common/prefs_unittest.cc - android_system_update_engine - Gitiles

 //
 // Copyright (C) 2012 The Android Open Source Project
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //      http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 //

 #include "update_engine/common/prefs.h"

 #include <inttypes.h>

 #include <string>

 #include <base/files/file_util.h>
 #include <base/macros.h>
 #include <base/strings/string_util.h>
 #include <base/strings/stringprintf.h>
 #include <gmock/gmock.h>
 #include <gtest/gtest.h>

 using std::string;
 using testing::Eq;
 using testing::_;

 namespace {
 // Test key used along the tests.
 const char kKey[] = "test-key";
 }

 namespace chromeos_update_engine {

 class PrefsTest : public ::testing::Test {
  protected:
   void SetUp() override {
     ASSERT_TRUE(base::CreateNewTempDirectory("auprefs", &prefs_dir_));
     ASSERT_TRUE(prefs_.Init(prefs_dir_));
   }

   void TearDown() override {
     base::DeleteFile(prefs_dir_, true);  // recursive
   }

   bool SetValue(const string& key, const string& value) {
     return base::WriteFile(prefs_dir_.Append(key), value.data(),
                            value.length()) == static_cast<int>(value.length());
   }

   base::FilePath prefs_dir_;
   Prefs prefs_;
 };

 TEST_F(PrefsTest, GetFileNameForKey) {
   const char kAllvalidCharsKey[] =
       "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_-";
   base::FilePath path;
   EXPECT_TRUE(prefs_.GetFileNameForKey(kAllvalidCharsKey, &path));
   EXPECT_EQ(prefs_dir_.Append(kAllvalidCharsKey).value(), path.value());
 }

 TEST_F(PrefsTest, GetFileNameForKeyBadCharacter) {
   base::FilePath path;
   EXPECT_FALSE(prefs_.GetFileNameForKey("ABC abc", &path));
 }

 TEST_F(PrefsTest, GetFileNameForKeyEmpty) {
   base::FilePath path;
   EXPECT_FALSE(prefs_.GetFileNameForKey("", &path));
 }

 TEST_F(PrefsTest, GetString) {
   const string test_data = "test data";
   ASSERT_TRUE(SetValue(kKey, test_data));
   string value;
   EXPECT_TRUE(prefs_.GetString(kKey, &value));
   EXPECT_EQ(test_data, value);
 }

 TEST_F(PrefsTest, GetStringBadKey) {
   string value;
   EXPECT_FALSE(prefs_.GetString(",bad", &value));
 }

 TEST_F(PrefsTest, GetStringNonExistentKey) {
   string value;
   EXPECT_FALSE(prefs_.GetString("non-existent-key", &value));
 }

 TEST_F(PrefsTest, SetString) {
   const char kValue[] = "some test value\non 2 lines";
   EXPECT_TRUE(prefs_.SetString(kKey, kValue));
   string value;
   EXPECT_TRUE(base::ReadFileToString(prefs_dir_.Append(kKey), &value));
   EXPECT_EQ(kValue, value);
 }

 TEST_F(PrefsTest, SetStringBadKey) {
   const char kKeyWithDots[] = ".no-dots";
   EXPECT_FALSE(prefs_.SetString(kKeyWithDots, "some value"));
   EXPECT_FALSE(base::PathExists(prefs_dir_.Append(kKeyWithDots)));
 }

 TEST_F(PrefsTest, SetStringCreateDir) {
   const char kValue[] = "test value";
   base::FilePath subdir = prefs_dir_.Append("subdir1").Append("subdir2");
   EXPECT_TRUE(prefs_.Init(subdir));
   EXPECT_TRUE(prefs_.SetString(kKey, kValue));
   string value;
   EXPECT_TRUE(base::ReadFileToString(subdir.Append(kKey), &value));
   EXPECT_EQ(kValue, value);
 }

 TEST_F(PrefsTest, SetStringDirCreationFailure) {
   EXPECT_TRUE(prefs_.Init(base::FilePath("/dev/null")));
   EXPECT_FALSE(prefs_.SetString(kKey, "test value"));
 }

