Add nodes for boolean constants

This is useful for dynamically created predicates e.g:

expr1 = table.create_false
expr2 = table.create_false

expr1 = create_a_predicate() if some_condition
expr2 = create_another_predicate() if some_other_condition

table.where(expr1.and(expr2))

2 files changed, 26 insertions, 0 deletions

diff --git a/test/test_factory_methods.rb b/test/test_factory_methods.rb
index 50f77c3175..21671cd239 100644
--- a/test/test_factory_methods.rb
+++ b/test/test_factory_methods.rb
@@ -23,6 +23,16 @@ module Arel
         assert_equal :one, on.expr
       end
 
+      def test_create_true
+        true_node = @factory.create_true
+        assert_instance_of Nodes::True, true_node
+      end
+
+      def test_create_false
+        false_node = @factory.create_false
+        assert_instance_of Nodes::False, false_node
+      end
+
       def test_lower
         lower = @factory.lower :one
         assert_instance_of Nodes::NamedFunction, lower
diff --git a/test/visitors/test_to_sql.rb b/test/visitors/test_to_sql.rb
index b52722ddd6..3b58c71cd8 100644
--- a/test/visitors/test_to_sql.rb
+++ b/test/visitors/test_to_sql.rb
@@ -325,6 +325,22 @@ module Arel
         end
       end
 
+      describe 'Constants' do
+        it "should handle true" do
+          test = Table.new(:users).create_true
+          @visitor.accept(test).must_be_like %{
+            TRUE
+          }
+        end
+
+        it "should handle false" do
+          test = Table.new(:users).create_false
+          @visitor.accept(test).must_be_like %{
+            FALSE
+          }
+        end
+      end
+
       describe 'TableAlias' do
         it "should use the underlying table for checking columns" do
           test = Table.new(:users).alias('zomgusers')[:id].eq '3'