems/actionpack-5.1.7/lib/action_controller/ metal/request_forgery_protection.rb", 211] ͍͍ײ͡ʹॻ͖ग़͢ class ActionTracer::Filter # ... def to_a [@filter, *@method.source_location] end end Ͱ͖ͨ

खݩͷ͓࢓ࣄͰ࢖ͬͯΈΔ •࠷ߴ •ࠓ·ͰͻͱͭͣͭܧঝݩΛͨͲͬͯ֬ೝ͍ͯͨ͠ͷ͸ͳΜͩͬͨͷ͔ •RSpec Ͱ࢖ͬͯ΋ศརͱ͔ɺϢʔεέʔεΛࢥ͍ͭ͘ •ཁ๬΋ग़ͯ͘Δ •PR ʹهࡌ͢ΔͷʹϑΟϧλ໊͚ͩ map ͓ͯ͠खܰʹίϐʔ͍ͨ͠ •࣮ࡍʹϑΟϧλ͕ద༻͞Ε͔ͨ΋஌Γ͍ͨ

ͦ͜Ͱ TracePoint Α͔ͬͨ

ActiveSupport::Callbacks DBMMCBDLTSCcSBJMTSBJMT IUUQTHJUIVCDPNSBJMTSBJMTCMPCDBBDUJWFTVQQPSUMJCBDUJWF@TVQQPSUDBMMCBDLTSC def expand(target, value, block) result = @arguments.map { |arg| case arg when :value; value when :target; target when :block; block || raise(ArgumentError) end } result.unshift @method_name result.unshift @override_block || block result.unshift @override_target || target # target, block, method, *arguments = result # target.send(method, *arguments, &block) result end expand ͕ݺ͹ΕΔͷ͸ ࣮ࡍʹ࣮ߦ͞ΕΔίʔϧόοΫ͚ͩ

module ActionTracer def self.filter_collector @filter_collector ||= TracePoint.new(:return) do |tp| # NOTE: ActiveSupport::Callbacks::CallTemplate is a private class if tp.method_id == :expand && tp.defined_class == ActiveSupport::Callbacks::CallTemplate if tp.return_value&.first.is_a? ActionController::Base case tp.return_value[2] # ... when Symbol # filter is a method applied_filters << tp.return_value[2] end end end end end def self.applied_filters @applied_filters ||= [] end end BDUJPO@USBDFSSCcNBLJDBNFMBDUJPO@USBDFS IUUQTHJUIVCDPNNBLJDBNFMBDUJPO@USBDFSCMPCGMJCBDUJPO@USBDFSBDUJPO@USBDFSSC

ग़ྗͰ͖ͨ I, [2020-09-27T03:25:43.018298 #1] INFO -- : [“APPLIED",:set_turbolinks_location_header_from _session, “/usr/local/bundle/gems/turbolinks-redirection.rb”, 43] I, [2020-09-27T03:25:43.019410 #1] INFO -- : ["APPLIED", :verify_authenticity_token, “/usr/local/bundle/gems/actionpack-…/request_forgery_protection.rb”, 211] I, [2020-09-27T03:25:43.021131 #1] INFO -- : ["APPLIED", :require_login, “/myapp/app/controllers/awesome_controller.rb", 17] I, [2020-09-27T03:25:43.022063 #1] INFO -- : ["NO_APPLIED", :set_awesome, “/myapp/app/controllers/awesome_controller.rb", 25] I, [2020-09-27T03:25:43.023716 #1] INFO -- : ["APPLIED", :with_readonly, “/myapp/app/controllers/awesome_controller.rb", 21] I, [2020-09-27T03:25:43.025547 #1] INFO -- : ["ACTION", :index, “/myapp/app/controllers/awesome_controller.rb", 7] I, [2020-09-27T03:25:43.026297 #1] INFO -- : ["APPLIED", :with_readonly, “/myapp/app/controllers/awesome_controller.rb", 21] I, [2020-09-27T03:25:43.027203 #1] INFO -- : ["APPLIED", :store_location, “/myapp/app/controllers/awesome_controller.rb", 27] I, [2020-09-27T03:25:43.030074 #1] INFO -- : ["APPLIED", :verify_same_origin_request, “/usr/local/bundle/gems/actionpack-…/request_forgery_protection.rb”, 240]