 TEST_F(PrefsTest, SetStringFileCreationFailure) {
   base::CreateDirectory(prefs_dir_.Append(kKey));
   EXPECT_FALSE(prefs_.SetString(kKey, "test value"));
   EXPECT_TRUE(base::DirectoryExists(prefs_dir_.Append(kKey)));
 }

 TEST_F(PrefsTest, GetInt64) {
   ASSERT_TRUE(SetValue(kKey, " \n 25 \t "));
   int64_t value;
   EXPECT_TRUE(prefs_.GetInt64(kKey, &value));
   EXPECT_EQ(25, value);
 }

 TEST_F(PrefsTest, GetInt64BadValue) {
   ASSERT_TRUE(SetValue(kKey, "30a"));
   int64_t value;
   EXPECT_FALSE(prefs_.GetInt64(kKey, &value));
 }

 TEST_F(PrefsTest, GetInt64Max) {
   ASSERT_TRUE(SetValue(kKey, base::StringPrintf(
       "%" PRIi64, std::numeric_limits<int64_t>::max())));
   int64_t value;
   EXPECT_TRUE(prefs_.GetInt64(kKey, &value));
   EXPECT_EQ(std::numeric_limits<int64_t>::max(), value);
 }

 TEST_F(PrefsTest, GetInt64Min) {
   ASSERT_TRUE(SetValue(kKey, base::StringPrintf(
         "%" PRIi64, std::numeric_limits<int64_t>::min())));
   int64_t value;
   EXPECT_TRUE(prefs_.GetInt64(kKey, &value));
   EXPECT_EQ(std::numeric_limits<int64_t>::min(), value);
 }

 TEST_F(PrefsTest, GetInt64Negative) {
   ASSERT_TRUE(SetValue(kKey, " \t -100 \n "));
   int64_t value;
   EXPECT_TRUE(prefs_.GetInt64(kKey, &value));
   EXPECT_EQ(-100, value);
 }

 TEST_F(PrefsTest, GetInt64NonExistentKey) {
   int64_t value;
   EXPECT_FALSE(prefs_.GetInt64("random-key", &value));
 }

 TEST_F(PrefsTest, SetInt64) {
   EXPECT_TRUE(prefs_.SetInt64(kKey, -123));
   string value;
   EXPECT_TRUE(base::ReadFileToString(prefs_dir_.Append(kKey), &value));
   EXPECT_EQ("-123", value);
 }

 TEST_F(PrefsTest, SetInt64BadKey) {
   const char kKeyWithSpaces[] = "s p a c e s";
   EXPECT_FALSE(prefs_.SetInt64(kKeyWithSpaces, 20));
   EXPECT_FALSE(base::PathExists(prefs_dir_.Append(kKeyWithSpaces)));
 }

 TEST_F(PrefsTest, SetInt64Max) {
   EXPECT_TRUE(prefs_.SetInt64(kKey, std::numeric_limits<int64_t>::max()));
   string value;
   EXPECT_TRUE(base::ReadFileToString(prefs_dir_.Append(kKey), &value));
   EXPECT_EQ(base::StringPrintf("%" PRIi64, std::numeric_limits<int64_t>::max()),
             value);
 }

 TEST_F(PrefsTest, SetInt64Min) {
   EXPECT_TRUE(prefs_.SetInt64(kKey, std::numeric_limits<int64_t>::min()));
   string value;
   EXPECT_TRUE(base::ReadFileToString(prefs_dir_.Append(kKey), &value));
   EXPECT_EQ(base::StringPrintf("%" PRIi64, std::numeric_limits<int64_t>::min()),
             value);
 }

 TEST_F(PrefsTest, GetBooleanFalse) {
   ASSERT_TRUE(SetValue(kKey, " \n false \t "));
   bool value;
   EXPECT_TRUE(prefs_.GetBoolean(kKey, &value));
   EXPECT_FALSE(value);
 }

 TEST_F(PrefsTest, GetBooleanTrue) {
   const char kKey[] = "test-key";
   ASSERT_TRUE(SetValue(kKey, " \t true \n "));
   bool value;
   EXPECT_TRUE(prefs_.GetBoolean(kKey, &value));
   EXPECT_TRUE(value);
 }

