Support for multiple selects added

[#4841 state:committed]

activerecord/lib/active_record/relation/query_methods.rb

@@ -213,13 +213,16 @@ def build_joins(relation, joins)
     def build_select(arel, selects)
       if selects.present?
         @implicit_readonly = false
-        selects.each do |s|
-          arel = arel.project(s) if s.present?
+        # TODO: fix this ugly hack, we should refactor the callers to get an ARel compatible array.
+        # Before this change we were passing to ARel the last element only, and ARel is capable of handling an array
+        if selects.all? { |s| s.is_a?(String) || !s.is_a?(Arel::Expression) } && !(selects.last =~ /^COUNT\(/)
+          arel.project(*selects)
+        else
+          arel.project(selects.last)
         end
       else
-        arel = arel.project(@klass.quoted_table_name + '.*')
+        arel.project(@klass.quoted_table_name + '.*')
       end
-      arel
     end
 
     def apply_modules(modules)

activerecord/test/cases/method_scoping_test.rb

@@ -77,11 +77,13 @@ def test_scoped_find_select
     end
   end
 
-  def test_options_select_replaces_scope_select
-    Developer.send(:with_scope, :find => { :select => "id, name" }) do
+  def test_scope_select_concatenates
+    Developer.send(:with_scope, :find => { :select => "name" }) do
       developer = Developer.find(:first, :select => 'id, salary', :conditions => "name = 'David'")
       assert_equal 80000, developer.salary
-      assert !developer.has_attribute?(:name)
+      assert developer.has_attribute?(:id)
+      assert developer.has_attribute?(:name)
+      assert developer.has_attribute?(:salary)
     end
   end
 

activerecord/test/cases/relations_test.rb

@@ -491,6 +491,12 @@ def test_count_explicit_columns
     assert_equal 0, posts.count('comments_count')
   end
 
+  def test_multiple_selects
+    post = Post.scoped.select('comments_count').select('title').order("id ASC").first
+    assert_equal "Welcome to the weblog", post.title
+    assert_equal 2, post.comments_count
+  end
+
   def test_size
     posts = Post.scoped