Refactored the paths spec

spec/uploader/paths_spec.rb

@@ -1,25 +1,18 @@
 require 'spec_helper'
 
 describe CarrierWave::Uploader do
+  let(:uploader_class) { Class.new(CarrierWave::Uploader::Base) }
+  let(:uploader) { uploader_class.new }
 
-  before do
-    @root = CarrierWave.root
-    CarrierWave.root = nil
-    @uploader_class = Class.new(CarrierWave::Uploader::Base)
-    @uploader = @uploader_class.new
-  end
-
-  after do
-    FileUtils.rm_rf(public_path)
-    CarrierWave.root = @root
-  end
+  after { FileUtils.rm_rf(public_path) }
 
   describe '#root' do
-    it "should default to the current value of CarrierWave.root" do
-      expect(@uploader.root).to be_nil
-      CarrierWave.root = public_path
-      expect(@uploader.root).to eq(public_path)
+    describe "default behavior" do
+      before { CarrierWave.root = public_path }
+
+      it "defaults to the current value of CarrierWave.root" do
+        expect(uploader.root).to eq(public_path)
+      end
     end
   end
-
 end