WIP comments

lib/arel/nodes/node.rb

@@ -3,6 +3,8 @@ module Nodes
     ###
     # Abstract base class for all AST nodes
     class Node
+      attr_accessor :comment
+
       include Arel::FactoryMethods
       include Enumerable
 

lib/arel/select_manager.rb

@@ -254,6 +254,12 @@ def joins manager
       manager.join_sql
     end
 
+    def comment comment
+      @ast.comment ||= []
+      @ast.comment << comment
+      self
+    end
+
     class Row < Struct.new(:data) # :nodoc:
       def id
         data['id']

lib/arel/tree_manager.rb

@@ -18,7 +18,9 @@ def visitor
     end
 
     def to_sql
-      visitor.accept @ast
+      sql = visitor.accept ast
+      sql << " /* #{ast.comment.join(" ")} */" if ast.comment
+      sql
     end
 
     def initialize_copy other

test/test_select_manager.rb

@@ -1155,5 +1155,19 @@ def test_join_sources
         manager.ast.cores.last.set_quantifier.must_equal nil
       end
     end
+
+    describe 'comment' do
+      it 'makes sql' do
+        manager = Arel::SelectManager.new Table.engine
+        manager.comment("XXX")
+        manager.to_sql.must_be_like 'SELECT /* XXX */'
+      end
+
+      it 'makes sql chains' do
+        manager = Arel::SelectManager.new Table.engine
+        manager.comment("XXX").comment("YYY")
+        manager.to_sql.must_be_like 'SELECT /* XXX YYY */'
+      end
+    end
   end
 end