Added caching option to AssetTagHelper#stylesheet_link_tag and AssetTagHelper#javascript_include_tag [DHH]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@6164 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

9 files changed, 291 insertions, 29 deletions

diff --git a/actionpack/CHANGELOG b/actionpack/CHANGELOG
index 2110d223f9..8380af610b 100644
--- a/actionpack/CHANGELOG
+++ b/actionpack/CHANGELOG
@@ -1,5 +1,18 @@
 *SVN*
 
+* Added caching option to AssetTagHelper#stylesheet_link_tag and AssetTagHelper#javascript_include_tag [DHH]. Examples:
+
+    stylesheet_link_tag :all, :cache => true # when ActionController::Base.perform_caching is false =>
+      <link href="/stylesheets/style1.css"  media="screen" rel="Stylesheet" type="text/css" />
+      <link href="/stylesheets/styleB.css"  media="screen" rel="Stylesheet" type="text/css" />
+      <link href="/stylesheets/styleX2.css" media="screen" rel="Stylesheet" type="text/css" />
+ 
+    stylesheet_link_tag :all, :cache => true # when ActionController::Base.perform_caching is true =>
+      <link href="/stylesheets/all.css"  media="screen" rel="Stylesheet" type="text/css" />
+
+  ...when caching is on, all.css is the concatenation of style1.css, styleB.css, and styleX2.css.
+  Same deal for JavaScripts.
+
 * Work around the two connection per host browser limit: use asset%d.myapp.com to distribute asset requests among asset[0123].myapp.com. Use a DNS wildcard or CNAMEs to map these hosts to your asset server. See http://www.die.net/musings/page_load_time/ for background.  [Jeremy Kemper]
 
 * Added default mime type for CSS (Mime::CSS) [DHH]
diff --git a/actionpack/lib/action_controller/base.rb b/actionpack/lib/action_controller/base.rb
index ecbe15bada..c012abc448 100755
--- a/actionpack/lib/action_controller/base.rb
+++ b/actionpack/lib/action_controller/base.rb
@@ -879,7 +879,7 @@ module ActionController #:nodoc:
 
           if text.is_a?(String)
             if response.headers['Status'][0..2] == '200' && !response.body.empty?
-              response.headers['Etag'] ||= %("#{Digest::MD5.hexdigest(text)}")
+              response.headers['Etag'] = %("#{Digest::MD5.hexdigest(text)}")
 
