components/sync_preferences/dual_layer_user_pref_store_unittest.cc

// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "components/sync_preferences/dual_layer_user_pref_store.h"

#include <map>
#include <set>
#include <string_view>

#include "base/memory/scoped_refptr.h"
#include "base/strings/string_util.h"
#include "base/test/mock_callback.h"
#include "base/test/scoped_feature_list.h"
#include "base/test/task_environment.h"
#include "base/values.h"
#include "components/prefs/testing_pref_store.h"
#include "components/sync/base/features.h"
#include "components/sync/test/test_sync_service.h"
#include "components/sync_preferences/pref_model_associator_client.h"
#include "components/sync_preferences/test_syncable_prefs_database.h"
#include "testing/gmock/include/gmock/gmock.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace sync_preferences {

namespace {

constexpr char kPref1[] = "regular.pref1";
constexpr char kPref2[] = "regular.pref2";
constexpr char kPref3[] = "regular.pref3";
constexpr char kPrefName[] = "regular.pref";
constexpr char kPriorityPrefName[] = "priority.pref";
constexpr char kNonExistentPrefName[] = "nonexistent-pref";
constexpr char kNonSyncablePrefName[] = "nonsyncable.pref";
constexpr char kHistorySensitivePrefName[] = "sensitive.pref";
constexpr char kMergeableListPref[] = "mergeable.list.pref";
constexpr char kMergeableDictPref1[] = "mergeable.dict.pref1";
constexpr char kMergeableDictPref2[] = "mergeable.dict.pref2";
constexpr char kCustomMergePref[] = "custom.merge.pref";
constexpr char kAlwaysSyncingPriorityPrefName[] =
    "always.syncing.priority.pref";
#if BUILDFLAG(IS_CHROMEOS)
constexpr char kOsPrefName[] = "os.pref";
constexpr char kOsPriorityPrefName[] = "os.priority.pref";
#endif  // BUILDFLAG(IS_CHROMEOS)

// Assigning an id of 0 to all the test prefs.
const TestSyncablePrefsDatabase::PrefsMap kSyncablePrefsDatabase = {
    {kPref1,
     {0, syncer::PREFERENCES, PrefSensitivity::kNone, MergeBehavior::kNone}},
    {kPref2,
     {0, syncer::PREFERENCES, PrefSensitivity::kNone, MergeBehavior::kNone}},
    {kPref3,
     {0, syncer::PREFERENCES, PrefSensitivity::kNone, MergeBehavior::kNone}},
    {kPrefName,
     {0, syncer::PREFERENCES, PrefSensitivity::kNone, MergeBehavior::kNone}},
    {kPriorityPrefName,
     {0, syncer::PRIORITY_PREFERENCES, PrefSensitivity::kNone,
      MergeBehavior::kNone}},
    {kHistorySensitivePrefName,
     {0, syncer::PREFERENCES, PrefSensitivity::kSensitiveRequiresHistory,
      MergeBehavior::kNone}},
    {kMergeableListPref,
     {0, syncer::PREFERENCES, PrefSensitivity::kNone,
      MergeBehavior::kMergeableListWithRewriteOnUpdate}},
    {kMergeableDictPref1,
     {0, syncer::PREFERENCES, PrefSensitivity::kNone,
      MergeBehavior::kMergeableDict}},
    {kMergeableDictPref2,
     {0, syncer::PREFERENCES, PrefSensitivity::kNone,
      MergeBehavior::kMergeableDict}},
    {kCustomMergePref,
     {0, syncer::PREFERENCES, PrefSensitivity::kNone, MergeBehavior::kCustom}},
    {kAlwaysSyncingPriorityPrefName,
     {0, syncer::PRIORITY_PREFERENCES,
      PrefSensitivity::kExemptFromUserControlWhileSignedIn,
      MergeBehavior::kNone}},
#if BUILDFLAG(IS_CHROMEOS)
    {kOsPrefName,
     {0, syncer::OS_PREFERENCES, PrefSensitivity::kNone, MergeBehavior::kNone}},
    {kOsPriorityPrefName,
     {0, syncer::OS_PRIORITY_PREFERENCES, PrefSensitivity::kNone,
      MergeBehavior::kNone}},
#endif  // BUILDFLAG(IS_CHROMEOS)
};