 TEST_F(PrefsTest, GetBooleanBadValue) {
   const char kKey[] = "test-key";
   ASSERT_TRUE(SetValue(kKey, "1"));
   bool value;
   EXPECT_FALSE(prefs_.GetBoolean(kKey, &value));
 }

 TEST_F(PrefsTest, GetBooleanBadEmptyValue) {
   const char kKey[] = "test-key";
   ASSERT_TRUE(SetValue(kKey, ""));
   bool value;
   EXPECT_FALSE(prefs_.GetBoolean(kKey, &value));
 }

 TEST_F(PrefsTest, GetBooleanNonExistentKey) {
   bool value;
   EXPECT_FALSE(prefs_.GetBoolean("random-key", &value));
 }

 TEST_F(PrefsTest, SetBooleanTrue) {
   const char kKey[] = "test-bool";
   EXPECT_TRUE(prefs_.SetBoolean(kKey, true));
   string value;
   EXPECT_TRUE(base::ReadFileToString(prefs_dir_.Append(kKey), &value));
   EXPECT_EQ("true", value);
 }

 TEST_F(PrefsTest, SetBooleanFalse) {
   const char kKey[] = "test-bool";
   EXPECT_TRUE(prefs_.SetBoolean(kKey, false));
   string value;
   EXPECT_TRUE(base::ReadFileToString(prefs_dir_.Append(kKey), &value));
   EXPECT_EQ("false", value);
 }

 TEST_F(PrefsTest, SetBooleanBadKey) {
   const char kKey[] = "s p a c e s";
   EXPECT_FALSE(prefs_.SetBoolean(kKey, true));
   EXPECT_FALSE(base::PathExists(prefs_dir_.Append(kKey)));
 }

 TEST_F(PrefsTest, ExistsWorks) {
   // test that the key doesn't exist before we set it.
   EXPECT_FALSE(prefs_.Exists(kKey));

   // test that the key exists after we set it.
   ASSERT_TRUE(prefs_.SetInt64(kKey, 8));
   EXPECT_TRUE(prefs_.Exists(kKey));
 }

 TEST_F(PrefsTest, DeleteWorks) {
   // test that it's alright to delete a non-existent key.
   EXPECT_TRUE(prefs_.Delete(kKey));

   // delete the key after we set it.
   ASSERT_TRUE(prefs_.SetInt64(kKey, 0));
   EXPECT_TRUE(prefs_.Delete(kKey));

   // make sure it doesn't exist anymore.
   EXPECT_FALSE(prefs_.Exists(kKey));
 }

 class MockPrefsObserver : public PrefsInterface::ObserverInterface {
  public:
   MOCK_METHOD1(OnPrefSet, void(const string&));
   MOCK_METHOD1(OnPrefDeleted, void(const string& key));
 };

 TEST_F(PrefsTest, ObserversCalled) {
   MockPrefsObserver mock_obserser;
   prefs_.AddObserver(kKey, &mock_obserser);

   EXPECT_CALL(mock_obserser, OnPrefSet(Eq(kKey)));
   EXPECT_CALL(mock_obserser, OnPrefDeleted(_)).Times(0);
   prefs_.SetString(kKey, "value");
   testing::Mock::VerifyAndClearExpectations(&mock_obserser);

   EXPECT_CALL(mock_obserser, OnPrefSet(_)).Times(0);
   EXPECT_CALL(mock_obserser, OnPrefDeleted(Eq(kKey)));
   prefs_.Delete(kKey);
   testing::Mock::VerifyAndClearExpectations(&mock_obserser);

   prefs_.RemoveObserver(kKey, &mock_obserser);
 }

 TEST_F(PrefsTest, OnlyCalledOnObservedKeys) {
   MockPrefsObserver mock_obserser;
   const char kUnusedKey[] = "unused-key";
   prefs_.AddObserver(kUnusedKey, &mock_obserser);