               if request.headers['HTTP_IF_NONE_MATCH'] == response.headers['Etag']
                 response.headers['Status'] = "304 Not Modified"
diff --git a/actionpack/lib/action_view/helpers/asset_tag_helper.rb b/actionpack/lib/action_view/helpers/asset_tag_helper.rb
index 850615632f..e72e23b20b 100644
--- a/actionpack/lib/action_view/helpers/asset_tag_helper.rb
+++ b/actionpack/lib/action_view/helpers/asset_tag_helper.rb
@@ -28,6 +28,10 @@ module ActionView
     # for server load balancing. See http://www.die.net/musings/page_load_time/
     # for background.
     module AssetTagHelper
+      ASSETS_DIR      = defined?(RAILS_ROOT) ? "#{RAILS_ROOT}/public" : "public"
+      JAVASCRIPTS_DIR = "#{ASSETS_DIR}/javascripts"
+      STYLESHEETS_DIR = "#{ASSETS_DIR}/stylesheets"
+      
       # Returns a link tag that browsers and news readers can use to auto-detect
       # an RSS or ATOM feed. The +type+ can either be <tt>:rss</tt> (default) or
       # <tt>:atom</tt>. Control the link options in url_for format using the
@@ -93,22 +97,70 @@ module ActionView
       #     <script type="text/javascript" src="/javascripts/effects.js"></script>
       #     ...
       #     <script type="text/javascript" src="/javascripts/application.js"></script> *see below
+      #
+      # * = The application.js file is only referenced if it exists
+      #
+      # You can also include all javascripts in the javascripts directory using :all as the source:
+      #
+      #   javascript_include_tag :all # =>
+      #     <script type="text/javascript" src="/javascripts/prototype.js"></script>
+      #     <script type="text/javascript" src="/javascripts/effects.js"></script>
+      #     ...
+      #     <script type="text/javascript" src="/javascripts/application.js"></script>
+      #     <script type="text/javascript" src="/javascripts/shop.js"></script>
+      #     <script type="text/javascript" src="/javascripts/checkout.js"></script>
+      #
+      # Note that the default javascript files will be included first. So Prototype and Scriptaculous are available for
+      # all subsequently included files. They
+      #
+      # == Caching multiple javascripts into one
+      #
+      # You can also cache multiple javascripts into one file, which requires less HTTP connections and can better be
+      # compressed by gzip (leading to faster transfers). Caching will only happen if ActionController::Base.perform_caching
+      # is set to true (which is the case by default for the Rails production environment, but not for the development
+      # environment). Examples:
+      #
+      #   javascript_include_tag :all, :cache => true # when ActionController::Base.perform_caching is false =>
+      #     <script type="text/javascript" src="/javascripts/prototype.js"></script>
+      #     <script type="text/javascript" src="/javascripts/effects.js"></script>
+      #     ...
+      #     <script type="text/javascript" src="/javascripts/application.js"></script>
+      #     <script type="text/javascript" src="/javascripts/shop.js"></script>
+      #     <script type="text/javascript" src="/javascripts/checkout.js"></script>
+      #
+      #   javascript_include_tag :all, :cache => true # when ActionController::Base.perform_caching is true =>
+      #     <script type="text/javascript" src="/javascripts/all.js"></script>
+      #
+      #   javascript_include_tag "prototype", "cart", "checkout", :cache => "shop" # when ActionController::Base.perform_caching is false =>
+      #     <script type="text/javascript" src="/javascripts/prototype.js"></script>
+      #     <script type="text/javascript" src="/javascripts/cart.js"></script>
+      #     <script type="text/javascript" src="/javascripts/checkout.js"></script>
+      #
+      #   javascript_include_tag "prototype", "cart", "checkout", :cache => "shop" # when ActionController::Base.perform_caching is false =>
+      #     <script type="text/javascript" src="/javascripts/shop.js"></script>
       def javascript_include_tag(*sources)
         options = sources.last.is_a?(Hash) ? sources.pop.stringify_keys : { }
+        cache   = options.delete("cache")
 
-        if sources.include?(:defaults)
-          sources = sources[0..(sources.index(:defaults))] +
-            @@javascript_default_sources.dup +
-            sources[(sources.index(:defaults) + 1)..sources.length]
+        if ActionController::Base.perform_caching && cache
+          joined_javascript_name = (cache == true ? "all" : cache) + ".js"
+          joined_javascript_path = File.join(JAVASCRIPTS_DIR, joined_javascript_name)
 
-          sources.delete(:defaults)
-          sources << "application" if defined?(RAILS_ROOT) && File.exists?("#{RAILS_ROOT}/public/javascripts/application.js")
-        end
+          if !File.exists?(joined_javascript_path)
+            File.open(joined_javascript_path, "w+") do |cache|
+              javascript_paths = expand_javascript_sources(sources).collect { |source| javascript_path(source) }
+              cache.write(join_asset_file_contents(javascript_paths))
+            end
+          end
 
-        sources.collect do |source|
-          source = javascript_path(source)
-          content_tag("script", "", { "type" => "text/javascript", "src" => source }.merge(options))
-        end.join("\n")
+          content_tag("script", "", { 
+            "type" => "text/javascript", "src" => javascript_path(joined_javascript_name)
+          }.merge(options))
+        else
+          expand_javascript_sources(sources).collect do |source|
+            content_tag("script", "", { "type" => "text/javascript", "src" => javascript_path(source) }.merge(options))
+          end.join("\n")
+        end
       end
 
