text: // Copyright 2014 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #include "base/file_util.h"
  #include "base/files/scoped_temp_dir.h"
  #include "base/memory/scoped_ptr.h"
  #include "base/message_loop/message_loop.h"
  #include "base/path_service.h"
  #include "chrome/common/chrome_paths.h"
  #include "content/public/test/test_browser_thread.h"
  #include "extensions/browser/value_store/value_store_frontend.h"
  #include "testing/gtest/include/gtest/gtest.h"
  
  using content::BrowserThread;
  
  class ValueStoreFrontendTest : public testing::Test {
   public:
    ValueStoreFrontendTest()
        : ui_thread_(BrowserThread::UI, base::MessageLoop::current()),
          file_thread_(BrowserThread::FILE, base::MessageLoop::current()) {
    }
  
    virtual void SetUp() {
      ASSERT_TRUE(temp_dir_.CreateUniqueTempDir());
  
      base::FilePath test_data_dir;
      ASSERT_TRUE(PathService::Get(chrome::DIR_TEST_DATA, &test_data_dir));
      base::FilePath src_db(test_data_dir.AppendASCII("value_store_db"));
      db_path_ = temp_dir_.path().AppendASCII("temp_db");
      base::CopyDirectory(src_db, db_path_, true);
  
      ResetStorage();
    }
  
    virtual void TearDown() {
      base::MessageLoop::current()->RunUntilIdle();  // wait for storage to delete
      storage_.reset();
    }
  
    // Reset the value store, reloading the DB from disk.
    void ResetStorage() {
      storage_.reset(new ValueStoreFrontend(db_path_));
    }
  
    bool Get(const std::string& key, scoped_ptr<base::Value>* output) {
      storage_->Get(key, base::Bind(&ValueStoreFrontendTest::GetAndWait,
                                    base::Unretained(this), output));
      base::MessageLoop::current()->Run();  // wait for GetAndWait
      return !!output->get();
    }
  
   protected:
    void GetAndWait(scoped_ptr<base::Value>* output,
                    scoped_ptr<base::Value> result) {
      *output = result.Pass();
      base::MessageLoop::current()->Quit();
    }
  
    scoped_ptr<ValueStoreFrontend> storage_;
    base::ScopedTempDir temp_dir_;
    base::FilePath db_path_;
    base::MessageLoop message_loop_;
    content::TestBrowserThread ui_thread_;
    content::TestBrowserThread file_thread_;
  };
  
  TEST_F(ValueStoreFrontendTest, GetExistingData) {
    scoped_ptr<base::Value> value;
    ASSERT_FALSE(Get("key0", &value));
  
    // Test existing keys in the DB.
    {
      ASSERT_TRUE(Get("key1", &value));
      std::string result;
      ASSERT_TRUE(value->GetAsString(&result));
      EXPECT_EQ("value1", result);
    }
  
    {
      ASSERT_TRUE(Get("key2", &value));
      int result;
      ASSERT_TRUE(value->GetAsInteger(&result));
      EXPECT_EQ(2, result);
    }
  }
  
  TEST_F(ValueStoreFrontendTest, ChangesPersistAfterReload) {
    storage_->Set("key0",
        scoped_ptr<base::Value>(base::Value::CreateIntegerValue(0)));
    storage_->Set("key1", scoped_ptr<base::Value>(new base::StringValue("new1")));
    storage_->Remove("key2");
  
    // Reload the DB and test our changes.
    ResetStorage();
  
    scoped_ptr<base::Value> value;
    {
      ASSERT_TRUE(Get("key0", &value));
      int result;
      ASSERT_TRUE(value->GetAsInteger(&result));
      EXPECT_EQ(0, result);
    }
  
    {
      ASSERT_TRUE(Get("key1", &value));
      std::string result;
      ASSERT_TRUE(value->GetAsString(&result));
      EXPECT_EQ("new1", result);
    }
  
    ASSERT_FALSE(Get("key2", &value));
  }
  