Adds async interface method to PersistentPrefStore.

chrome/common/json_pref_store_unittest.cc

Index: chrome/common/json_pref_store_unittest.cc
diff --git a/chrome/common/json_pref_store_unittest.cc b/chrome/common/json_pref_store_unittest.cc
index e7f34f520331b8fb37e80bd874a1874da1ae3da0..d46f4328ac74d92e466e52dd5ee2e8bf26b88a14 100644
--- a/chrome/common/json_pref_store_unittest.cc
+++ b/chrome/common/json_pref_store_unittest.cc
@@ -5,6 +5,7 @@
 #include "base/file_util.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/memory/scoped_temp_dir.h"
 #include "base/message_loop.h"
 #include "base/message_loop_proxy.h"
 #include "base/path_service.h"
@@ -13,12 +14,27 @@
 #include "base/threading/thread.h"
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
-#include "base/memory/scoped_temp_dir.h"
-#include "chrome/common/json_pref_store.h"
 #include "chrome/common/chrome_paths.h"
+#include "chrome/common/json_pref_store.h"
 #include "chrome/common/pref_names.h"
+#include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+namespace {
+
+class MockPrefStoreObserver : public PrefStore::Observer {
+ public:
+  MOCK_METHOD1(OnPrefValueChanged, void (const std::string&));
+  MOCK_METHOD1(OnInitializationCompleted, void (bool));
+};
+
+class MockReadErrorDelegate : public PersistentPrefStore::ReadErrorDelegate {
+ public:
+  MOCK_METHOD1(OnError, void(PersistentPrefStore::PrefReadError));
+};
+
+}  // namespace
+
 class JsonPrefStoreTest : public testing::Test {
  protected:
   virtual void SetUp() {
@@ -70,28 +86,11 @@ TEST_F(JsonPrefStoreTest, InvalidFile) {
                                            moved_aside));
 }
 
-TEST_F(JsonPrefStoreTest, Basic) {
-  ASSERT_TRUE(file_util::CopyFile(data_dir_.AppendASCII("read.json"),
-                                  temp_dir_.path().AppendASCII("write.json")));
-
-  // Test that the persistent value can be loaded.
-  FilePath input_file = temp_dir_.path().AppendASCII("write.json");
-  ASSERT_TRUE(file_util::PathExists(input_file));
-  scoped_refptr<JsonPrefStore> pref_store =
-      new JsonPrefStore(input_file, message_loop_proxy_.get());
-  ASSERT_EQ(PersistentPrefStore::PREF_READ_ERROR_NONE, pref_store->ReadPrefs());
-  ASSERT_FALSE(pref_store->ReadOnly());
-
-  // The JSON file looks like this:
-  // {
-  //   "homepage": "http://www.cnn.com",
-  //   "some_directory": "/usr/local/",
-  //   "tabs": {
-  //     "new_windows_in_tabs": true,
-  //     "max_tabs": 20
-  //   }
-  // }
-
+// This function is used to avoid code duplication while testing synchronous and
+// asynchronous version of the JsonPrefStore loading.
+void RunBasicJsonPrefStoreTest(JsonPrefStore *pref_store,
+                               const FilePath& output_file,
+                               const FilePath& golden_output_file) {
   const char kNewWindowsInTabs[] = "tabs.new_windows_in_tabs";
   const char kMaxTabs[] = "tabs.max_tabs";
   const char kLongIntPref[] = "long_int.pref";
@@ -152,11 +151,96 @@ TEST_F(JsonPrefStoreTest, Basic) {
   EXPECT_EQ(214748364842LL, value);
 