       # Register one or more additional JavaScript files to be included when
@@ -148,12 +200,64 @@ module ActionView
       #   stylesheet_link_tag "random.styles", "/css/stylish" # =>
       #     <link href="/stylesheets/random.styles" media="screen" rel="Stylesheet" type="text/css" />
       #     <link href="/css/stylish.css" media="screen" rel="Stylesheet" type="text/css" />
+      #
+      # You can also include all styles in the stylesheet directory using :all as the source:
+      #
+      #   stylesheet_link_tag :all # =>
+      #     <link href="/stylesheets/style1.css"  media="screen" rel="Stylesheet" type="text/css" />
+      #     <link href="/stylesheets/styleB.css"  media="screen" rel="Stylesheet" type="text/css" />
+      #     <link href="/stylesheets/styleX2.css" media="screen" rel="Stylesheet" type="text/css" />
+      #
+      # == Caching multiple stylesheets into one
+      #
+      # You can also cache multiple stylesheets into one file, which requires less HTTP connections and can better be
+      # compressed by gzip (leading to faster transfers). Caching will only happen if ActionController::Base.perform_caching
+      # is set to true (which is the case by default for the Rails production environment, but not for the development
+      # environment). Examples:
+      #
+      #   stylesheet_link_tag :all, :cache => true # when ActionController::Base.perform_caching is false =>
+      #     <link href="/stylesheets/style1.css"  media="screen" rel="Stylesheet" type="text/css" />
+      #     <link href="/stylesheets/styleB.css"  media="screen" rel="Stylesheet" type="text/css" />
+      #     <link href="/stylesheets/styleX2.css" media="screen" rel="Stylesheet" type="text/css" />
+      #
+      #   stylesheet_link_tag :all, :cache => true # when ActionController::Base.perform_caching is true =>
+      #     <link href="/stylesheets/all.css"  media="screen" rel="Stylesheet" type="text/css" />
+      #
+      #   stylesheet_link_tag "shop", "cart", "checkout", :cache => "payment" # when ActionController::Base.perform_caching is false =>
+      #     <link href="/stylesheets/shop.css"  media="screen" rel="Stylesheet" type="text/css" />
+      #     <link href="/stylesheets/cart.css"  media="screen" rel="Stylesheet" type="text/css" />
+      #     <link href="/stylesheets/checkout.css" media="screen" rel="Stylesheet" type="text/css" />
+      #
+      #   stylesheet_link_tag "shop", "cart", "checkout", :cache => "payment" # when ActionController::Base.perform_caching is true =>
+      #     <link href="/stylesheets/payment.css"  media="screen" rel="Stylesheet" type="text/css" />
       def stylesheet_link_tag(*sources)
         options = sources.last.is_a?(Hash) ? sources.pop.stringify_keys : { }
-        sources.collect do |source|
-          source = stylesheet_path(source)
-          tag("link", { "rel" => "Stylesheet", "type" => "text/css", "media" => "screen", "href" => source }.merge(options))
-        end.join("\n")
+        cache   = options.delete("cache")
+
+        if ActionController::Base.perform_caching && cache
+          joined_stylesheet_name = (cache == true ? "all" : cache) + ".css"
+          joined_stylesheet_path = File.join(STYLESHEETS_DIR, joined_stylesheet_name)
+
+          if !File.exists?(joined_stylesheet_path)
+            File.open(joined_stylesheet_path, "w+") do |cache|
+              stylesheet_paths = expand_stylesheet_sources(sources).collect { |source| stylesheet_path(source) }
+              cache.write(join_asset_file_contents(stylesheet_paths))
+            end
+          end
+
+          tag("link", {
+            "rel" => "Stylesheet", "type" => "text/css", "media" => "screen",
+            "href" => stylesheet_path(joined_stylesheet_name)
+          }.merge(options))
+        else
+          options.delete("cache")
+
+          expand_stylesheet_sources(sources).collect do |source|
+            tag("link", { 
+              "rel" => "Stylesheet", "type" => "text/css", "media" => "screen", "href" => stylesheet_path(source)
+            }.merge(options))
+          end.join("\n")
+        end
       end
 
