Add assets.cache_package_paths and unit test.

.gitignore

@@ -1,4 +1,5 @@
 /.rvmrc
 /.sass-cache
 /doc/
-*.gem
+*.gem
+.DS_Store

README.md

@@ -560,6 +560,11 @@ class App < Sinatra::Base
 end
 ```
 
+### assets.cache_package_paths
+Cache the list of files matching each package definition.
+
+Defaults to `false` in development, `true` in other environments. 
+
 ## Helpers
 
 These are helpers you can use in your views.

lib/sinatra/assetpack/options.rb

@@ -173,6 +173,15 @@ def js_or_css(type, name, *args)
       attrib :prebuild          # Bool
       attrib :cache_dynamic_assets # Bool
 
+      def cache_package_paths(*args)
+        if args.empty?
+          @cache_package_paths = (app.settings.environment != :development) if @cache_package_paths.nil?
+          @cache_package_paths
+        else
+          @cache_package_paths = args.first
+        end
+      end
+
       def expires(*args)
         if args.empty?
           @expires
@@ -277,6 +286,9 @@ def files(match=nil)
       #     glob(['spec1', 'spec2' ...])
       #
       def glob(match)
+
+        @reload_files_cache = true unless cache_package_paths
+
         paths = Array.new(match) # Force array-ness
 
         paths.map! do |spec|

test/cache_package_paths_test.rb

@@ -0,0 +1,41 @@
+require File.expand_path('../test_helper', __FILE__)
+
+class CachePackagePathsTest < UnitTest
+  class App < Main
+    assets {
+      serve '/css', :from => 'app/css'
+      css :a, [ '/css/**/style*.css' ]
+    }
+
+    get('/pkg') { css :a }
+  end
+
+  def app
+    App
+  end
+
+  test "package contents are not cached in development" do
+    app.settings.stubs(:environment).returns(:development)
+    get '/pkg'
+    assert_equal 200, last_response.status
+    assert_match %r{css/style\.\w{32}\.css}, body
+
+    begin
+      file = Tempfile.new(['style', '.scss'], File.join(File.dirname(__FILE__), "app", "app", "css"))
+      file.write("body{color: red;}") 
+      file.flush
+
+      get '/pkg'
+      assert_equal 200, last_response.status
+      assert_match %r{css/style\.\w{32}\.css}, body
+      assert_match %r{css/#{File.basename(file.path).chomp(".scss")}\.\w{32}\.css}, body
+
+    ensure
+      unless file == nil
+          file.close 
+          file.delete
+      end
+    end
+  end
+
+end