   EXPECT_CALL(mock_obserser, OnPrefSet(_)).Times(0);
   EXPECT_CALL(mock_obserser, OnPrefDeleted(_)).Times(0);
   prefs_.SetString(kKey, "value");
   prefs_.Delete(kKey);

   prefs_.RemoveObserver(kUnusedKey, &mock_obserser);
 }

 TEST_F(PrefsTest, RemovedObserversNotCalled) {
   MockPrefsObserver mock_obserser_a, mock_obserser_b;
   prefs_.AddObserver(kKey, &mock_obserser_a);
   prefs_.AddObserver(kKey, &mock_obserser_b);
   EXPECT_CALL(mock_obserser_a, OnPrefSet(_)).Times(2);
   EXPECT_CALL(mock_obserser_b, OnPrefSet(_)).Times(1);
   EXPECT_TRUE(prefs_.SetString(kKey, "value"));
   prefs_.RemoveObserver(kKey, &mock_obserser_b);
   EXPECT_TRUE(prefs_.SetString(kKey, "other value"));
   prefs_.RemoveObserver(kKey, &mock_obserser_a);
   EXPECT_TRUE(prefs_.SetString(kKey, "yet another value"));
 }

 TEST_F(PrefsTest, UnsuccessfulCallsNotObserved) {
   MockPrefsObserver mock_obserser;
   const char kInvalidKey[] = "no spaces or .";
   prefs_.AddObserver(kInvalidKey, &mock_obserser);

   EXPECT_CALL(mock_obserser, OnPrefSet(_)).Times(0);
   EXPECT_CALL(mock_obserser, OnPrefDeleted(_)).Times(0);
   EXPECT_FALSE(prefs_.SetString(kInvalidKey, "value"));
   EXPECT_FALSE(prefs_.Delete(kInvalidKey));

   prefs_.RemoveObserver(kInvalidKey, &mock_obserser);
 }

 }  // namespace chromeos_update_engine
	//
	// Copyright (C) 2012 The Android Open Source Project
	//
	// Licensed under the Apache License, Version 2.0 (the "License");
	// you may not use this file except in compliance with the License.
	// You may obtain a copy of the License at
	//
	// http://www.apache.org/licenses/LICENSE-2.0
	//
	// Unless required by applicable law or agreed to in writing, software
	// distributed under the License is distributed on an "AS IS" BASIS,
	// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	// See the License for the specific language governing permissions and
	// limitations under the License.
	//

	#include "update_engine/common/prefs.h"

	#include <inttypes.h>

	#include <string>

	#include <base/files/file_util.h>
	#include <base/macros.h>
	#include <base/strings/string_util.h>
	#include <base/strings/stringprintf.h>
	#include <gmock/gmock.h>
	#include <gtest/gtest.h>

	using std::string;
	using testing::Eq;
	using testing::_;

	namespace {
	// Test key used along the tests.
	const char kKey[] = "test-key";
	}

	namespace chromeos_update_engine {

	class PrefsTest : public ::testing::Test {
	protected:
	void SetUp() override {
	ASSERT_TRUE(base::CreateNewTempDirectory("auprefs", &prefs_dir_));
	ASSERT_TRUE(prefs_.Init(prefs_dir_));
	}

	void TearDown() override {
	base::DeleteFile(prefs_dir_, true); // recursive
	}

	bool SetValue(const string& key, const string& value) {
	return base::WriteFile(prefs_dir_.Append(key), value.data(),
	value.length()) == static_cast<int>(value.length());
	}

	base::FilePath prefs_dir_;
	Prefs prefs_;
	};

	TEST_F(PrefsTest, GetFileNameForKey) {
	const char kAllvalidCharsKey[] =
	"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_-";
	base::FilePath path;
	EXPECT_TRUE(prefs_.GetFileNameForKey(kAllvalidCharsKey, &path));
	EXPECT_EQ(prefs_dir_.Append(kAllvalidCharsKey).value(), path.value());
	}

	TEST_F(PrefsTest, GetFileNameForKeyBadCharacter) {
	base::FilePath path;
	EXPECT_FALSE(prefs_.GetFileNameForKey("ABC abc", &path));
	}