       # Computes the path to an image asset in the public images directory.
@@ -216,6 +320,7 @@ module ActionView
         # request protocol.
         def compute_public_path(source, dir, ext)
           source += ".#{ext}" if File.extname(source).blank?
+
           if source =~ %r{^[-a-z]+://}
             source
           else
@@ -245,15 +350,45 @@ module ActionView
         # modification time as its cache-busting asset id.
         def rails_asset_id(source)
           ENV["RAILS_ASSET_ID"] ||
-            File.mtime("#{RAILS_ROOT}/public/#{source}").to_i.to_s rescue ""
+            File.mtime(File.join(ASSETS_DIR, source)).to_i.to_s rescue ""
         end
 
         # Break out the asset path rewrite so you wish to put the asset id
         # someplace other than the query string.
         def rewrite_asset_path!(source)
           asset_id = rails_asset_id(source)
-          source << "?#{asset_id}" if defined?(RAILS_ROOT) && !asset_id.blank?
+          source << "?#{asset_id}" if !asset_id.blank?
+        end
+
+        def expand_javascript_sources(sources)          
+          case
+          when sources.include?(:all)
+            all_javascript_files = Dir[File.join(JAVASCRIPTS_DIR, '*.js')].collect { |file| File.basename(file).split(".", 0).first }
+            sources = ((@@javascript_default_sources.dup & all_javascript_files) + all_javascript_files).uniq
+
+          when sources.include?(:defaults)
+            sources = sources[0..(sources.index(:defaults))] + 
+              @@javascript_default_sources.dup + 
+              sources[(sources.index(:defaults) + 1)..sources.length]
+
+            sources.delete(:defaults)
+            sources << "application" if File.exists?(File.join(JAVASCRIPTS_DIR, "application.js"))
+          end
+
+          sources
+        end
+
+        def expand_stylesheet_sources(sources)
+          if sources.first == :all
+            sources = Dir[File.join(STYLESHEETS_DIR, '*.css')].collect { |file| File.basename(file).split(".", 1).first }
+          else
+            sources
+          end
+        end
+
+        def join_asset_file_contents(paths)
+          paths.collect { |path| File.read(File.join(ASSETS_DIR, path.split("?").first)) }.join("\n\n")          
         end
     end
   end
-end
+end
\ No newline at end of file
diff --git a/actionpack/test/controller/render_test.rb b/actionpack/test/controller/render_test.rb
index fb784d3e02..21f5fb1f51 100644
--- a/actionpack/test/controller/render_test.rb
+++ b/actionpack/test/controller/render_test.rb
@@ -335,6 +335,12 @@ class RenderTest < Test::Unit::TestCase
     assert_equal expected_etag, @response.headers['Etag']
   end
 
+  def test_etag_should_govern_renders_with_layouts_too
+    get :builder_layout_test
+    assert_equal etag_for("<wrapper>\n<html>\n  <p>Hello </p>\n<p>This is grand!</p>\n</html>\n</wrapper>\n"), @response.headers['Etag']
+  end
+
+
   protected
     def assert_deprecated_render(&block)
       assert_deprecated(/render/, &block)
diff --git a/actionpack/test/fixtures/public/javascripts/bank.js b/actionpack/test/fixtures/public/javascripts/bank.js
new file mode 100644
index 0000000000..4a1bee7182
--- /dev/null
+++ b/actionpack/test/fixtures/public/javascripts/bank.js
@@ -0,0 +1 @@
+// bank js
\ No newline at end of file
diff --git a/actionpack/test/fixtures/public/javascripts/robber.js b/actionpack/test/fixtures/public/javascripts/robber.js
new file mode 100644
index 0000000000..eb82fcbdf4
--- /dev/null
+++ b/actionpack/test/fixtures/public/javascripts/robber.js
@@ -0,0 +1 @@
+// robber js
\ No newline at end of file
diff --git a/actionpack/test/fixtures/public/stylesheets/bank.css b/actionpack/test/fixtures/public/stylesheets/bank.css
new file mode 100644
index 0000000000..ea161b12b2
--- /dev/null
+++ b/actionpack/test/fixtures/public/stylesheets/bank.css
@@ -0,0 +1 @@
+/* bank.css */
\ No newline at end of file
diff --git a/actionpack/test/fixtures/public/stylesheets/robber.css b/actionpack/test/fixtures/public/stylesheets/robber.css
new file mode 100644
index 0000000000..0fdd00a6a5
--- /dev/null
+++ b/actionpack/test/fixtures/public/stylesheets/robber.css
@@ -0,0 +1 @@
+/* robber.css */
\ No newline at end of file
diff --git a/actionpack/test/template/asset_tag_helper_test.rb b/actionpack/test/template/asset_tag_helper_test.rb
index 33705b8e7c..8b8a426bf6 100644
--- a/actionpack/test/template/asset_tag_helper_test.rb
+++ b/actionpack/test/template/asset_tag_helper_test.rb
@@ -6,7 +6,25 @@ class AssetTagHelperTest < Test::Unit::TestCase
   include ActionView::Helpers::AssetTagHelper
 
