refactoring join_sql to return nil if there are no sources

2 files changed, 12 insertions, 0 deletions

diff --git a/spec/select_manager_spec.rb b/spec/select_manager_spec.rb
index e5b65b4698..287657d0c1 100644
--- a/spec/select_manager_spec.rb
+++ b/spec/select_manager_spec.rb
@@ -299,6 +299,11 @@ module Arel
         manager.join_sql.should be_like %{ 'hello' }
         check manager.joins(manager).should == manager.join_sql
       end
+
+      it 'returns nil join sql' do
+        manager = Arel::SelectManager.new Table.engine
+        manager.join_sql.should be_nil
+      end
     end
 
     describe 'order_clauses' do
diff --git a/spec/table_spec.rb b/spec/table_spec.rb
index 15f2e024e0..d0ba46ae56 100644
--- a/spec/table_spec.rb
+++ b/spec/table_spec.rb
@@ -12,6 +12,13 @@ module Arel
       end
     end
 
+    describe 'select_manager' do
+      it 'should return an empty select manager' do
+        sm = @relation.select_manager
+        sm.to_sql.should be_like 'SELECT'
+      end
+    end
+
     describe 'having' do
       it 'adds a having clause' do
         mgr = @relation.having @relation[:id].eq(10)