©2020 Wantedly, Inc. Wrap every method With just another line Meguro.rb#30 Jan 31, 2020 - Shimpei Otsubo 

©2020 Wantedly, Inc. Shimpei Otsubo @potsbo Developer Experience Squad, Wantedly, Inc. Kubernetes Dev Tools CI / CD AuthN / Z Productivity Dvorak 

©2020 Wantedly, Inc. AB ςετ͕೉͍͠໰୊ ςετ͕ͮ͠Β͘ͳΔ ࣗಈ΋खಈ΋ ޙΖଆͷϚΠΫϩαʔϏεͰߦ͏ͱ؅ཧෆೳ Ұ൪લͳΒ
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©2020 Wantedly, Inc. Thread.current resp header middleware ͲΜͳ஋Λ࢖͔ͬͨʁΛ
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©2020 Wantedly, Inc. class Experiment def self.enable?(name, target) # some consistent logic here end end Experiment.enable?(:show_new_button, current_user) # => true or false Wantedly ʹ͓͚Δ
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ʹར༻ͨ͠஋Λ٧ΊΔ class Experiment def self.enable?(name, target) # some consistent logic here end def self.wrapped_enable?(name, target) request_value = Thread.current[:request][name] return request_value unless request_value.nil? actual_value = enable?(name, target) Thread.current[:response][name] = actual_value end end ˞Thread.current
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©2020 Wantedly, Inc. Rename
ͯͦ͠ͷ··࢖͑ΔΑ͏ʹ͢Δ class Experiment def self.real_enable?(name, target) # some consistent logic here end def self.enable?(name, target) request_value = Thread.current[:request][name] return request_value unless request_value.nil? actual_value = real_enable?(name, target) Thread.current[:response][name] = actual_value end end 

©2020 Wantedly, Inc. ҰൠԽͯ͠ΈΔ class FeatureFlag def self.intercept(name) request_value = Thread.current[:request][name] return request_value unless request_value.nil? actual_value = yield Thread.current[:response][name] = actual_value end end class Experiment def self.real_enable?(name, target) # some consistent logic here end def self.enable?(name, target) FeatureFlag.intercept(name) do real_enable?(name, target) end end end ϒϩοΫͰғΈ͑͢͞Ε͹Ͳ͜Ͱ΋
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©2020 Wantedly, Inc. ଞͷػೳͷग़͠෼͚ʹ΋࢖͑Δ͸ͣ 

©2020 Wantedly, Inc. Helper
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method ͰػೳΛग़͠෼͚͍ͯ͠Δ৔ॴ͕͋Δ module I18nHelper # the new landing page currently supports only Japanese!! def show_new_landing_page? I18n.locale == :ja end end 

©2020 Wantedly, Inc. ϒϩοΫͰғΉ͚ͩͰ
XSBQ
Ͱ͖Δ class FeatureFlag def self.intercept(name) ... end end module I18nHelper # the new landing page currently supports only Japanese!! def show_new_landing_page? FeatureFlag.intercept(:show_new_landing_page?) do I18n.locale == :ja end end end 

©2020 Wantedly, Inc. ϒϩοΫͰғΉ͚ͩͰ
XSBQ
Ͱ͖Δ class FeatureFlag def self.intercept(name) ... end end module I18nHelper # the new landing page currently supports only Japanese!! def show_new_landing_page? FeatureFlag.intercept(:show_new_landing_page?) do I18n.locale == :ja end end end ຖճॻ͘ͷ͸ྲྀੴʹ໘౗ 

©2020 Wantedly, Inc. class FeatureFlag def self.intercept(name) ... end end module I18nHelper # the new landing page currently supports only Japanese!! def show_new_landing_page? FeatureFlag.intercept(:show_new_landing_page?) do I18n.locale == :ja end end end खಈͰίʔυΛ͍͡ΔͷͰ͸ͳ͘ 

©2020 Wantedly, Inc. class FeatureFlag def self.intercept(name) ... end end module I18nHelper include FeatureFlag def show_new_landing_page? I18n.locale == :ja end end *ODMVEF
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©2020 Wantedly, Inc. Ͱ͖ΔΑ͏ʹͨ͠ module FeatureFlag def self.included(base) base.class_eval do extend ClassMethods @_already_patched = [] @_patch_target = base end end module ClassMethods def intercept(name) ... end def method_added(name) if !@_already_patched.include?(name) && self == @_patch_target orig_method_name = "_#{base}_orig".to_sym @_already_patched << name @_already_patched << orig_method_name alias_method orig_method_name, name 

©2020 Wantedly, Inc. ॳظԽ module FeatureFlag def self.included(base) base.class_eval do extend ClassMethods @_already_patched = [] @_patch_target = base end end module ClassMethods def intercept(name) ... end def method_added(name) if !@_already_patched.include?(name) && self == @_patch_target orig_method_name = "_#{base}_orig".to_sym @_already_patched << name @_already_patched << orig_method_name alias_method orig_method_name, name Ͳͷ
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©2020 Wantedly, Inc. module ClassMethods def intercept(name) ... end def method_added(name) if !@_already_patched.include?(name) && self == @_patch_target orig_method_name = "_#{base}_orig".to_sym @_already_patched << name @_already_patched << orig_method_name alias_method orig_method_name, name private orig_method_name define_method(name) do |*args| intercept(name) do send(old_name, *args) end end end super end end end ͢Ͱʹ
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©2020 Wantedly, Inc. module ClassMethods def intercept(name) ... end def method_added(name) if !@_already_patched.include?(name) && self == @_patch_target orig_method_name = "_#{base}_orig".to_sym @_already_patched << name @_already_patched << orig_method_name alias_method orig_method_name, name private orig_method_name define_method(name) do |*args| intercept(name) do send(old_name, *args) end end end super end end end طଘ࣮૷ͷୀආ 

©2020 Wantedly, Inc. module ClassMethods def intercept(name) ... end def method_added(name) if !@_already_patched.include?(name) && self == @_patch_target orig_method_name = "_#{base}_orig".to_sym @_already_patched << name @_already_patched << orig_method_name alias_method orig_method_name, name private orig_method_name define_method(name) do |*args| intercept(name) do send(old_name, *args) end end end super end end end 8SBQ
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©2020 Wantedly, Inc. αʔόʔͷڍಈ͕ݟ͑Δม͑ΒΕΔͱָ *ODMVEF
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