first draft of jammit_debug

Author: jashkenas

index.html

@@ -251,6 +251,15 @@ <h2 id="configuration">Configuration</h2>
           to compress your JavaScript.
         </td>
       </tr>
+      <tr>
+        <td><b>allow_debugging</b></td>
+        <td><tt>on&nbsp;|&nbsp;off</tt></td>
+        <td class="definition">
+          Defaults to <b>on</b>. Leaving it on allows you to pass 
+          <tt>jammit_debug=true</tt> as a query parameter, in order to load the
+          page with uncompressed, unpackaged assets in production.
+        </td>
+      </tr>
       <tr>
         <td><b>template_function</b></td>
         <td><tt>on&nbsp;|&nbsp;off&nbsp;|&nbsp;...</tt></td>
@@ -349,6 +358,12 @@ <h2 id="usage">Usage</h2>
       In all other environments, or if <b>package_assets</b> is set to "<b>always</b>",
       you'll get tags for the merged packages.
     </p>
+    
+    <p>
+      If <b>allow_debugging</b> is left on, you'll be able to request the development
+      version of the assets for any given page, by passing <tt>jammit_debug=true</tt>
+      as a query parameter.
+    </p>
 
     <p>
       You can easily use Jammit within your Rakefile, and other scripts:

lib/jammit.rb

@@ -50,7 +50,7 @@ class << self
                 :embed_assets, :package_assets, :compress_assets, :gzip_assets,
                 :package_path, :mhtml_enabled, :include_jst_script, :config_path,
                 :javascript_compressor, :compressor_options, :css_compressor_options,
-                :template_extension, :template_extension_matcher
+                :template_extension, :template_extension_matcher, :allow_debugging
   end
 
   # The minimal required configuration.
@@ -70,6 +70,7 @@ def self.load_configuration(config_path, soft=false)
     @embed_assets           = conf[:embed_assets] || conf[:embed_images]
     @compress_assets        = !(conf[:compress_assets] == false)
     @gzip_assets            = !(conf[:gzip_assets] == false)
+    @allow_debugging        = !(conf[:allow_debugging] == false)
     @mhtml_enabled          = @embed_assets && @embed_assets != "datauri"
     @compressor_options     = symbolize_keys(conf[:compressor_options] || {})
     @css_compressor_options = symbolize_keys(conf[:css_compressor_options] || {})

lib/jammit/helper.rb

@@ -16,7 +16,7 @@ module Helper
     # compressed CSS, and in development the stylesheet URLs are passed verbatim.
     def include_stylesheets(*packages)
       options = packages.extract_options!
-      return individual_stylesheets(packages, options) unless Jammit.package_assets
+      return individual_stylesheets(packages, options) unless should_package?
       disabled = (options.delete(:embed_assets) == false) || (options.delete(:embed_images) == false)
       return html_safe(packaged_stylesheets(packages, options)) if disabled || !Jammit.embed_assets
       return html_safe(embedded_image_stylesheets(packages, options))
@@ -26,7 +26,7 @@ def include_stylesheets(*packages)
     # except in development, where it references the individual scripts.
     def include_javascripts(*packages)
       tags = packages.map do |pack|
-        Jammit.package_assets ? Jammit.asset_url(pack, :js) : Jammit.packager.individual_urls(pack.to_sym, :js)
+        should_package? ? Jammit.asset_url(pack, :js) : Jammit.packager.individual_urls(pack.to_sym, :js)
       end
       html_safe(javascript_include_tag(tags.flatten))
     end
@@ -40,6 +40,10 @@ def include_templates(*packages)
 
     private
 
+    def should_package?
+      Jammit.package_assets && !(Jammit.allow_debugging && params[:jammit_debug])
+    end
+
     def html_safe(string)
       string.respond_to?(:html_safe) ? string.html_safe : string
     end

test/unit/test_jammit_helpers.rb

@@ -27,6 +27,10 @@ def initialize(*args)
     end
   end
 
+  def params
+    @debug ? {:jammit_debug => true} : {}
+  end
+
   def test_include_stylesheets
     assert include_stylesheets(:css_test) == File.read('test/fixtures/tags/css_includes.html')
   end
@@ -51,7 +55,7 @@ def test_include_templates_with_diff_ext
     assert include_javascripts(:jst_test_diff_ext) == '<script src="/assets/jst_test_diff_ext.js?101" type="text/javascript"></script>'
   end
 
-  def test_individual_assets_in_development_do
+  def test_individual_assets_in_development
     Jammit.instance_variable_set(:@package_assets, false)
     assert include_stylesheets(:css_test) == File.read('test/fixtures/tags/css_individual_includes.html')
     assert include_javascripts(:js_test_with_templates) == File.read('test/fixtures/tags/js_individual_includes.html')
@@ -64,4 +68,11 @@ def test_individual_assets_in_development_do
     Jammit.reload!
   end
 
+  def test_individual_assets_while_debugging
+    @debug = true
+    assert include_stylesheets(:css_test) == File.read('test/fixtures/tags/css_individual_includes.html')
+    assert include_javascripts(:js_test_with_templates) == File.read('test/fixtures/tags/js_individual_includes.html')
+    @debug = false
+  end
+
 end