Calculations: return nil average instead of 0 when there are no rows to average. Closes #8298.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@6904 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 8 insertions, 0 deletions

diff --git a/activerecord/test/calculations_test.rb b/activerecord/test/calculations_test.rb
index e450c0a917..22ef78ce40 100644
--- a/activerecord/test/calculations_test.rb
+++ b/activerecord/test/calculations_test.rb
@@ -4,6 +4,10 @@ require 'fixtures/topic'
 
 Company.has_many :accounts
 
+class NumericData < ActiveRecord::Base
+  self.table_name = 'numeric_data'
+end
+
 class CalculationsTest < Test::Unit::TestCase
   fixtures :companies, :accounts, :topics
 
@@ -17,6 +21,10 @@ class CalculationsTest < Test::Unit::TestCase
     assert_in_delta 53.0, value, 0.001
   end
 
+  def test_should_return_nil_as_average
+    assert_nil NumericData.average(:bank_balance)
+  end
+
   def test_should_get_maximum_of_field
     assert_equal 60, Account.maximum(:credit_limit)
   end