	TEST_F(PrefsTest, GetFileNameForKeyEmpty) {
	base::FilePath path;
	EXPECT_FALSE(prefs_.GetFileNameForKey("", &path));
	}

	TEST_F(PrefsTest, GetString) {
	const string test_data = "test data";
	ASSERT_TRUE(SetValue(kKey, test_data));
	string value;
	EXPECT_TRUE(prefs_.GetString(kKey, &value));
	EXPECT_EQ(test_data, value);
	}

	TEST_F(PrefsTest, GetStringBadKey) {
	string value;
	EXPECT_FALSE(prefs_.GetString(",bad", &value));
	}

	TEST_F(PrefsTest, GetStringNonExistentKey) {
	string value;
	EXPECT_FALSE(prefs_.GetString("non-existent-key", &value));
	}

	TEST_F(PrefsTest, SetString) {
	const char kValue[] = "some test value\non 2 lines";
	EXPECT_TRUE(prefs_.SetString(kKey, kValue));
	string value;
	EXPECT_TRUE(base::ReadFileToString(prefs_dir_.Append(kKey), &value));
	EXPECT_EQ(kValue, value);
	}

	TEST_F(PrefsTest, SetStringBadKey) {
	const char kKeyWithDots[] = ".no-dots";
	EXPECT_FALSE(prefs_.SetString(kKeyWithDots, "some value"));
	EXPECT_FALSE(base::PathExists(prefs_dir_.Append(kKeyWithDots)));
	}

	TEST_F(PrefsTest, SetStringCreateDir) {
	const char kValue[] = "test value";
	base::FilePath subdir = prefs_dir_.Append("subdir1").Append("subdir2");
	EXPECT_TRUE(prefs_.Init(subdir));
	EXPECT_TRUE(prefs_.SetString(kKey, kValue));
	string value;
	EXPECT_TRUE(base::ReadFileToString(subdir.Append(kKey), &value));
	EXPECT_EQ(kValue, value);
	}

	TEST_F(PrefsTest, SetStringDirCreationFailure) {
	EXPECT_TRUE(prefs_.Init(base::FilePath("/dev/null")));
	EXPECT_FALSE(prefs_.SetString(kKey, "test value"));
	}

	TEST_F(PrefsTest, SetStringFileCreationFailure) {
	base::CreateDirectory(prefs_dir_.Append(kKey));
	EXPECT_FALSE(prefs_.SetString(kKey, "test value"));
	EXPECT_TRUE(base::DirectoryExists(prefs_dir_.Append(kKey)));
	}

	TEST_F(PrefsTest, GetInt64) {
	ASSERT_TRUE(SetValue(kKey, " \n 25 \t "));
	int64_t value;
	EXPECT_TRUE(prefs_.GetInt64(kKey, &value));
	EXPECT_EQ(25, value);
	}

	TEST_F(PrefsTest, GetInt64BadValue) {
	ASSERT_TRUE(SetValue(kKey, "30a"));
	int64_t value;
	EXPECT_FALSE(prefs_.GetInt64(kKey, &value));
	}

	TEST_F(PrefsTest, GetInt64Max) {
	ASSERT_TRUE(SetValue(kKey, base::StringPrintf(
	"%" PRIi64, std::numeric_limits<int64_t>::max())));
	int64_t value;
	EXPECT_TRUE(prefs_.GetInt64(kKey, &value));
	EXPECT_EQ(std::numeric_limits<int64_t>::max(), value);
	}

	TEST_F(PrefsTest, GetInt64Min) {
	ASSERT_TRUE(SetValue(kKey, base::StringPrintf(
	"%" PRIi64, std::numeric_limits<int64_t>::min())));
	int64_t value;
	EXPECT_TRUE(prefs_.GetInt64(kKey, &value));
	EXPECT_EQ(std::numeric_limits<int64_t>::min(), value);
	}

	TEST_F(PrefsTest, GetInt64Negative) {
	ASSERT_TRUE(SetValue(kKey, " \t -100 \n "));
	int64_t value;
	EXPECT_TRUE(prefs_.GetInt64(kKey, &value));
	EXPECT_EQ(-100, value);
	}

