Added `none` query method to return zero records.

And added NullRelation class implementing the null object pattern for the `Relation` class.

1 files changed, 13 insertions, 0 deletions

diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index 5e19465253..0471d03f3b 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -215,6 +215,19 @@ class RelationTest < ActiveRecord::TestCase
     assert_equal [2, 4, 6, 8, 10], even_ids.sort
   end
 
+  def test_none
+    assert_no_queries do
+      assert_equal [], Developer.none
+      assert_equal [], Developer.scoped.none
+    end
+  end
+
+  def test_none_chainable
+    assert_no_queries do
+      assert_equal [], Developer.none.where(:name => 'David')
+    end
+  end
+
   def test_joins_with_nil_argument
     assert_nothing_raised { DependentFirm.joins(nil).first }
   end