Add equality to ALL THE THINGS (that matter)

People are often trying to use ARel nodes inside ActiveRecord, and when
they do so, lots of things can break, because ActiveRecord relies on
Array#uniq and sometimes hash key equality to handle values that end up
in wheres, havings, etc. By implementing equality for all the nodes, we
should hopefully be able to prevent any nodes (even nodes containing
other nodes) from failing an equality check they should otherwise pass,
and alleviate many of these errors.

Fixes #130

1 files changed, 10 insertions, 0 deletions

diff --git a/test/nodes/test_infix_operation.rb b/test/nodes/test_infix_operation.rb
index 3d2eb0d9c6..b7b6b02d0f 100644
--- a/test/nodes/test_infix_operation.rb
+++ b/test/nodes/test_infix_operation.rb
@@ -25,6 +25,16 @@ module Arel
         assert_equal operation, ordering.expr
         assert ordering.descending?
       end
+
+      def test_equality_with_same_ivars
+        array = [InfixOperation.new(:+, 1, 2), InfixOperation.new(:+, 1, 2)]
+        assert_equal 1, array.uniq.size
+      end
+
+      def test_inequality_with_different_ivars
+        array = [InfixOperation.new(:+, 1, 2), InfixOperation.new(:+, 1, 3)]
+        assert_equal 2, array.uniq.size
+      end
     end
   end
 end