	TEST_F(PrefsTest, GetInt64NonExistentKey) {
	int64_t value;
	EXPECT_FALSE(prefs_.GetInt64("random-key", &value));
	}

	TEST_F(PrefsTest, SetInt64) {
	EXPECT_TRUE(prefs_.SetInt64(kKey, -123));
	string value;
	EXPECT_TRUE(base::ReadFileToString(prefs_dir_.Append(kKey), &value));
	EXPECT_EQ("-123", value);
	}

	TEST_F(PrefsTest, SetInt64BadKey) {
	const char kKeyWithSpaces[] = "s p a c e s";
	EXPECT_FALSE(prefs_.SetInt64(kKeyWithSpaces, 20));
	EXPECT_FALSE(base::PathExists(prefs_dir_.Append(kKeyWithSpaces)));
	}

	TEST_F(PrefsTest, SetInt64Max) {
	EXPECT_TRUE(prefs_.SetInt64(kKey, std::numeric_limits<int64_t>::max()));
	string value;
	EXPECT_TRUE(base::ReadFileToString(prefs_dir_.Append(kKey), &value));
	EXPECT_EQ(base::StringPrintf("%" PRIi64, std::numeric_limits<int64_t>::max()),
	value);
	}

	TEST_F(PrefsTest, SetInt64Min) {
	EXPECT_TRUE(prefs_.SetInt64(kKey, std::numeric_limits<int64_t>::min()));
	string value;
	EXPECT_TRUE(base::ReadFileToString(prefs_dir_.Append(kKey), &value));
	EXPECT_EQ(base::StringPrintf("%" PRIi64, std::numeric_limits<int64_t>::min()),
	value);
	}

	TEST_F(PrefsTest, GetBooleanFalse) {
	ASSERT_TRUE(SetValue(kKey, " \n false \t "));
	bool value;
	EXPECT_TRUE(prefs_.GetBoolean(kKey, &value));
	EXPECT_FALSE(value);
	}

	TEST_F(PrefsTest, GetBooleanTrue) {
	const char kKey[] = "test-key";
	ASSERT_TRUE(SetValue(kKey, " \t true \n "));
	bool value;
	EXPECT_TRUE(prefs_.GetBoolean(kKey, &value));
	EXPECT_TRUE(value);
	}

	TEST_F(PrefsTest, GetBooleanBadValue) {
	const char kKey[] = "test-key";
	ASSERT_TRUE(SetValue(kKey, "1"));
	bool value;
	EXPECT_FALSE(prefs_.GetBoolean(kKey, &value));
	}

	TEST_F(PrefsTest, GetBooleanBadEmptyValue) {
	const char kKey[] = "test-key";
	ASSERT_TRUE(SetValue(kKey, ""));
	bool value;
	EXPECT_FALSE(prefs_.GetBoolean(kKey, &value));
	}

	TEST_F(PrefsTest, GetBooleanNonExistentKey) {
	bool value;
	EXPECT_FALSE(prefs_.GetBoolean("random-key", &value));
	}

	TEST_F(PrefsTest, SetBooleanTrue) {
	const char kKey[] = "test-bool";
	EXPECT_TRUE(prefs_.SetBoolean(kKey, true));
	string value;
	EXPECT_TRUE(base::ReadFileToString(prefs_dir_.Append(kKey), &value));
	EXPECT_EQ("true", value);
	}

	TEST_F(PrefsTest, SetBooleanFalse) {
	const char kKey[] = "test-bool";
	EXPECT_TRUE(prefs_.SetBoolean(kKey, false));
	string value;
	EXPECT_TRUE(base::ReadFileToString(prefs_dir_.Append(kKey), &value));
	EXPECT_EQ("false", value);
	}

	TEST_F(PrefsTest, SetBooleanBadKey) {
	const char kKey[] = "s p a c e s";
	EXPECT_FALSE(prefs_.SetBoolean(kKey, true));
	EXPECT_FALSE(base::PathExists(prefs_dir_.Append(kKey)));
	}

