Base: Make RegistryOverrideManager support sharded/parallel tests.

base/test/test_reg_util_win_unittest.cc

+// Copyright 2013 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/compiler_specific.h"
+#include "base/guid.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/utf_string_conversions.h"
+#include "base/test/test_reg_util_win.h"
+#include "base/time/time.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace registry_util {
+
+namespace {
+const wchar_t kTestKeyPath[] = L"Software\\Chromium\\Foo\\Baz\\TestKey";
+const wchar_t kTestValueName[] = L"TestValue";
+}  // namespace
+
+class RegistryOverrideManagerTest : public testing::Test {
+ public:

[grt (UTC plus 2), 2013/11/07 02:39:33]

instead of public ctor and dtor, do this work in overrides of SetUp() and
TearDown(). also, make those overrides protected.

[tommycli, 2013/11/07 18:02:07]

Hmm... I was following 
https://code.google.com/p/googletest/wiki/FAQ#Should_I_use_the_constructor/de...

[grt (UTC plus 2), 2013/11/08 04:33:05]

Oh, cool. I hadn't seen that. Thanks for the pointer. In that case, I think the
ctor and dtor could be made protected. They're only to be called by subclasses
created by gtest, IIUC.

[tommycli, 2013/11/08 16:24:00]

Done.

+  RegistryOverrideManagerTest() {
+    // We assign a fake test key path to our test RegistryOverrideManager
+    // so we don't interfere with any actual RegistryOverrideManagers running
+    // on the system. This fake path will be auto-deleted by other
+    // RegistryOverrideManagers in case we crash.
+    key_to_delete_on_exit_ =
+        string16(RegistryOverrideManager::kTempTestKeyPath) +
+        L"\\" + base::Int64ToString16(base::Time::Now().ToInternalValue());
+    fake_test_key_root_ = key_to_delete_on_exit_ + L"\\" +
+        base::ASCIIToWide(base::GenerateGUID());
+
+    // Ensure a clean test environment.
+    base::win::RegKey key(HKEY_CURRENT_USER);
+    key.DeleteKey(fake_test_key_root_.c_str());
+    key.DeleteKey(kTestKeyPath);
+  }
+
+  virtual ~RegistryOverrideManagerTest() {
+    base::win::RegKey key(HKEY_CURRENT_USER);
+    key.DeleteKey(key_to_delete_on_exit_.c_str());
+  }
+
+ protected:
+  void AssertKeyExists(const string16& key_path) {
+    base::win::RegKey key;
+    ASSERT_EQ(ERROR_SUCCESS,

[grt (UTC plus 2), 2013/11/07 02:39:33]

as per http://www.chromium.org/developers/coding-style#Code_Formatting:
    ASSERT_EQ(ERROR_SUCCESS,
	      key.Open(HKEY_CURRENT_USER, key_path.c_str(), KEY_READ))
      << key_path << " does not exist.";
here and elsewhere

[tommycli, 2013/11/07 18:02:07]

Done.

+        key.Open(HKEY_CURRENT_USER, key_path.c_str(), KEY_READ)) <<
+            key_path << " does not exist.";
+  }
+
+  void AssertKeyAbsent(const string16& key_path) {
+    base::win::RegKey key;
+    ASSERT_NE(ERROR_SUCCESS,
+        key.Open(HKEY_CURRENT_USER, key_path.c_str(), KEY_READ)) <<
+            key_path << " exists but it should not.";
+  }
+
+  void CreateKey(const string16& key_path) {
+    base::win::RegKey key;
+    EXPECT_EQ(ERROR_SUCCESS,
+        key.Create(HKEY_CURRENT_USER, key_path.c_str(), KEY_ALL_ACCESS));
+  }
+
+  string16 FakeOverrideManagerPath(const base::Time& time) {
+    return fake_test_key_root_ + L"\\" +
+        base::Int64ToString16(time.ToInternalValue());
+  }
+
+  void CreateManager(const base::Time& timestamp) {
+    manager_.reset(new RegistryOverrideManager(timestamp, fake_test_key_root_));
+    manager_->OverrideRegistry(HKEY_CURRENT_USER, L"override_manager_unittest");
+  }
+
+  string16 key_to_delete_on_exit_;
+  string16 fake_test_key_root_;
+  scoped_ptr<RegistryOverrideManager> manager_;
+};
+
+TEST_F(RegistryOverrideManagerTest, Basic) {
+  CreateManager(base::Time::Now());
+
+  base::win::RegKey create_key;
+  EXPECT_EQ(ERROR_SUCCESS,
+      create_key.Create(HKEY_CURRENT_USER, kTestKeyPath, KEY_ALL_ACCESS));

[grt (UTC plus 2), 2013/11/07 02:39:33]

align with arg on previous line as per
http://google-styleguide.googlecode.com/svn/trunk/cppguide.xml#Function_Calls
here and elsewhere

[tommycli, 2013/11/07 18:02:07]

Done.

[grt (UTC plus 2), 2013/11/08 04:33:05]

really? i don't see a change here. for example:
  EXPECT_EQ(ERROR_SUCCESS,
            create_key.Create(...));

[tommycli, 2013/11/08 16:24:00]

Sorry I must have missed it. Patchsets 6 and 7 should address this.

+  EXPECT_TRUE(create_key.Valid());
+  EXPECT_EQ(ERROR_SUCCESS, create_key.WriteValue(kTestValueName, 42));
+  create_key.Close();
+
+  AssertKeyExists(kTestKeyPath);
+
+  DWORD value;
+  base::win::RegKey read_key;
+  EXPECT_EQ(ERROR_SUCCESS,
+      read_key.Open(HKEY_CURRENT_USER, kTestKeyPath, KEY_READ));
+  EXPECT_TRUE(read_key.Valid());
+  EXPECT_EQ(ERROR_SUCCESS, read_key.ReadValueDW(kTestValueName, &value));
+  EXPECT_EQ(42, value);
+  read_key.Close();
+
+  manager_.reset();
+
+  AssertKeyAbsent(kTestKeyPath);
+}
+
+TEST_F(RegistryOverrideManagerTest, DeleteStaleKeys) {
+  base::Time::Exploded kTestTimeExploded = {2013, 11, 1, 4, 0, 0, 0, 0};
+  base::Time kTestTime = base::Time::FromUTCExploded(kTestTimeExploded);
+
+  string16 path_garbage =
+      fake_test_key_root_ + L"\\Blah";
+  string16 path_very_stale =
+      FakeOverrideManagerPath(kTestTime - base::TimeDelta::FromDays(100));
+  string16 path_stale =
+      FakeOverrideManagerPath(kTestTime - base::TimeDelta::FromDays(5));
+  string16 path_current =
+      FakeOverrideManagerPath(kTestTime - base::TimeDelta::FromMinutes(1));
+  string16 path_future =
+      FakeOverrideManagerPath(kTestTime + base::TimeDelta::FromMinutes(1));
+
+  CreateKey(path_garbage);
+  CreateKey(path_very_stale);
+  CreateKey(path_stale);
+  CreateKey(path_current);
+  CreateKey(path_future);
+
+  CreateManager(kTestTime);
+  manager_.reset();
+
+  AssertKeyAbsent(path_garbage);
+  AssertKeyAbsent(path_very_stale);
+  AssertKeyAbsent(path_stale);
+  AssertKeyExists(path_current);
+  AssertKeyExists(path_future);
+}
+
+}  // namespace registry_util