diff --git a/buffet/commands/cloud_command_proxy.cc b/buffet/commands/cloud_command_proxy.cc
index d3cd5a6..341401e 100644
--- a/buffet/commands/cloud_command_proxy.cc
+++ b/buffet/commands/cloud_command_proxy.cc
@@ -22,7 +22,7 @@
 void CloudCommandProxy::OnResultsChanged(const native_types::Object& results) {
   base::DictionaryValue patch;
   patch.Set(commands::attributes::kCommand_Results,
-            TypedValueToJson(results, nullptr).get());
+            TypedValueToJson(results, nullptr).release());
   device_registration_info_->UpdateCommand(command_instance_->GetID(), patch);
 }
 
diff --git a/buffet/commands/command_manager.cc b/buffet/commands/command_manager.cc
index afdd518..f7533ca 100644
--- a/buffet/commands/command_manager.cc
+++ b/buffet/commands/command_manager.cc
@@ -26,6 +26,10 @@
   command_queue_.SetCommandDispachInterface(&command_dispatcher_);
 }
 
+CommandManager::CommandManager(CommandDispachInterface* dispatch_interface) {
+  command_queue_.SetCommandDispachInterface(dispatch_interface);
+}
+
 const CommandDictionary& CommandManager::GetCommandDictionary() const {
   return dictionary_;
 }
diff --git a/buffet/commands/command_manager.h b/buffet/commands/command_manager.h
index 8088e26..a703ab3 100644
--- a/buffet/commands/command_manager.h
+++ b/buffet/commands/command_manager.h
@@ -36,6 +36,8 @@
   explicit CommandManager(
       const base::WeakPtr<chromeos::dbus_utils::ExportedObjectManager>&
           object_manager);
+  // Special constructor to help mock out command dispatcher for testing.
+  explicit CommandManager(CommandDispachInterface* dispatch_interface);
 
   // Sets callback which is called when command definitions is changed.
   void SetOnCommandDefChanged(const base::Closure& on_command_defs_changed) {
diff --git a/buffet/device_registration_info_unittest.cc b/buffet/device_registration_info_unittest.cc
index 91dc8b1..6136eeb 100644
--- a/buffet/device_registration_info_unittest.cc
+++ b/buffet/device_registration_info_unittest.cc
@@ -5,6 +5,7 @@
 #include "buffet/device_registration_info.h"
 
 #include <base/json/json_reader.h>
+#include <base/json/json_writer.h>
 #include <base/values.h>
 #include <chromeos/bind_lambda.h>
 #include <chromeos/http/http_request.h>
@@ -179,6 +180,10 @@
   static bool Save(DeviceRegistrationInfo* info) {
     return info->Save();
   }
+  static void PublishCommands(DeviceRegistrationInfo* info,
+                              const base::ListValue& commands) {
+    return info->PublishCommands(commands);
+  }
 };
 
 class DeviceRegistrationInfoTest : public ::testing::Test {
@@ -188,7 +193,7 @@
     storage_ = std::make_shared<MemStorage>();
     storage_->Save(&data_);
     transport_ = std::make_shared<chromeos::http::fake::Transport>();
-    command_manager_ = std::make_shared<CommandManager>();
+    command_manager_ = std::make_shared<CommandManager>(nullptr);
     state_manager_ = std::make_shared<StateManager>(&mock_state_change_queue_);
     chromeos::KeyValueStore config_store;
     config_store.SetString("client_id", test_data::kClientId);
@@ -213,6 +218,8 @@
                                    transport_, storage_,
                                    true,
                                    mock_callback));
+    EXPECT_CALL(*this, OnRegistrationStatusChange())
+        .Times(testing::AnyNumber());
   }
 
   MOCK_METHOD0(OnRegistrationStatusChange, void());
@@ -503,4 +510,52 @@
   EXPECT_EQ(RegistrationStatus::kConnecting, dev_reg_->GetRegistrationStatus());
 }
 