   def setup
-    Object.send(:const_set, :RAILS_ROOT, File.dirname(__FILE__) + "/../fixtures/")
+    silence_warnings do
+      ActionView::Helpers::AssetTagHelper.send(
+        :const_set,
+        :JAVASCRIPTS_DIR,
+        File.dirname(__FILE__) + "/../fixtures/public/javascripts"
+      )
+
+      ActionView::Helpers::AssetTagHelper.send(
+        :const_set,
+        :STYLESHEETS_DIR,
+        File.dirname(__FILE__) + "/../fixtures/public/stylesheets"
+      )
+
+      ActionView::Helpers::AssetTagHelper.send(
+        :const_set,
+        :ASSETS_DIR,
+        File.dirname(__FILE__) + "/../fixtures/public"
+      )
+    end
 
     @controller = Class.new do
       attr_accessor :request
@@ -23,7 +41,7 @@ class AssetTagHelperTest < Test::Unit::TestCase
   end
 
   def teardown
-    Object.send(:remove_const, :RAILS_ROOT) if defined?(RAILS_ROOT)
+    ActionController::Base.perform_caching = false
     ENV["RAILS_ASSET_ID"] = nil
   end
 
@@ -53,9 +71,10 @@ class AssetTagHelperTest < Test::Unit::TestCase
     %(javascript_include_tag("xmlhr.js")) => %(<script src="/javascripts/xmlhr.js" type="text/javascript"></script>),
     %(javascript_include_tag("xmlhr", :lang => "vbscript")) => %(<script lang="vbscript" src="/javascripts/xmlhr.js" type="text/javascript"></script>),
     %(javascript_include_tag("common.javascript", "/elsewhere/cools")) => %(<script src="/javascripts/common.javascript" type="text/javascript"></script>\n<script src="/elsewhere/cools.js" type="text/javascript"></script>),
-    %(javascript_include_tag(:defaults)) => %(<script src="/javascripts/prototype.js" type="text/javascript"></script>\n<script src="/javascripts/effects.js" type="text/javascript"></script>\n<script src="/javascripts/dragdrop.js" type="text/javascript"></script>\n<script src="/javascripts/controls.js" type="text/javascript"></script>),
-    %(javascript_include_tag(:defaults, "test")) => %(<script src="/javascripts/prototype.js" type="text/javascript"></script>\n<script src="/javascripts/effects.js" type="text/javascript"></script>\n<script src="/javascripts/dragdrop.js" type="text/javascript"></script>\n<script src="/javascripts/controls.js" type="text/javascript"></script>\n<script src="/javascripts/test.js" type="text/javascript"></script>),
-    %(javascript_include_tag("test", :defaults)) => %(<script src="/javascripts/test.js" type="text/javascript"></script>\n<script src="/javascripts/prototype.js" type="text/javascript"></script>\n<script src="/javascripts/effects.js" type="text/javascript"></script>\n<script src="/javascripts/dragdrop.js" type="text/javascript"></script>\n<script src="/javascripts/controls.js" type="text/javascript"></script>)
+    %(javascript_include_tag(:defaults)) => %(<script src="/javascripts/prototype.js" type="text/javascript"></script>\n<script src="/javascripts/effects.js" type="text/javascript"></script>\n<script src="/javascripts/dragdrop.js" type="text/javascript"></script>\n<script src="/javascripts/controls.js" type="text/javascript"></script>\n<script src="/javascripts/application.js" type="text/javascript"></script>),
+    %(javascript_include_tag(:all)) => %(<script src="/javascripts/application.js" type="text/javascript"></script>\n<script src="/javascripts/bank.js" type="text/javascript"></script>\n<script src="/javascripts/robber.js" type="text/javascript"></script>),
+    %(javascript_include_tag(:defaults, "test")) => %(<script src="/javascripts/prototype.js" type="text/javascript"></script>\n<script src="/javascripts/effects.js" type="text/javascript"></script>\n<script src="/javascripts/dragdrop.js" type="text/javascript"></script>\n<script src="/javascripts/controls.js" type="text/javascript"></script>\n<script src="/javascripts/test.js" type="text/javascript"></script>\n<script src="/javascripts/application.js" type="text/javascript"></script>),
+    %(javascript_include_tag("test", :defaults)) => %(<script src="/javascripts/test.js" type="text/javascript"></script>\n<script src="/javascripts/prototype.js" type="text/javascript"></script>\n<script src="/javascripts/effects.js" type="text/javascript"></script>\n<script src="/javascripts/dragdrop.js" type="text/javascript"></script>\n<script src="/javascripts/controls.js" type="text/javascript"></script>\n<script src="/javascripts/application.js" type="text/javascript"></script>)
   }
 
