Add test to ensure preloading works as expected with "select" and "includes".

This didn't work in rails 3.1. See #2303 for more information and original pull request.

1 files changed, 13 insertions, 0 deletions

diff --git a/activerecord/test/cases/relations_test.rb b/activerecord/test/cases/relations_test.rb
index bc6cac0c6c..9d2229e733 100644
--- a/activerecord/test/cases/relations_test.rb
+++ b/activerecord/test/cases/relations_test.rb
@@ -1438,4 +1438,17 @@ class RelationTest < ActiveRecord::TestCase
     end
     assert_no_queries { relation.to_a }
   end
+
+  test 'group with select and includes' do
+    authors_count = Post.select('author_id, COUNT(author_id) AS num_posts').group('author_id').includes(:author).to_a
+
+    assert_no_queries do
+      result = authors_count.map do |post|
+        [post.num_posts, post.author.try(:name)]
+      end
+
+      expected = [[1, nil], [5, "David"], [3, "Mary"], [2, "Bob"]]
+      assert_equal expected, result
+    end
+  end
 end