Missing :js template falls back to :html, so you don't have to explicitly specify template format everywhere, breaking old code

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@9119 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

2 files changed, 37 insertions, 4 deletions

diff --git a/actionpack/lib/action_view/template_finder.rb b/actionpack/lib/action_view/template_finder.rb
index 69832e9b4c..0fb5eaa65e 100644
--- a/actionpack/lib/action_view/template_finder.rb
+++ b/actionpack/lib/action_view/template_finder.rb
@@ -131,15 +131,20 @@ module ActionView #:nodoc:
     #   # => "rhtml"
     #
     def pick_template_extension(template_path)
-      find_template_extension_from_handler(template_path) || find_template_extension_from_first_render
+      if extension = find_template_extension_from_handler(template_path, @template.template_format) || find_template_extension_from_first_render
+        extension
+      elsif @template.template_format == :js && extension = find_template_extension_from_handler(template_path, :html)
+        @template.template_format = :html
+        extension
+      end
     end
 
-    def find_template_extension_from_handler(template_path)
-      formatted_template_path = "#{template_path}.#{@template.template_format}"
+    def find_template_extension_from_handler(template_path, template_format = @template.template_format)
+      formatted_template_path = "#{template_path}.#{template_format}"
 
       view_paths.each do |path|
         if (extensions = @@file_extension_cache[path][formatted_template_path]).any?
-          return "#{@template.template_format}.#{extensions.first}"
+          return "#{template_format}.#{extensions.first}"
         elsif (extensions = @@file_extension_cache[path][template_path]).any?
           return extensions.first.to_s
         end
diff --git a/actionpack/test/template/template_object_test.rb b/actionpack/test/template/template_object_test.rb
index 780df17f0c..b3a33938cf 100644
--- a/actionpack/test/template/template_object_test.rb
+++ b/actionpack/test/template/template_object_test.rb
@@ -59,4 +59,32 @@ class TemplateObjectTest < Test::Unit::TestCase
     end
   end
   
+  class PartialTemplateFallbackTest < Test::Unit::TestCase
+    def setup
+      @view = ActionView::Base.new(LOAD_PATH_ROOT)
+      @path = 'test/layout_for_partial'
+    end
+
+    def test_default
+      template = ActionView::PartialTemplate.new(@view, @path, nil)
+      assert_equal 'test/_layout_for_partial', template.path
+      assert_equal 'erb', template.extension
+      assert_equal :html, @view.template_format
+    end
+
+    def test_js
+      @view.template_format = :js
+      template = ActionView::PartialTemplate.new(@view, @path, nil)
+      assert_equal 'test/_layout_for_partial', template.path
+      assert_equal 'erb', template.extension
+      assert_equal :html, @view.template_format
+    end
+
+    def test_xml
+      @view.template_format = :xml
+      assert_raise ActionView::ActionViewError do
+        ActionView::PartialTemplate.new(@view, @path, nil)
+      end
+    end
+  end
 end