;ΓฦΓ

;ΓฦΓ •Gem Λ࡞Δͷʹඞཁͳ෺ͬͯԿͩΖ͏ •ٕज़ͱ஌ࣝʁ •ΞΠσΟΞʁ

ٕज़ͱ஌ࣝʁ •ActionTracer Ͱ΍ͬͨ͜ͱ͸΄΅ Rails ͷίʔυϦʔσΟϯά •ٕज़ྗ͕͋Δʹӽͨ͜͠ͱ͸ͳ͍ʢͦΕ͸ͦ͏ʣ •ٕज़͕͋Δ͔Β Gem Λ࡞ΔͷͰ͸ͳ͘࡞Δ͜ͱͰྗ͕͍͍ͭͯ͘ •ඞཁ͸ൃ໌ͱ੒௕ͷ฼

ྫ͑͹ •TracePoint ΛԿ΋ߟ͑ͣʹ࢖͏ͱॏ͘ͳΔ •શͯͷΠϕϯτͰൃՐ͢ΔͷͰ •࣮ߦ࣌ʹΦϓγϣϯΛ౉ͯ͠࢖͍͍͚ͨ࣌ͩ࢖͍͍ͨ •bundle exec rails server -actiontracer on Έ͍ͨͳײ͡ʁ

೉ͦ͠͏ •·ͨϞϯΩʔύον…ʁ •࠷࣮ۙߦ࣌Φϓγϣϯ౉ͨ͠ྫΛݟͨͧ LLVCVOSTQFDPQFOBQJ IUUQTHJUIVCDPNLLVCVOSTQFDPQFOBQJ

rspec-openapi •RSpec ͷϦΫΤετ spec ͔Β OpenAPI ͷεΩʔϚΛ࡞੒͢Δ Gem •͜Εͩʂ LLVCVOSTQFDPQFOBQJ IUUQTHJUIVCDPNLLVCVOSTQFDPQFOBQJ

rspec-openapi PQFOBQJSCcLLVCVOSTQFDPQFOBQJ IUUQTHJUIVCDPNLLVCVOSTQFDPQFOBQJCMPCGEEMJCSTQFDPQFOBQJSC require 'rspec/openapi/version' require 'rspec/openapi/hooks' if ENV['OPENAPI'] module RSpec::OpenAPI # ... end

ActionTracer BDUJPO@USBDFSSCcNBLJDBNFMBDUJPO@USBDFS IUUQTHJUIVCDPNNBLJDBNFMBDUJPO@USBDFSCMPCCGEBMJCBDUJPO@USBDFSSC require "action_tracer/version" require "action_tracer/railtie" if ENV["ACTION_TRACER"] require "action_tracer/filters" require "action_tracer/logger" require "action_tracer/action_tracer" ੈͷதʹ͸ແ਺ͷ͓खຊίʔυ͕͋Δ

ͱʹ͔͘ॻ͘ •౴͑ͷͳ͍ঢ়ଶͰॻ͖࢝ΊΔͱ͏·͘ॻ͚ͳ͍ •Ԛ͍ίʔυΛॻ͜͏ͱ͢ΔͱϞϠοͱ͢Δ •ʮ·ͣ͸Ԛͯ͘΋ॻ͍͔ͯΒ͖Ε͍ʹ͢Δʯͱࣗ෼ʹݴ͍ฉ͔ͤΔ •ॻ͘ͱ೴ΈͦͷϝϞϦ͕ۭ͘ͷͰࢥߟ͕ਐΉ •git ͷྺ࢙͸վมՄೳ

Πϯλʔωοτʹฉ͘ •ʮgem ࡞Γํʯ ͸͡Ίͯͷࣗ࡞HFNʮ)FMMP 5BNBʯΛग़ྗͯ͠ΈΔ!DPF@c2JJUB IUUQTRJJUBDPNDPF@JUFNTFBGFGBCF

