getting better on joins

lib/arel/select_manager.rb

@@ -18,6 +18,16 @@ module Arel
       self
     end
 
+    def join relation, klass = Nodes::InnerJoin
+      case relation
+      when String, Nodes::SqlLiteral
+        raise if relation.blank?
+        from Nodes::StringJoin.new(@ctx.froms.pop, relation)
+      else
+        from klass.new(@ctx.froms.pop, relation, nil)
+      end
+    end
+
     def project *projections
       # FIXME: converting these to SQLLiterals is probably not good, but
       # rails tests require it.

lib/arel/visitors/dot.rb

@@ -28,6 +28,12 @@ module Arel
       end
 
       private
+      def visit_Arel_Nodes_TableAlias o
+        visit_edge o, "name"
+        visit_edge o, "relation"
+        visit_edge o, "columns"
+      end
+
       def visit_Arel_Nodes_Count o
         visit_edge o, "expressions"
         visit_edge o, "distinct"
@@ -37,6 +43,7 @@ module Arel
         visit_edge o, "left"
         visit_edge o, "right"
       end
+      alias :visit_Arel_Nodes_InnerJoin :visit_Arel_Nodes_StringJoin
 
       def visit_Arel_Nodes_InsertStatement o
         visit_edge o, "relation"

spec/arel/select_manager_spec.rb

@@ -63,7 +63,23 @@ module Arel
         predicate = left[:id].eq(right[:id])
         manager   = Arel::SelectManager.new Table.engine
 
+        manager.from left
         manager.join(right).on(predicate)
+        manager.to_sql.should be_like %{
+           SELECT FROM "users"
+             INNER JOIN "users" "users_2"
+               ON "users"."id" = "users_2"."id"
+        }
+      end
+
+      it 'takes a class' do
+        left      = Table.new :users
+        right     = left.alias
+        predicate = left[:id].eq(right[:id])
+        manager   = Arel::SelectManager.new Table.engine
+
+        manager.from left
+        manager.join(right, Nodes::OuterJoin).on(predicate)
         manager.to_sql.should be_like %{
            SELECT FROM "users"
              OUTER JOIN "users" "users_2"