Move precompile task to Sprockets::StaticCompiler

actionpack/lib/sprockets/assets.rake

@@ -20,30 +20,10 @@ namespace :assets do
       config = Rails.application.config
       env    = Rails.application.assets
       target = Pathname.new(File.join(Rails.public_path, config.assets.prefix))
-      manifest = {}
       manifest_path = config.assets.manifest || target
 
-      config.assets.precompile.each do |path|
+      static_compiler = Sprockets::StaticCompiler.new(env, target, :digest => config.assets.digest)
-        env.each_logical_path do |logical_path|
+      manifest = static_compiler.precompile(config.assets.precompile)
-          if path.is_a?(Regexp)
-            next unless path.match(logical_path)
-          elsif path.is_a?(Proc)
-            next unless path.call(logical_path)
-          else
-            next unless File.fnmatch(path.to_s, logical_path)
-          end
-
-          if asset = env.find_asset(logical_path)
-            asset_path = config.assets.digest ? asset.digest_path : logical_path
-            manifest[logical_path] = asset_path
-            filename = target.join(asset_path)
-
-            mkdir_p filename.dirname
-            asset.write_to(filename)
-            asset.write_to("#{filename}.gz") if filename.to_s =~ /\.(css|js)$/
-          end
-        end
-      end
 
       File.open("#{manifest_path}/manifest.yml", 'wb') do |f|
         YAML.dump(manifest, f)

actionpack/lib/sprockets/railtie.rb

@@ -2,6 +2,7 @@ module Sprockets
   autoload :Helpers, "sprockets/helpers"
   autoload :LazyCompressor, "sprockets/compressors"
   autoload :NullCompressor, "sprockets/compressors"
+  autoload :StaticCompiler, "sprockets/static_compiler"
 
   # TODO: Get rid of config.assets.enabled
   class Railtie < ::Rails::Railtie

actionpack/lib/sprockets/static_compiler.rb

@@ -0,0 +1,53 @@
+require 'fileutils'
+require 'pathname'
+
+module Sprockets
+  class StaticCompiler
+    attr_accessor :env, :target, :digest
+
+    def initialize(env, target, options = {})
+      @env = env
+      @target = target
+      @digest = options.key?(:digest) ? options.delete(:digest) : true
+    end
+
+    def precompile(paths)
+      Rails.application.config.assets.digest = digest
+      manifest = {}
+
+      env.each_logical_path do |logical_path|
+        next unless precompile_path?(logical_path, paths)
+        if asset = env.find_asset(logical_path)
+          manifest[logical_path] = compile(asset)
+        end
+      end
+      manifest
+    end
+
+    def compile(asset)
+      asset_path = digest_asset(asset)
+      filename = target.join(asset_path)
+      FileUtils.mkdir_p filename.dirname
+      asset.write_to(filename)
+      asset.write_to("#{filename}.gz") if filename.to_s =~ /\.(css|js)$/
+      asset_path
+    end
+
+    def precompile_path?(logical_path, paths)
+      paths.each do |path|
+        if path.is_a?(Regexp)
+          return true if path.match(logical_path)
+        elsif path.is_a?(Proc)
+          return true if path.call(logical_path)
+        else
+          return true if File.fnmatch(path.to_s, logical_path)
+        end
+      end
+      false
+    end
+
+    def digest_asset(asset)
+      digest ? asset.digest_path : asset.logical_path
+    end
+  end
+end