Improve cache on route_key lookup.

3 files changed, 37 insertions, 6 deletions

diff --git a/actionpack/lib/action_dispatch/routing/polymorphic_routes.rb b/actionpack/lib/action_dispatch/routing/polymorphic_routes.rb
index e989a38d8b..013cf93dbc 100644
--- a/actionpack/lib/action_dispatch/routing/polymorphic_routes.rb
+++ b/actionpack/lib/action_dispatch/routing/polymorphic_routes.rb
@@ -165,7 +165,7 @@ module ActionDispatch
               if parent.is_a?(Symbol) || parent.is_a?(String)
                 parent
               else
-                ActiveModel::Naming.route_key(parent).singularize
+                ActiveModel::Naming.singular_route_key(parent)
               end
             end
           else
@@ -176,9 +176,11 @@ module ActionDispatch
           if record.is_a?(Symbol) || record.is_a?(String)
             route << record
           elsif record
-            route << ActiveModel::Naming.route_key(record)
-            route = [route.join("_").singularize] if inflection == :singular
-            route << "index" if ActiveModel::Naming.uncountable?(record) && inflection == :plural
+            if inflection == :singular
+              route << ActiveModel::Naming.singular_route_key(record)
+            else
+              route << ActiveModel::Naming.route_key(record)
+            end
           else
             raise ArgumentError, "Nil location provided. Can't build URI."
           end
diff --git a/activemodel/lib/active_model/naming.rb b/activemodel/lib/active_model/naming.rb
index 3caa61e41b..755e54efcd 100644
--- a/activemodel/lib/active_model/naming.rb
+++ b/activemodel/lib/active_model/naming.rb
@@ -5,7 +5,9 @@ require 'active_support/core_ext/module/deprecation'
 
 module ActiveModel
   class Name < String
-    attr_reader :singular, :plural, :element, :collection, :partial_path, :route_key, :param_key, :i18n_key
+    attr_reader :singular, :plural, :element, :collection, :partial_path,
+      :singular_route_key, :route_key, :param_key, :i18n_key
+
     alias_method :cache_key, :collection
 
     deprecate :partial_path => "ActiveModel::Name#partial_path is deprecated. Call #to_partial_path on model instances directly instead."
@@ -26,8 +28,12 @@ module ActiveModel
       @collection   = ActiveSupport::Inflector.tableize(self).freeze
       @partial_path = "#{@collection}/#{@element}".freeze
       @param_key    = (namespace ? _singularize(@unnamespaced) : @singular).freeze
-      @route_key    = (namespace ? ActiveSupport::Inflector.pluralize(@param_key) : @plural).freeze
       @i18n_key     = self.underscore.to_sym
+
+      @route_key          = (namespace ? ActiveSupport::Inflector.pluralize(@param_key) : @plural.dup)
+      @singular_route_key = ActiveSupport::Inflector.singularize(@route_key).freeze
+      @route_key << "_index" if @plural == @singular
+      @route_key.freeze
     end
 
     # Transform the model name into a more humane format, using I18n. By default,
@@ -117,10 +123,25 @@ module ActiveModel
     # namespaced models regarding whether it's inside isolated engine.
     #
     # For isolated engine:
+    # ActiveModel::Naming.route_key(Blog::Post) #=> post
+    #
+    # For shared engine:
+    # ActiveModel::Naming.route_key(Blog::Post) #=> blog_post
+    def self.singular_route_key(record_or_class)
+      model_name_from_record_or_class(record_or_class).singular_route_key
+    end
+
+    # Returns string to use while generating route names. It differs for
+    # namespaced models regarding whether it's inside isolated engine.
+    #
+    # For isolated engine:
     # ActiveModel::Naming.route_key(Blog::Post) #=> posts
     #
     # For shared engine:
     # ActiveModel::Naming.route_key(Blog::Post) #=> blog_posts
+    #
+    # The route key also considers if the noun is uncountable and, in
+    # such cases, automatically appends _index.
     def self.route_key(record_or_class)
       model_name_from_record_or_class(record_or_class).route_key
     end
diff --git a/activemodel/test/cases/naming_test.rb b/activemodel/test/cases/naming_test.rb
index b2976ab1fb..acda989eec 100644
--- a/activemodel/test/cases/naming_test.rb
+++ b/activemodel/test/cases/naming_test.rb
@@ -217,6 +217,7 @@ class NamingHelpersTest < Test::Unit::TestCase
     @singular = 'contact'
     @plural = 'contacts'
     @uncountable = Sheep
+    @singular_route_key = 'contact'
     @route_key = 'contacts'
     @param_key = 'contact'
   end
@@ -243,10 +244,12 @@ class NamingHelpersTest < Test::Unit::TestCase
 
   def test_route_key
     assert_equal @route_key, route_key(@record)
+    assert_equal @singular_route_key, singular_route_key(@record)
   end
 
   def test_route_key_for_class
     assert_equal @route_key, route_key(@klass)
+    assert_equal @singular_route_key, singular_route_key(@klass)
   end
 
   def test_param_key
@@ -262,6 +265,11 @@ class NamingHelpersTest < Test::Unit::TestCase
     assert !uncountable?(@klass), "Expected 'contact' to be countable"
   end
 
+  def test_uncountable_route_key
+    assert_equal "sheep", singular_route_key(@uncountable)
+    assert_equal "sheep_index", route_key(@uncountable)
+  end
+
   private
     def method_missing(method, *args)
       ActiveModel::Naming.send(method, *args)