   // Serialize and compare to expected output.
-  FilePath output_file = input_file;
-  FilePath golden_output_file = data_dir_.AppendASCII("write.golden.json");
   ASSERT_TRUE(file_util::PathExists(golden_output_file));
   ASSERT_TRUE(pref_store->WritePrefs());
   MessageLoop::current()->RunAllPending();
   EXPECT_TRUE(file_util::TextContentsEqual(golden_output_file, output_file));
   ASSERT_TRUE(file_util::Delete(output_file, false));
 }
+
+TEST_F(JsonPrefStoreTest, Basic) {
+  ASSERT_TRUE(file_util::CopyFile(data_dir_.AppendASCII("read.json"),
+                                  temp_dir_.path().AppendASCII("write.json")));
+
+  // Test that the persistent value can be loaded.
+  FilePath input_file = temp_dir_.path().AppendASCII("write.json");
+  ASSERT_TRUE(file_util::PathExists(input_file));
+  scoped_refptr<JsonPrefStore> pref_store =
+      new JsonPrefStore(input_file, message_loop_proxy_.get());
+  ASSERT_EQ(PersistentPrefStore::PREF_READ_ERROR_NONE, pref_store->ReadPrefs());
+  ASSERT_FALSE(pref_store->ReadOnly());
+
+  // The JSON file looks like this:
+  // {
+  //   "homepage": "http://www.cnn.com",
+  //   "some_directory": "/usr/local/",
+  //   "tabs": {
+  //     "new_windows_in_tabs": true,
+  //     "max_tabs": 20
+  //   }
+  // }
+
+  RunBasicJsonPrefStoreTest(pref_store,
+                            input_file,
+                            data_dir_.AppendASCII("write.golden.json"));
+}
+
+TEST_F(JsonPrefStoreTest, BasicAsync) {
+  ASSERT_TRUE(file_util::CopyFile(data_dir_.AppendASCII("read.json"),
+                                  temp_dir_.path().AppendASCII("write.json")));
+
+  // Test that the persistent value can be loaded.
+  FilePath input_file = temp_dir_.path().AppendASCII("write.json");
+  ASSERT_TRUE(file_util::PathExists(input_file));
+  scoped_refptr<JsonPrefStore> pref_store =
+      new JsonPrefStore(input_file, message_loop_proxy_.get());
+
+  MockPrefStoreObserver mock_observer;
+  pref_store->AddObserver(&mock_observer);
+
+  MockReadErrorDelegate *mock_error_delegate = new MockReadErrorDelegate;
+  pref_store->ReadPrefsAsync(mock_error_delegate);
+
+  EXPECT_CALL(mock_observer, OnInitializationCompleted(true)).Times(1);
+  EXPECT_CALL(*mock_error_delegate,
+              OnError(PersistentPrefStore::PREF_READ_ERROR_NONE)).Times(0);
+  message_loop_.RunAllPending();
+  pref_store->RemoveObserver(&mock_observer);
+
+  ASSERT_FALSE(pref_store->ReadOnly());
+
+  // The JSON file looks like this:
+  // {
+  //   "homepage": "http://www.cnn.com",
+  //   "some_directory": "/usr/local/",
+  //   "tabs": {
+  //     "new_windows_in_tabs": true,
+  //     "max_tabs": 20
+  //   }
+  // }
+
+  RunBasicJsonPrefStoreTest(pref_store,
+                            input_file,
+                            data_dir_.AppendASCII("write.golden.json"));
+}
+
+// Tests asynchronous reading of the file when there is no file.
+TEST_F(JsonPrefStoreTest, AsyncNonExistingFile) {
+  FilePath bogus_input_file = data_dir_.AppendASCII("read.txt");
+  ASSERT_FALSE(file_util::PathExists(bogus_input_file));
+  scoped_refptr<JsonPrefStore> pref_store =
+      new JsonPrefStore(bogus_input_file, message_loop_proxy_.get());
+  MockPrefStoreObserver mock_observer;
+  pref_store->AddObserver(&mock_observer);
+
+  MockReadErrorDelegate *mock_error_delegate = new MockReadErrorDelegate;
+  pref_store->ReadPrefsAsync(mock_error_delegate);
+
+  EXPECT_CALL(mock_observer, OnInitializationCompleted(true)).Times(1);
+  EXPECT_CALL(*mock_error_delegate,
+              OnError(PersistentPrefStore::PREF_READ_ERROR_NO_FILE)).Times(1);
+  message_loop_.RunAllPending();
+  pref_store->RemoveObserver(&mock_observer);
+
+  EXPECT_FALSE(pref_store->ReadOnly());
+}