Merge pull request rails#55485 from byroot/uncountables-avoid-genivar

Optimize `#pluralize`

Author: byroot

activesupport/lib/active_support/inflector/inflections.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require "concurrent/map"
+require "active_support/core_ext/module/delegation"
 require "active_support/i18n"
 
 module ActiveSupport
@@ -29,44 +30,59 @@ module Inflector
     # before any of the rules that may already have been loaded.
     class Inflections
       @__instance__ = Concurrent::Map.new
+      @__en_instance__ = nil
+
+      class Uncountables # :nodoc:
+        include Enumerable
+
+        delegate :each, :pop, :empty?, :to_s, :==, :to_a, :to_ary, to: :@members
 
-      class Uncountables < Array
         def initialize
-          @regex_array = []
-          super
+          @members = []
+          @pattern = nil
         end
 
         def delete(entry)
-          super entry
-          @regex_array.delete(to_regex(entry))
+          @members.delete(entry)
+          @pattern = nil
+        end
+
+        def <<(word)
+          word = word.downcase
+          @members << word
+          @pattern = nil
+          self
         end
 
-        def <<(*word)
-          add(word)
+        def flatten
+          @members.dup
         end
 
         def add(words)
           words = words.flatten.map(&:downcase)
-          concat(words)
-          @regex_array += words.map { |word| to_regex(word) }
+          @members.concat(words)
+          @pattern = nil
           self
         end
 
         def uncountable?(str)
-          @regex_array.any? { |regex| regex.match? str }
-        end
-
-        private
-          def to_regex(string)
-            /\b#{::Regexp.escape(string)}\Z/i
+          if @pattern.nil?
+            members_pattern = Regexp.union(@members.map { |w| /#{Regexp.escape(w)}/i })
+            @pattern = /\b#{members_pattern}\Z/i
           end
+          @pattern.match?(str)
+        end
       end
 
       def self.instance(locale = :en)
+        return @__en_instance__ ||= new if locale == :en
+
         @__instance__[locale] ||= new
       end
 
       def self.instance_or_fallback(locale)
+        return @__en_instance__ ||= new if locale == :en
+
         I18n.fallbacks[locale].each do |k|
           return @__instance__[k] if @__instance__.key?(k)
         end

activesupport/test/inflector_test.rb

@@ -16,12 +16,16 @@ def setup
     # This helper is implemented by setting @__instance__ because in some tests
     # there are module functions that access ActiveSupport::Inflector.inflections,
     # so we need to replace the singleton itself.
-    @original_inflections = ActiveSupport::Inflector::Inflections.instance_variable_get(:@__instance__)[:en]
-    ActiveSupport::Inflector::Inflections.instance_variable_set(:@__instance__, en: @original_inflections.dup)
+    @original_inflections = ActiveSupport::Inflector::Inflections.instance_variable_get(:@__instance__)
+    @original_inflection_en = ActiveSupport::Inflector::Inflections.instance_variable_get(:@__en_instance__)
+
+    ActiveSupport::Inflector::Inflections.instance_variable_set(:@__instance__, {})
+    ActiveSupport::Inflector::Inflections.instance_variable_set(:@__en_instance__, @original_inflection_en.dup)
   end
 
   def teardown
-    ActiveSupport::Inflector::Inflections.instance_variable_set(:@__instance__, en: @original_inflections)
+    ActiveSupport::Inflector::Inflections.instance_variable_set(:@__instance__, @original_inflections)
+    ActiveSupport::Inflector::Inflections.instance_variable_set(:@__en_instance__, @original_inflection_en)
   end
 
   def test_pluralize_plurals
@@ -623,7 +627,7 @@ def test_clear_all_resets_camelize_and_underscore_regexes
 
         assert_equal [], inflect.singulars
         assert_equal [], inflect.plurals
-        assert_equal [], inflect.uncountables
+        assert_equal [], inflect.uncountables.to_a
 
         # restore all the inflections
         singulars.reverse_each { |singular| inflect.singular(*singular) }