   StylePathToTag = {
@@ -71,6 +90,8 @@ class AssetTagHelperTest < Test::Unit::TestCase
     %(stylesheet_link_tag("/dir/file")) => %(<link href="/dir/file.css" media="screen" rel="Stylesheet" type="text/css" />),
     %(stylesheet_link_tag("dir/file")) => %(<link href="/stylesheets/dir/file.css" media="screen" rel="Stylesheet" type="text/css" />),
     %(stylesheet_link_tag("style", :media => "all")) => %(<link href="/stylesheets/style.css" media="all" rel="Stylesheet" type="text/css" />),
+    %(stylesheet_link_tag(:all)) => %(<link href="/stylesheets/bank.css" media="screen" rel="Stylesheet" type="text/css" />\n<link href="/stylesheets/robber.css" media="screen" rel="Stylesheet" type="text/css" />),
+    %(stylesheet_link_tag(:all, :media => "all")) => %(<link href="/stylesheets/bank.css" media="all" rel="Stylesheet" type="text/css" />\n<link href="/stylesheets/robber.css" media="all" rel="Stylesheet" type="text/css" />),
     %(stylesheet_link_tag("random.styles", "/css/stylish")) => %(<link href="/stylesheets/random.styles" media="screen" rel="Stylesheet" type="text/css" />\n<link href="/css/stylish.css" media="screen" rel="Stylesheet" type="text/css" />),
     %(stylesheet_link_tag("http://www.example.com/styles/style")) => %(<link href="http://www.example.com/styles/style.css" media="screen" rel="Stylesheet" type="text/css" />)
   }
@@ -106,20 +127,19 @@ class AssetTagHelperTest < Test::Unit::TestCase
   end
 
   def test_javascript_include_tag
-    Object.send(:remove_const, :RAILS_ROOT) if defined?(RAILS_ROOT)
+    ENV["RAILS_ASSET_ID"] = ""
     JavascriptIncludeToTag.each { |method, tag| assert_dom_equal(tag, eval(method)) }
-    Object.send(:const_set, :RAILS_ROOT, File.dirname(__FILE__) + "/../fixtures/")
 