+TEST_F(DeviceRegistrationInfoTest, UpdateCommand) {
+  EXPECT_TRUE(dev_reg_->Load());
+  auto json_cmds = buffet::unittests::CreateDictionaryValue(R"({
+    'robot': {
+      '_jump': {
+        'parameters': {'_height': 'integer'},
+        'results': {'status': 'string'}
+      }
+    }
+  })");
+  EXPECT_TRUE(command_manager_->LoadCommands(*json_cmds, "", nullptr));
+
+  auto commands_json = buffet::unittests::CreateValue(R"([{
+    'name':'robot._jump',
+    'id':'1234',
+    'parameters': {'_height': 100}
+  }])");
+  ASSERT_NE(nullptr, commands_json.get());
+  const base::ListValue* command_list = nullptr;
+  ASSERT_TRUE(commands_json->GetAsList(&command_list));
+  DeviceRegistrationInfo::TestHelper::PublishCommands(dev_reg_.get(),
+                                                      *command_list);
+  auto command = command_manager_->FindCommand("1234");
+  ASSERT_NE(nullptr, command);
+  StringPropType string_type;
+  native_types::Object results{
+    {"status", string_type.CreateValue(std::string{"Ok"}, nullptr)}
+  };
+
+  auto update_command = [](const ServerRequest& request,
+                           ServerResponse* response) {
+    // Make sure we serialize the JSON back without any pretty print so
+    // the string comparison works correctly.
+    auto json = request.GetDataAsJson();
+    EXPECT_NE(nullptr, json.get());
+    std::string value;
+    ASSERT_TRUE(base::JSONWriter::Write(json.get(), &value));
+    EXPECT_EQ(R"({"results":{"status":"Ok"}})", value);
+  };
+
+  transport_->AddHandler(dev_reg_->GetServiceURL("commands/1234"),
+      chromeos::http::request_type::kPatch,
+      base::Bind(update_command));
+
+  command->SetResults(results);
+}
+
+
 }  // namespace buffet
diff --git a/buffet/utils.cc b/buffet/utils.cc
index 9cd7271..8e29ebe 100644
--- a/buffet/utils.cc
+++ b/buffet/utils.cc
@@ -20,7 +20,6 @@
 
 std::unique_ptr<const base::DictionaryValue> LoadJsonDict(
     const base::FilePath& json_file_path, chromeos::ErrorPtr* error) {
-  std::unique_ptr<const base::DictionaryValue> result;
   std::string json_string;
   if (!base::ReadFileToString(json_file_path, &json_string)) {
     chromeos::errors::system::AddSystemError(error, FROM_HERE, errno);
@@ -28,8 +27,14 @@
                                  kFileReadError,
                                  "Failed to read file '%s'",
                                  json_file_path.value().c_str());
-    return result;
+    return {};
   }
+  return LoadJsonDict(json_string, error);
+}
+
+std::unique_ptr<const base::DictionaryValue> LoadJsonDict(
+    const std::string& json_string, chromeos::ErrorPtr* error) {
+  std::unique_ptr<const base::DictionaryValue> result;
   std::string error_message;
   base::Value* value = base::JSONReader::ReadAndReturnError(
       json_string, base::JSON_PARSE_RFC, nullptr, &error_message);
@@ -37,8 +42,8 @@
     chromeos::Error::AddToPrintf(error, FROM_HERE,
                                  chromeos::errors::json::kDomain,
                                  chromeos::errors::json::kParseError,
-                                 "Error parsing content of JSON file '%s': %s",
-                                 json_file_path.value().c_str(),
+                                 "Error parsing JSON string '%s': %s",
+                                 json_string.c_str(),
                                  error_message.c_str());
     return result;
   }
@@ -48,8 +53,8 @@
     chromeos::Error::AddToPrintf(error, FROM_HERE,
                                  chromeos::errors::json::kDomain,
                                  chromeos::errors::json::kObjectExpected,
-                                 "Content of file '%s' is not a JSON object",
-                                 json_file_path.value().c_str());
+                                 "JSON string '%s' is not a JSON object",
+                                 json_string.c_str());
     return result;
   }
   result.reset(dict_value);
diff --git a/buffet/utils.h b/buffet/utils.h
index a776e0c..32738d2 100644
--- a/buffet/utils.h
+++ b/buffet/utils.h
@@ -6,6 +6,7 @@
 #define BUFFET_UTILS_H_
 
 #include <memory>
+#include <string>
 
 #include <base/values.h>
 #include <base/files/file_path.h>
@@ -32,6 +33,10 @@
 std::unique_ptr<const base::DictionaryValue> LoadJsonDict(
     const base::FilePath& json_file_path, chromeos::ErrorPtr* error);
 
+// Helper function to load a JSON dictionary from a string.
+std::unique_ptr<const base::DictionaryValue> LoadJsonDict(
+    const std::string& json_string, chromeos::ErrorPtr* error);
+
 }  // namespace buffet
 
 #endif  // BUFFET_UTILS_H_