	TEST_F(PrefsTest, ExistsWorks) {
	// test that the key doesn't exist before we set it.
	EXPECT_FALSE(prefs_.Exists(kKey));

	// test that the key exists after we set it.
	ASSERT_TRUE(prefs_.SetInt64(kKey, 8));
	EXPECT_TRUE(prefs_.Exists(kKey));
	}

	TEST_F(PrefsTest, DeleteWorks) {
	// test that it's alright to delete a non-existent key.
	EXPECT_TRUE(prefs_.Delete(kKey));

	// delete the key after we set it.
	ASSERT_TRUE(prefs_.SetInt64(kKey, 0));
	EXPECT_TRUE(prefs_.Delete(kKey));

	// make sure it doesn't exist anymore.
	EXPECT_FALSE(prefs_.Exists(kKey));
	}

	class MockPrefsObserver : public PrefsInterface::ObserverInterface {
	public:
	MOCK_METHOD1(OnPrefSet, void(const string&));
	MOCK_METHOD1(OnPrefDeleted, void(const string& key));
	};

	TEST_F(PrefsTest, ObserversCalled) {
	MockPrefsObserver mock_obserser;
	prefs_.AddObserver(kKey, &mock_obserser);

	EXPECT_CALL(mock_obserser, OnPrefSet(Eq(kKey)));
	EXPECT_CALL(mock_obserser, OnPrefDeleted(_)).Times(0);
	prefs_.SetString(kKey, "value");
	testing::Mock::VerifyAndClearExpectations(&mock_obserser);

	EXPECT_CALL(mock_obserser, OnPrefSet(_)).Times(0);
	EXPECT_CALL(mock_obserser, OnPrefDeleted(Eq(kKey)));
	prefs_.Delete(kKey);
	testing::Mock::VerifyAndClearExpectations(&mock_obserser);

	prefs_.RemoveObserver(kKey, &mock_obserser);
	}

	TEST_F(PrefsTest, OnlyCalledOnObservedKeys) {
	MockPrefsObserver mock_obserser;
	const char kUnusedKey[] = "unused-key";
	prefs_.AddObserver(kUnusedKey, &mock_obserser);

	EXPECT_CALL(mock_obserser, OnPrefSet(_)).Times(0);
	EXPECT_CALL(mock_obserser, OnPrefDeleted(_)).Times(0);
	prefs_.SetString(kKey, "value");
	prefs_.Delete(kKey);

	prefs_.RemoveObserver(kUnusedKey, &mock_obserser);
	}

	TEST_F(PrefsTest, RemovedObserversNotCalled) {
	MockPrefsObserver mock_obserser_a, mock_obserser_b;
	prefs_.AddObserver(kKey, &mock_obserser_a);
	prefs_.AddObserver(kKey, &mock_obserser_b);
	EXPECT_CALL(mock_obserser_a, OnPrefSet(_)).Times(2);
	EXPECT_CALL(mock_obserser_b, OnPrefSet(_)).Times(1);
	EXPECT_TRUE(prefs_.SetString(kKey, "value"));
	prefs_.RemoveObserver(kKey, &mock_obserser_b);
	EXPECT_TRUE(prefs_.SetString(kKey, "other value"));
	prefs_.RemoveObserver(kKey, &mock_obserser_a);
	EXPECT_TRUE(prefs_.SetString(kKey, "yet another value"));
	}

	TEST_F(PrefsTest, UnsuccessfulCallsNotObserved) {
	MockPrefsObserver mock_obserser;
	const char kInvalidKey[] = "no spaces or .";
	prefs_.AddObserver(kInvalidKey, &mock_obserser);

	EXPECT_CALL(mock_obserser, OnPrefSet(_)).Times(0);
	EXPECT_CALL(mock_obserser, OnPrefDeleted(_)).Times(0);
	EXPECT_FALSE(prefs_.SetString(kInvalidKey, "value"));
	EXPECT_FALSE(prefs_.Delete(kInvalidKey));

	prefs_.RemoveObserver(kInvalidKey, &mock_obserser);
	}

	} // namespace chromeos_update_engine