constexpr char kUserSelectedTypesPrefName[] =
    "dual_layer_user_pref_store.user_selected_sync_types";
#if BUILDFLAG(IS_CHROMEOS)
constexpr char kUserSelectedOsTypesPrefName[] =
    "dual_layer_user_pref_store.user_selected_os_sync_types";
#endif  // BUILDFLAG(IS_CHROMEOS)

base::Value MakeDict(
    const std::vector<std::pair<std::string, std::string>>& values) {
  base::Value::Dict dict;
  for (const auto& [key, value] : values) {
    dict.SetByDottedPath(key, value);
  }
  return base::Value(std::move(dict));
}

testing::AssertionResult ValueInStoreIs(const PrefStore& store,
                                        const std::string& pref,
                                        const base::Value& expected_value) {
  const base::Value* actual_value = nullptr;
  if (!store.GetValue(pref, &actual_value)) {
    return testing::AssertionFailure() << "Pref " << pref << " isn't present";
  }
  DCHECK(actual_value);
  if (expected_value != *actual_value) {
    return testing::AssertionFailure()
           << "Pref " << pref << " has value " << *actual_value
           << " but was expected to be " << expected_value;
  }
  return testing::AssertionSuccess();
}

testing::AssertionResult ValueInStoreIs(const PrefStore& store,
                                        const std::string& pref,
                                        const std::string& expected_value) {
  return ValueInStoreIs(store, pref, base::Value(expected_value));
}

testing::AssertionResult ValueInStoreIsAbsent(const PrefStore& store,
                                              const std::string& pref) {
  const base::Value* actual_value = nullptr;
  if (store.GetValue(pref, &actual_value)) {
    DCHECK(actual_value);
    return testing::AssertionFailure()
           << "Pref " << pref << " should be absent, but exists with value "
           << *actual_value;
  }
  return testing::AssertionSuccess();
}

testing::AssertionResult ValueInDictByDottedPathIs(
    const base::Value::Dict& dict,
    const std::string& key,
    const base::Value& expected_value) {
  if (const base::Value* actual_value = dict.FindByDottedPath(key);
      actual_value && *actual_value == expected_value) {
    return testing::AssertionSuccess();
  }
  return testing::AssertionFailure();
}

class MockPrefStoreObserver : public PrefStore::Observer {
 public:
  ~MockPrefStoreObserver() override = default;

  MOCK_METHOD(void, OnPrefValueChanged, (std::string_view), (override));
  MOCK_METHOD(void, OnInitializationCompleted, (bool succeeded), (override));
};

class MockReadErrorDelegate : public PersistentPrefStore::ReadErrorDelegate {
 public:
  MOCK_METHOD(void, OnError, (PersistentPrefStore::PrefReadError), (override));
};

class TestPrefModelAssociatorClient : public PrefModelAssociatorClient {
 public:
  TestPrefModelAssociatorClient()
      : syncable_prefs_database_(kSyncablePrefsDatabase) {}

  // PrefModelAssociatorClient implementation.
  base::Value MaybeMergePreferenceValues(
      std::string_view pref_name,
      const base::Value& local_value,
      const base::Value& server_value) const override {
    return base::Value();
  }

  const SyncablePrefsDatabase& GetSyncablePrefsDatabase() const override {
    return syncable_prefs_database_;
  }

 private:
  ~TestPrefModelAssociatorClient() override = default;
  TestSyncablePrefsDatabase syncable_prefs_database_;
};

class DualLayerUserPrefStoreTestBase : public testing::Test {
 public:
  explicit DualLayerUserPrefStoreTestBase(bool initialize) {
    local_store_ = base::MakeRefCounted<TestingPrefStore>();
    account_store_ = base::MakeRefCounted<TestingPrefStore>();
    pref_model_associator_client_ =
        base::MakeRefCounted<TestPrefModelAssociatorClient>();
    dual_layer_store_ = base::MakeRefCounted<DualLayerUserPrefStore>(
        local_store_, account_store_, pref_model_associator_client_);

    if (initialize) {
      local_store_->NotifyInitializationCompleted();
      account_store_->NotifyInitializationCompleted();
    }
    // Set preferences user selected type by default.
    dual_layer_store_->SetUserSelectedTypesForTest(
        {syncer::UserSelectableType::kPreferences});
  }