     ENV["RAILS_ASSET_ID"] = "1"
     assert_dom_equal(%(<script src="/javascripts/prototype.js?1" type="text/javascript"></script>\n<script src="/javascripts/effects.js?1" type="text/javascript"></script>\n<script src="/javascripts/dragdrop.js?1" type="text/javascript"></script>\n<script src="/javascripts/controls.js?1" type="text/javascript"></script>\n<script src="/javascripts/application.js?1" type="text/javascript"></script>), javascript_include_tag(:defaults))
   end
 
   def test_register_javascript_include_default
-    Object.send(:remove_const, :RAILS_ROOT) if defined?(RAILS_ROOT)
+    ENV["RAILS_ASSET_ID"] = ""
     ActionView::Helpers::AssetTagHelper::register_javascript_include_default 'slider'
-    assert_dom_equal  %(<script src="/javascripts/prototype.js" type="text/javascript"></script>\n<script src="/javascripts/effects.js" type="text/javascript"></script>\n<script src="/javascripts/dragdrop.js" type="text/javascript"></script>\n<script src="/javascripts/controls.js" type="text/javascript"></script>\n<script src="/javascripts/slider.js" type="text/javascript"></script>), javascript_include_tag(:defaults)
+    assert_dom_equal  %(<script src="/javascripts/prototype.js" type="text/javascript"></script>\n<script src="/javascripts/effects.js" type="text/javascript"></script>\n<script src="/javascripts/dragdrop.js" type="text/javascript"></script>\n<script src="/javascripts/controls.js" type="text/javascript"></script>\n<script src="/javascripts/slider.js" type="text/javascript"></script>\n<script src="/javascripts/application.js" type="text/javascript"></script>), javascript_include_tag(:defaults)
     ActionView::Helpers::AssetTagHelper::register_javascript_include_default 'lib1', '/elsewhere/blub/lib2'
-    assert_dom_equal  %(<script src="/javascripts/prototype.js" type="text/javascript"></script>\n<script src="/javascripts/effects.js" type="text/javascript"></script>\n<script src="/javascripts/dragdrop.js" type="text/javascript"></script>\n<script src="/javascripts/controls.js" type="text/javascript"></script>\n<script src="/javascripts/slider.js" type="text/javascript"></script>\n<script src="/javascripts/lib1.js" type="text/javascript"></script>\n<script src="/elsewhere/blub/lib2.js" type="text/javascript"></script>), javascript_include_tag(:defaults)
+    assert_dom_equal  %(<script src="/javascripts/prototype.js" type="text/javascript"></script>\n<script src="/javascripts/effects.js" type="text/javascript"></script>\n<script src="/javascripts/dragdrop.js" type="text/javascript"></script>\n<script src="/javascripts/controls.js" type="text/javascript"></script>\n<script src="/javascripts/slider.js" type="text/javascript"></script>\n<script src="/javascripts/lib1.js" type="text/javascript"></script>\n<script src="/elsewhere/blub/lib2.js" type="text/javascript"></script>\n<script src="/javascripts/application.js" type="text/javascript"></script>), javascript_include_tag(:defaults)
   end
   
   def test_stylesheet_path
@@ -127,6 +147,7 @@ class AssetTagHelperTest < Test::Unit::TestCase
   end
 
   def test_stylesheet_link_tag
+    ENV["RAILS_ASSET_ID"] = ""
     StyleLinkToTag.each { |method, tag| assert_dom_equal(tag, eval(method)) }
   end
 
