Add ParseTreeVisitor to RangeLookup

lib/liquid/range_lookup.rb

@@ -12,6 +12,8 @@ module Liquid
       end
     end
 
+    attr_reader :start_obj, :end_obj
+
     def initialize(start_obj, end_obj)
       @start_obj = start_obj
       @end_obj   = end_obj
@@ -35,5 +37,11 @@ module Liquid
         Utils.to_integer(input)
       end
     end
+
+    class ParseTreeVisitor < Liquid::ParseTreeVisitor
+      def children
+        [@node.start_obj, @node.end_obj]
+      end
+    end
   end
 end

test/unit/parse_tree_visitor_test.rb

@@ -159,6 +159,13 @@ class ParseTreeVisitorTest < Minitest::Test
     )
   end
 
+  def test_for_range
+    assert_equal(
+      ["test"],
+      visit(%({% for x in (1..test) %}{% endfor %}))
+    )
+  end
+
   def test_tablerow_in
     assert_equal(
       ["test"],