Added Enumerable#sum for calculating a sum from the elements [DHH]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@4489 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 8 insertions, 1 deletions

diff --git a/activesupport/test/core_ext/enumerable_test.rb b/activesupport/test/core_ext/enumerable_test.rb
index df14200e42..882111cd79 100644
--- a/activesupport/test/core_ext/enumerable_test.rb
+++ b/activesupport/test/core_ext/enumerable_test.rb
@@ -1,8 +1,9 @@
 require 'test/unit'
 require File.dirname(__FILE__) + '/../../lib/active_support/core_ext/enumerable'
 
+Payment = Struct.new(:price)
+
 class EnumerableTests < Test::Unit::TestCase
-  
   def test_group_by
     names = %w(marcel sam david jeremy)
     klass = Class.new
@@ -17,4 +18,10 @@ class EnumerableTests < Test::Unit::TestCase
       assert group.all? {|person| person.name == name}
     end
   end
+  
+  def test_sums
+    payments = [ Payment.new(5), Payment.new(15), Payment.new(10) ]
+    assert_equal 30, payments.sum(&:price)
+    assert_equal 60, payments.sum { |p| p.price * 2 }
+  end
 end