Merge remote branch 'sven/in-subquery' into subquery

* sven/in-subquery:
  implementation for passing a subquery to #in and #not_in
  tests for passing a subquery to #in and #not_in

lib/arel/predications.rb

@@ -31,7 +31,7 @@ module Arel
     def in other
       case other
       when Arel::SelectManager
-        Nodes::In.new self, other.to_a.map { |x| x.id }
+        Arel::Nodes::In.new(self, other)
       when Range
         if other.exclude_end?
           left  = Nodes::GreaterThanOrEqual.new(self, other.begin)
@@ -56,7 +56,7 @@ module Arel
     def not_in other
       case other
       when Arel::SelectManager
-        Nodes::NotIn.new self, other.to_a.map { |x| x.id }
+        Arel::Nodes::NotIn.new(self, other)
       when Range
         if other.exclude_end?
           left  = Nodes::LessThan.new(self, other.begin)

lib/arel/visitors/to_sql.rb

@@ -101,6 +101,10 @@ module Arel
         }.join ', '})"
       end
 
+      def visit_Arel_SelectManager o
+        o.to_sql
+      end
+
       def visit_Arel_Nodes_SelectStatement o
         [
           o.cores.map { |x| visit_Arel_Nodes_SelectCore x }.join,
@@ -233,17 +237,11 @@ module Arel
       end
 
       def visit_Arel_Nodes_In o
-        right = o.right
-        "#{visit o.left} IN (#{
-          right.empty? ? 'NULL' : right.map { |x| visit x }.join(', ')
-        })"
+      "#{visit o.left} IN (#{visit o.right})"
       end
 
       def visit_Arel_Nodes_NotIn o
-        right = o.right
-        "#{visit o.left} NOT IN (#{
-          right.empty? ? 'NULL' : right.map { |x| visit x }.join(', ')
-        })"
+      "#{visit o.left} NOT IN (#{visit o.right})"
       end
 
       def visit_Arel_Nodes_And o
@@ -320,6 +318,10 @@ module Arel
       alias :visit_ActiveSupport_StringInquirer :visit_String
       alias :visit_Class :visit_String
 
+      def visit_Array o
+        o.empty? ? 'NULL' : o.map { |x| visit x }.join(', ')
+      end
+
       def quote value, column = nil
         @connection.quote value, column
       end

test/visitors/test_to_sql.rb

@@ -143,6 +143,15 @@ module Arel
           }
         end
 
+        it 'can handle subqueries' do
+          table = Table.new(:users)
+          subquery = table.project(:id).where(table[:name].eq('Aaron'))
+          node = @attr.in subquery
+          @visitor.accept(node).must_be_like %{
+            "users"."id" IN (SELECT id FROM "users" WHERE "users"."name" = 'Aaron')
+          }
+        end
+
         it 'uses the same column for escaping values' do
         @attr = Table.new(:users)[:name]
           visitor = Class.new(ToSql) do
@@ -191,6 +200,15 @@ module Arel
           }
         end
 
+        it 'can handle subqueries' do
+          table = Table.new(:users)
+          subquery = table.project(:id).where(table[:name].eq('Aaron'))
+          node = @attr.not_in subquery
+          @visitor.accept(node).must_be_like %{
+            "users"."id" NOT IN (SELECT id FROM "users" WHERE "users"."name" = 'Aaron')
+          }
+        end
+
         it 'uses the same column for escaping values' do
         @attr = Table.new(:users)[:name]
           visitor = Class.new(ToSql) do