Set ETag header for directory listings

lib/remote_storage/swift.rb

@@ -75,10 +75,12 @@ module RemoteStorage
     end
 
     def get_directory_listing(user, directory)
-      # TODO add ETag header
       # TODO check IF_NONE_MATCH header
+      etag = redis.hget "rs_meta:#{user}:#{directory}/", "etag"
+
 
       server.headers["Content-Type"] = "application/json"
+      server.headers["ETag"] = %Q("#{etag}")
 
       listing = {
         "@context" => "http://remotestorage.io/spec/folder-description",

spec/swift/app_spec.rb

@@ -176,6 +176,13 @@ describe "App" do
 
       describe "directory listings" do
 
+        it "has an ETag in the header" do
+          get "/phil/food/"
+
+          last_response.status.must_equal 200
+          last_response.headers["ETag"].must_equal "\"bla\""
+        end
+
         it "contains all items in the directory" do
           get "/phil/food/"