@@ -169,6 +190,89 @@ class AssetTagHelperTest < Test::Unit::TestCase
     image_tag(source)
     assert_equal copy, source
   end
+
+
+  def test_caching_javascript_include_tag_when_caching_on
+    ENV["RAILS_ASSET_ID"] = ""
+    ActionController::Base.perform_caching = true
+    
+    assert_dom_equal(
+      %(<script src="/javascripts/all.js" type="text/javascript"></script>),
+      javascript_include_tag(:all, :cache => true)
+    )
+
+    assert File.exists?(File.join(ActionView::Helpers::AssetTagHelper::JAVASCRIPTS_DIR, 'all.js'))
+    
+    assert_dom_equal(
+      %(<script src="/javascripts/money.js" type="text/javascript"></script>),
+      javascript_include_tag(:all, :cache => "money")
+    )
+
+    assert File.exists?(File.join(ActionView::Helpers::AssetTagHelper::JAVASCRIPTS_DIR, 'money.js'))
+  ensure
+    File.delete(File.join(ActionView::Helpers::AssetTagHelper::JAVASCRIPTS_DIR, 'all.js'))
+    File.delete(File.join(ActionView::Helpers::AssetTagHelper::JAVASCRIPTS_DIR, 'money.js'))
+  end
+  
+  def test_caching_javascript_include_tag_when_caching_off
+    ENV["RAILS_ASSET_ID"] = ""
+    ActionController::Base.perform_caching = false
+    
+    assert_dom_equal(
+      %(<script src="/javascripts/application.js" type="text/javascript"></script>\n<script src="/javascripts/bank.js" type="text/javascript"></script>\n<script src="/javascripts/robber.js" type="text/javascript"></script>),
+      javascript_include_tag(:all, :cache => true)
+    )
+
+    assert !File.exists?(File.join(ActionView::Helpers::AssetTagHelper::JAVASCRIPTS_DIR, 'all.js'))
+    
+    assert_dom_equal(
+      %(<script src="/javascripts/application.js" type="text/javascript"></script>\n<script src="/javascripts/bank.js" type="text/javascript"></script>\n<script src="/javascripts/robber.js" type="text/javascript"></script>),
+      javascript_include_tag(:all, :cache => "money")
+    )
+
+    assert !File.exists?(File.join(ActionView::Helpers::AssetTagHelper::JAVASCRIPTS_DIR, 'money.js'))
+  end
+
+  def test_caching_stylesheet_link_tag_when_caching_on
+    ENV["RAILS_ASSET_ID"] = ""
+    ActionController::Base.perform_caching = true
+    
+    assert_dom_equal(
+      %(<link href="/stylesheets/all.css" media="screen" rel="Stylesheet" type="text/css" />),
+      stylesheet_link_tag(:all, :cache => true)
+    )
+
+    assert File.exists?(File.join(ActionView::Helpers::AssetTagHelper::STYLESHEETS_DIR, 'all.css'))
+
+    assert_dom_equal(
+      %(<link href="/stylesheets/money.css" media="screen" rel="Stylesheet" type="text/css" />),
+      stylesheet_link_tag(:all, :cache => "money")
+    )
+
+    assert File.exists?(File.join(ActionView::Helpers::AssetTagHelper::STYLESHEETS_DIR, 'money.css'))
+  ensure
+    File.delete(File.join(ActionView::Helpers::AssetTagHelper::STYLESHEETS_DIR, 'all.css'))
+    File.delete(File.join(ActionView::Helpers::AssetTagHelper::STYLESHEETS_DIR, 'money.css'))
+  end
+  
+  def test_caching_stylesheet_include_tag_when_caching_off
+    ENV["RAILS_ASSET_ID"] = ""
+    ActionController::Base.perform_caching = false
+    
+    assert_dom_equal(
+      %(<link href="/stylesheets/bank.css" media="screen" rel="Stylesheet" type="text/css" />\n<link href="/stylesheets/robber.css" media="screen" rel="Stylesheet" type="text/css" />),
+      stylesheet_link_tag(:all, :cache => true)
+    )
+
+    assert !File.exists?(File.join(ActionView::Helpers::AssetTagHelper::STYLESHEETS_DIR, 'all.css'))
+    
+    assert_dom_equal(
+      %(<link href="/stylesheets/bank.css" media="screen" rel="Stylesheet" type="text/css" />\n<link href="/stylesheets/robber.css" media="screen" rel="Stylesheet" type="text/css" />),
+      stylesheet_link_tag(:all, :cache => "money")
+    )
+
+    assert !File.exists?(File.join(ActionView::Helpers::AssetTagHelper::STYLESHEETS_DIR, 'money.css'))
+  end
 end
 
 class AssetTagHelperNonVhostTest < Test::Unit::TestCase