Merge pull request #38659 from stevecrozz/inflection-locale-defaults-…

…and-fallbacks

Inflection support default_locale and fallbacks

activesupport/lib/active_support/i18n.rb

@@ -5,6 +5,7 @@
 require "active_support/core_ext/hash/slice"
 begin
   require "i18n"
+  require "i18n/backend/fallbacks"
 rescue LoadError => e
   $stderr.puts "The i18n gem is not available. Please add it to your Gemfile and run bundle install"
   raise e

activesupport/lib/active_support/inflector/inflections.rb

@@ -64,6 +64,13 @@ def self.instance(locale = :en)
         @__instance__[locale] ||= new
       end
 
+      def self.instance_or_fallback(locale)
+        I18n.fallbacks[locale].each do |k|
+          return @__instance__[k] if @__instance__.key?(k)
+        end
+        instance(locale)
+      end
+
       attr_reader :plurals, :singulars, :uncountables, :humans, :acronyms
 
       attr_reader :acronyms_camelize_regex, :acronyms_underscore_regex # :nodoc:
@@ -248,7 +255,7 @@ def inflections(locale = :en)
       if block_given?
         yield Inflections.instance(locale)
       else
-        Inflections.instance(locale)
+        Inflections.instance_or_fallback(locale)
       end
     end
   end

activesupport/test/inflector_test.rb

@@ -33,6 +33,12 @@ def test_pluralize_empty_string
     assert_equal "", ActiveSupport::Inflector.pluralize("")
   end
 
+  def test_pluralize_with_fallback
+    I18n.stub(:default_locale, :"en-GB") do
+      assert_equal "days", ActiveSupport::Inflector.pluralize("days")
+    end
+  end
+
   test "uncountability of ascii word" do
     word = "HTTP"
     ActiveSupport::Inflector.inflections do |inflect|