4 files changed, 22 insertions, 10 deletions
diff --git a/activemodel/lib/active_model/errors.rb b/activemodel/lib/active_model/errors.rb
index 99f47f2cbe..fdca852c7a 100644
--- a/activemodel/lib/active_model/errors.rb
+++ b/activemodel/lib/active_model/errors.rb
@@ -165,7 +165,13 @@ module ActiveModel
 
     # Returns an ActiveSupport::OrderedHash that can be used as the JSON representation for this object.
     def as_json(options=nil)
-      self
+      to_hash
+    end
+
+    def to_hash
+      hash = ActiveSupport::OrderedHash.new
+      each { |k, v| (hash[k] ||= []) << v }
+      hash
     end
 
     # Adds +message+ to the error messages on +attribute+, which will be returned on a call to
diff --git a/activemodel/test/cases/errors_test.rb b/activemodel/test/cases/errors_test.rb
index 79b45bb298..27821c333b 100644
--- a/activemodel/test/cases/errors_test.rb
+++ b/activemodel/test/cases/errors_test.rb
@@ -62,4 +62,9 @@ class ErrorsTest < ActiveModel::TestCase
 
   end
 
+  test 'to_hash should return an ordered hash' do
+    person = Person.new
+    person.errors.add(:name, "can not be blank")
+    assert_instance_of ActiveSupport::OrderedHash, person.errors.to_hash
+  end
 end
diff --git a/activemodel/test/cases/serializeration/json_serialization_test.rb b/activemodel/test/cases/serializeration/json_serialization_test.rb
index 20d123ef0b..500a5c575f 100644
--- a/activemodel/test/cases/serializeration/json_serialization_test.rb
+++ b/activemodel/test/cases/serializeration/json_serialization_test.rb
@@ -6,6 +6,7 @@ require 'active_support/core_ext/object/instance_variables'
 class Contact
   extend ActiveModel::Naming
   include ActiveModel::Serializers::JSON
+  include ActiveModel::Validations
 
   def attributes
     instance_values
@@ -105,15 +106,15 @@ class JsonSerializationTest < ActiveModel::TestCase
   end
 
   test "should return OrderedHash for errors" do
-    car = Automobile.new
-
-    # run the validation
-    car.valid?
+    contact = Contact.new
+    contact.errors.add :name, "can't be blank"
+    contact.errors.add :name, "is too short (minimum is 2 characters)"
+    contact.errors.add :age, "must be 16 or over"
 
     hash = ActiveSupport::OrderedHash.new
-    hash[:make]  = "can't be blank"
-    hash[:model] = "is too short (minimum is 2 characters)"
-    assert_equal hash.to_json, car.errors.to_json
+    hash[:name] = ["can't be blank", "is too short (minimum is 2 characters)"]
+    hash[:age]  = ["must be 16 or over"]
+    assert_equal hash.to_json, contact.errors.to_json
   end
 
   test "serializable_hash should not modify options passed in argument" do
diff --git a/activemodel/test/cases/validations_test.rb b/activemodel/test/cases/validations_test.rb
index 4024002aaa..55b477dd10 100644
--- a/activemodel/test/cases/validations_test.rb
+++ b/activemodel/test/cases/validations_test.rb
@@ -174,8 +174,8 @@ class ValidationsTest < ActiveModel::TestCase
     assert_match %r{<error>Content can't be blank</error>}, xml
 
     hash = ActiveSupport::OrderedHash.new
-    hash[:title] = "can't be blank"
-    hash[:content] = "can't be blank"
+    hash[:title] = ["can't be blank"]
+    hash[:content] = ["can't be blank"]
     assert_equal t.errors.to_json, hash.to_json
   end