ΞΠσΟΞʁ ;0;0ςΫϊϩδʔζͷٕज़ސ໰؛઒ࢯɺদాࢯɺ.BU[ࢯʹฉ͘ΤϯδχΞਓੜɻʙͱʹ͔͘ॻ͘ɺॻ͘͜ͱΛָ͠Ήʙ IUUQTUFDICMPH[P[PDPNFOUSZ@JOUFSWJFX ݱ৔ͷࠓ͋Δ՝୊Λ ͖ͪΜͱΦʔϓϯͳίʔυͰղܾ͢Δ

ɹ૸ͬͯΔϑΟϧλ͕Θ͔Βͳ͍ͷͭΒ͍Ͱ͢Ͷ ɹͭΒ͍Ͱ͢Ͷ… ɹҰཡͰݟ͍ͨͰ͢Ͷ ɹͦΕͩʂʂ ʮݱ৔ͷࠓ͋Δ՝୊ʯ

•ΞϓϦ͕஗͍ •CI ͕஗͍ •ϦϦʔε࡞ۀ͕஗͍ •։ൃ଎౓͕஗͍ •ίʔυ͕ಡΈʹ͍͘ •ίʔυ͕Ԛ͍ •etc etc… ʮݱ৔ͷࠓ͋Δ՝୊ʯ ෆద੾ͳΤϥʔϋϯυϦϯά ଐਓԽ͍ͯ͠ΔΤϥʔ؂ࢹ ແବͳSQLͷൃߦ ίʔσΟϯάϧʔϧ͕গͳ͍ ແடংͳϝλϓϩ େྔͷσουίʔυ ࢖ΘΕ͍ͯͳ͍ΞΫγϣϯ େྔͷApplicationController ਖ਼نԽ͞Ε͍ͯͳ͍ςʔϒϧ ൿ఻ͷλϨscope ௒ઈFatModel γεςϜεϖοΫ͕গͳ͍ ແବͳςετσʔλͷ࡞੒ ΦϨΦϨϙϦϞʔϑΟοΫςʔϒϧ ߦ͖ա͗ͨڞ௨Խ

•ͲΜͳݱ৔ʹ΋՝୊͸͋Δ •՝୊ͷΞϓϩʔνํ๏͸৭ʑ •ࠜຊղܾɾԠٸख౰ •ͭΒΈΛݴޠԽ͢ΔͱରԠํ๏͕ੜ·ΕΔͷͰޱʹग़͢ ʮݱ৔ͷࠓ͋Δ՝୊ʯ

ετϨεʹහײʹͳΔ •ϓϩάϥϚͷࡾେඒಙ •ଵଦɾ୹ؾɾၗຫ OE4UBUFPGUIF0OJPOc-BSSZ8BMM IUUQTXXXQFSMDPNQVCTIPXPOJPOIUNM ఘΊͣʹେਓʹͳΒͣʹΧοͱͳͬͯ΍Δ

࡞Δͷ͸ָ͍͠ •ϥΠϒϥϦͷίʔυΛಡΉػձ͕૿͑Δ •ʮ͜ͷؒݟͨʂʯ͕૿͑Δ •ͦͷύλʔϯ͕ͦͷύλʔϯͰ͋Δཧ༝Λߟ͑Δͷ΋ָ͍͠ •Α͍ύλʔϯ͕ࣗ෼ͷதʹ஝ੵ͞Ε͍͖ͯͦ͏

࡞Δͷ͸ָ͍͠ •ࣗ෼͕Ұ൪ͷϢʔβʔͰ͋Δಓ۩ •࢖͏ͱ࠷ߴʹؾ͍͍࣋ͪ •ਓ͕࢖ͬͯتΜͰ͘ΕΔͱخ͍͠

·ͱΊ •࡞Δͷ͸ָ͍͠ •ٕज़ྗ͸ޙ͔Β͍ͭͯ͘Δ •՝୊͸൒ܘ 5m ͷ਎ͷճΓʹ͖ͬͱ͋Δ

͝ਗ਼ௌ͋Γ͕ͱ͏͍͟͝·ͨ͠