AU: Add support for persistent update engine preferences store.

BUG=5140
TEST=emerge-x86-generic, attached unit tests

Review URL: http://codereview.chromium.org/3014035
diff --git a/prefs_unittest.cc b/prefs_unittest.cc
new file mode 100644
index 0000000..fc492fb
--- /dev/null
+++ b/prefs_unittest.cc
@@ -0,0 +1,190 @@
+// Copyright (c) 2010 The Chromium OS 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 <inttypes.h>
+
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/file_util.h"
+#include "base/string_util.h"
+#include "gtest/gtest.h"
+#include "update_engine/prefs.h"
+
+using std::string;
+
+namespace chromeos_update_engine {
+
+class PrefsTest : public ::testing::Test {
+ protected:
+  virtual void SetUp() {
+    ASSERT_TRUE(file_util::CreateNewTempDirectory("auprefs", &prefs_dir_));
+    ASSERT_TRUE(prefs_.Init(prefs_dir_));
+  }
+
+  virtual void TearDown() {
+    file_util::Delete(prefs_dir_, true);  // recursive
+  }
+
+  bool SetValue(const string& key, const string& value) {
+    return file_util::WriteFile(prefs_dir_.Append(key),
+                                value.data(), value.length()) ==
+        static_cast<int>(value.length());
+  }
+
+  FilePath prefs_dir_;
+  Prefs prefs_;
+};
+
+TEST_F(PrefsTest, GetFileNameForKey) {
+  const char kKey[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_-";
+  FilePath path;
+  EXPECT_TRUE(prefs_.GetFileNameForKey(kKey, &path));
+  EXPECT_EQ(prefs_dir_.Append(kKey).value(), path.value());
+}
+
+TEST_F(PrefsTest, GetFileNameForKeyBadCharacter) {
+  FilePath path;
+  EXPECT_FALSE(prefs_.GetFileNameForKey("ABC abc", &path));
+}
+
+TEST_F(PrefsTest, GetFileNameForKeyEmpty) {
+  FilePath path;
+  EXPECT_FALSE(prefs_.GetFileNameForKey("", &path));
+}
+
+TEST_F(PrefsTest, GetString) {
+  const char kKey[] = "test-key";
+  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 kKey[] = "my_test_key";
+  const char kValue[] = "some test value\non 2 lines";
+  EXPECT_TRUE(prefs_.SetString(kKey, kValue));
+  string value;
+  EXPECT_TRUE(file_util::ReadFileToString(prefs_dir_.Append(kKey), &value));
+  EXPECT_EQ(kValue, value);
+}
+
+TEST_F(PrefsTest, SetStringBadKey) {
+  const char kKey[] = ".no-dots";
+  EXPECT_FALSE(prefs_.SetString(kKey, "some value"));
+  EXPECT_FALSE(file_util::PathExists(prefs_dir_.Append(kKey)));
+}
+
+TEST_F(PrefsTest, SetStringCreateDir) {
+  const char kKey[] = "a-test-key";
+  const char kValue[] = "test value";
+  EXPECT_TRUE(prefs_.Init(FilePath(prefs_dir_.Append("subdir"))));
+  EXPECT_TRUE(prefs_.SetString(kKey, kValue));
+  string value;
+  EXPECT_TRUE(
+      file_util::ReadFileToString(prefs_dir_.Append("subdir").Append(kKey),
+                                  &value));
+  EXPECT_EQ(kValue, value);
+}
+
+TEST_F(PrefsTest, SetStringDirCreationFailure) {
+  EXPECT_TRUE(prefs_.Init(FilePath("/dev/null")));
+  const char kKey[] = "test-key";
+  EXPECT_FALSE(prefs_.SetString(kKey, "test value"));
+}
+
+TEST_F(PrefsTest, SetStringFileCreationFailure) {
+  const char kKey[] = "a-test-key";
+  file_util::CreateDirectory(prefs_dir_.Append(kKey));
+  EXPECT_FALSE(prefs_.SetString(kKey, "test value"));
+  EXPECT_TRUE(file_util::DirectoryExists(prefs_dir_.Append(kKey)));
+}
+
+TEST_F(PrefsTest, GetInt64) {
+  const char kKey[] = "test-key";
+  ASSERT_TRUE(SetValue(kKey, " \n 25 \t "));
+  int64_t value;
+  EXPECT_TRUE(prefs_.GetInt64(kKey, &value));
+  EXPECT_EQ(25, value);
+}
+
+TEST_F(PrefsTest, GetInt64BadValue) {
+  const char kKey[] = "test-key";
+  ASSERT_TRUE(SetValue(kKey, "30a"));
+  int64_t value;
+  EXPECT_FALSE(prefs_.GetInt64(kKey, &value));
+}
+
+TEST_F(PrefsTest, GetInt64Max) {
+  const char kKey[] = "test-key";
+  ASSERT_TRUE(SetValue(kKey, StringPrintf("%" PRIi64, kint64max)));
+  int64_t value;
+  EXPECT_TRUE(prefs_.GetInt64(kKey, &value));
+  EXPECT_EQ(kint64max, value);
+}
+
+TEST_F(PrefsTest, GetInt64Min) {
+  const char kKey[] = "test-key";
+  ASSERT_TRUE(SetValue(kKey, StringPrintf("%" PRIi64, kint64min)));
+  int64_t value;
+  EXPECT_TRUE(prefs_.GetInt64(kKey, &value));
+  EXPECT_EQ(kint64min, value);
+}
+
+TEST_F(PrefsTest, GetInt64Negative) {
+  const char kKey[] = "test-key";
+  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) {
+  const char kKey[] = "test_int";
+  EXPECT_TRUE(prefs_.SetInt64(kKey, -123));
+  string value;
+  EXPECT_TRUE(file_util::ReadFileToString(prefs_dir_.Append(kKey), &value));
+  EXPECT_EQ("-123", value);
+}
+
+TEST_F(PrefsTest, SetInt64BadKey) {
+  const char kKey[] = "s p a c e s";
+  EXPECT_FALSE(prefs_.SetInt64(kKey, 20));
+  EXPECT_FALSE(file_util::PathExists(prefs_dir_.Append(kKey)));
+}
+
+TEST_F(PrefsTest, SetInt64Max) {
+  const char kKey[] = "test-max-int";
+  EXPECT_TRUE(prefs_.SetInt64(kKey, kint64max));
+  string value;
+  EXPECT_TRUE(file_util::ReadFileToString(prefs_dir_.Append(kKey), &value));
+  EXPECT_EQ(StringPrintf("%" PRIi64, kint64max), value);
+}
+
+TEST_F(PrefsTest, SetInt64Min) {
+  const char kKey[] = "test-min-int";
+  EXPECT_TRUE(prefs_.SetInt64(kKey, kint64min));
+  string value;
+  EXPECT_TRUE(file_util::ReadFileToString(prefs_dir_.Append(kKey), &value));
+  EXPECT_EQ(StringPrintf("%" PRIi64, kint64min), value);
+}
+
+}  // namespace chromeos_update_engine