Replace Bzip2Uploader#decompressed with #decompressed_path

app/uploaders/bzip2_uploader.rb

@@ -1,17 +1,15 @@
 class Bzip2Uploader < BaseUploader
 
-  def decompressed
+  def decompressed_path
     return unless file
+    out_path = "#{path}.decompressed"
 
-    unless @decompressed
+    unless File.exist?(out_path)
       cache_stored_file! unless cached?
-
-      file = IO.popen("bzip2 -d -c #{path}", "r")
-      @decompressed = file.read
-      file.close
+      system("bzip2 -d -k -c #{path} >#{out_path}")
     end
 
-    @decompressed
+    out_path
   end
 
 end

spec/uploaders/bzip2_uploader_spec.rb

@@ -4,20 +4,24 @@ describe Bzip2Uploader do
   let(:uploader) { Bzip2Uploader.new(user, :photo) }
   let(:user) { User.new }
 
-  describe '#decompressed' do
+  describe '#decompressed_path' do
+    subject { uploader.decompressed_path }
+
     context "when file wasn't stored" do
       it 'returns nil' do
-        expect(uploader.decompressed).to be(nil)
+        expect(subject).to be(nil)
       end
     end
 
     context "when file was stored" do
+      let(:decompressed_data) { File.read(subject) }
+
       before do
         uploader.store!(File.open('spec/fixtures/munch.bz2'))
       end
 
-      it 'returns decompressed data as a string' do
-        expect(uploader.decompressed).to eq(<<EOS)
+      it 'returns a path to the decompressed data' do
+        expect(decompressed_data).to eq(<<EOS)
 Edvard Munch - The Scream
 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXP
 XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXY?"""  .