new assertion: assert_blank

Signed-off-by: Xavier Noria <fxn@hashref.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/activesupport/lib/active_support/testing/assertions.rb b/activesupport/lib/active_support/testing/assertions.rb
index c529b92240..30a22fcc0e 100644
--- a/activesupport/lib/active_support/testing/assertions.rb
+++ b/activesupport/lib/active_support/testing/assertions.rb
@@ -62,6 +62,13 @@ module ActiveSupport
       def assert_no_difference(expression, message = nil, &block)
         assert_difference expression, 0, message, &block
       end
+      
+      # Test if an expression is blank. Passes if object.blank? is true.
+      #
+      #   assert_blank [] # => true
+      def assert_blank(object)
+        assert object.blank?, "#{object.inspect} is not blank"
+      end
     end
   end
 end