Fixing 'pull/22 : HttpCacheResponder returns 304 even when the collec…

…tion has different set of resources'. Last-Modified header will not be set for GET on Collection

lib/responders/http_cache_responder.rb

@@ -22,9 +22,7 @@ def to_format
   protected
 
     def do_http_cache!
-      timestamp = resources.flatten.map do |resource|
-        resource.updated_at.try(:utc) if resource.respond_to?(:updated_at)
-      end.compact.max
+      timestamp = resource.updated_at.try(:utc) if resource.respond_to?(:updated_at)
 
       controller.response.last_modified ||= timestamp if timestamp
 

test/http_cache_responder_test.rb

@@ -86,10 +86,11 @@ def test_does_not_use_cache_if_http_cache_is_false
     assert_equal 200, @response.status
   end
 
-  def test_collection_chooses_the_latest_timestamp
+  def test_does_not_set_cache_for_collection
     get :collection
-    assert_equal Time.utc(2009).httpdate, @response.headers["Last-Modified"]
-    assert_match /xml/, @response.body
+
+    assert_nil @response.headers["Last-Modified"]
+    assert_not_nil @response.headers["ETag"]
     assert_equal 200, @response.status
   end
 
@@ -113,8 +114,8 @@ def test_work_with_an_empty_array
     assert_equal 200, @response.status
   end
 
-  def test_it_does_not_set_body_etag
-    get :collection
+  def test_it_does_not_set_body_etag_for_single_resource
+    get :single
     assert_nil @response.headers["ETag"]
   end