Use a whitelist to delegate methods to array

1 files changed, 6 insertions, 18 deletions

diff --git a/activerecord/lib/active_record/relation/delegation.rb b/activerecord/lib/active_record/relation/delegation.rb
index 1e15bddcdf..af6be24351 100644
--- a/activerecord/lib/active_record/relation/delegation.rb
+++ b/activerecord/lib/active_record/relation/delegation.rb
@@ -36,7 +36,11 @@ module ActiveRecord
     # may vary depending on the klass of a relation, so we create a subclass of Relation
     # for each different klass, and the delegations are compiled into that subclass only.
 
-    delegate :to_xml, :to_yaml, :length, :collect, :map, :each, :all?, :include?, :to_ary, :to => :to_a
+    delegate :&, :+, :[], :all?, :collect, :detect, :each, :each_cons,
+             :each_with_index, :flat_map, :group_by, :include?, :length,
+             :map, :none?, :one?, :reverse, :sample, :second, :sort, :sort_by,
+             :to_ary, :to_set, :to_xml, :to_yaml, :to => :to_a
+
     delegate :table_name, :quoted_table_name, :primary_key, :quoted_primary_key,
              :connection, :columns_hash, :to => :klass
 
@@ -84,9 +88,6 @@ module ActiveRecord
         if @klass.respond_to?(method)
           self.class.delegate_to_scoped_klass(method)
           scoping { @klass.send(method, *args, &block) }
-        elsif array_delegable?(method)
-          self.class.delegate method, :to => :to_a
-          to_a.send(method, *args, &block)
         elsif arel.respond_to?(method)
           self.class.delegate method, :to => :arel
           arel.send(method, *args, &block)
@@ -109,28 +110,15 @@ module ActiveRecord
     end
 
     def respond_to?(method, include_private = false)
-      super || array_delegable?(method) ||
-        @klass.respond_to?(method, include_private) ||
+      super || @klass.respond_to?(method, include_private) ||
         arel.respond_to?(method, include_private)
     end
 
     protected
 
-    def array_delegable?(method)
-      defined = Array.method_defined?(method)
-      if defined && method.to_s.ends_with?('!')
-        ActiveSupport::Deprecation.warn(
-          "Association will no longer delegate #{method} to #to_a as of Rails 4.2. You instead must first call #to_a on the association to expose the array to be acted on."
-        )
-      end
-      defined
-    end
-
     def method_missing(method, *args, &block)
       if @klass.respond_to?(method)
         scoping { @klass.send(method, *args, &block) }
-      elsif array_delegable?(method)
-        to_a.send(method, *args, &block)
       elsif arel.respond_to?(method)
         arel.send(method, *args, &block)
       else