  TestingPrefStore* local_store() { return local_store_.get(); }
  TestingPrefStore* account_store() { return account_store_.get(); }
  DualLayerUserPrefStore* store() { return dual_layer_store_.get(); }

 protected:
  scoped_refptr<TestingPrefStore> local_store_;
  scoped_refptr<TestingPrefStore> account_store_;
  scoped_refptr<TestPrefModelAssociatorClient> pref_model_associator_client_;
  scoped_refptr<DualLayerUserPrefStore> dual_layer_store_;
};

class DualLayerUserPrefStoreTest : public DualLayerUserPrefStoreTestBase {
 public:
  DualLayerUserPrefStoreTest() : DualLayerUserPrefStoreTestBase(true) {
    // TODO(crbug.com/40256875): Add proper test setup to enable and disable
    // data types appropriately.
    dual_layer_store_->EnableType(syncer::PREFERENCES);
    dual_layer_store_->EnableType(syncer::PRIORITY_PREFERENCES);
#if BUILDFLAG(IS_CHROMEOS)
    dual_layer_store_->EnableType(syncer::OS_PREFERENCES);
    dual_layer_store_->EnableType(syncer::OS_PRIORITY_PREFERENCES);
#endif  // BUILDFLAG(IS_CHROMEOS)
  }
};

class DualLayerUserPrefStoreInitializationTest
    : public DualLayerUserPrefStoreTestBase {
 public:
  DualLayerUserPrefStoreInitializationTest()
      : DualLayerUserPrefStoreTestBase(false) {}
};

TEST_F(DualLayerUserPrefStoreInitializationTest,
       ForwardsInitializationSuccess) {
  // The local store and the account store are *not* initialized yet.
  ASSERT_FALSE(local_store()->IsInitializationComplete());
  ASSERT_FALSE(account_store()->IsInitializationComplete());

  // Accordingly, the dual-layer store is not initialized either.
  EXPECT_FALSE(store()->IsInitializationComplete());

  MockPrefStoreObserver observer;
  store()->AddObserver(&observer);

  local_store()->NotifyInitializationCompleted();
  // Only when both the stores are successfully initialized, does the dual-layer
  // store.
  EXPECT_CALL(observer, OnInitializationCompleted(true));
  account_store()->NotifyInitializationCompleted();

  EXPECT_TRUE(store()->IsInitializationComplete());
  EXPECT_EQ(store()->GetReadError(), PersistentPrefStore::PREF_READ_ERROR_NONE);

  store()->RemoveObserver(&observer);
}

TEST_F(DualLayerUserPrefStoreInitializationTest,
       ForwardsInitializationFailure) {
  // The local store and the account store are *not* initialized yet.
  ASSERT_FALSE(local_store()->IsInitializationComplete());
  ASSERT_FALSE(account_store()->IsInitializationComplete());

  // Accordingly, the dual-layer store is not initialized either.
  EXPECT_FALSE(store()->IsInitializationComplete());

  MockPrefStoreObserver observer;
  store()->AddObserver(&observer);

  // The local store encounters some read error.
  local_store()->set_read_error(
      PersistentPrefStore::PREF_READ_ERROR_JSON_PARSE);
  local_store()->set_read_success(false);

  // Since the local store reports the error, the dual-layer store should
  // forward it accordingly.
  EXPECT_CALL(observer, OnInitializationCompleted(false));
  local_store()->NotifyInitializationCompleted();
  account_store()->NotifyInitializationCompleted();

  EXPECT_TRUE(store()->IsInitializationComplete());
  EXPECT_EQ(store()->GetReadError(),
            PersistentPrefStore::PREF_READ_ERROR_JSON_PARSE);

  store()->RemoveObserver(&observer);
}

TEST_F(DualLayerUserPrefStoreInitializationTest,
       ShouldForwardLocalPrefStoreReadError) {
  local_store()->set_read_error(
      PersistentPrefStore::PREF_READ_ERROR_ACCESS_DENIED);
  // Read error is forwarded.
  EXPECT_EQ(PersistentPrefStore::PREF_READ_ERROR_ACCESS_DENIED,
            store()->ReadPrefs());
  EXPECT_EQ(PersistentPrefStore::PREF_READ_ERROR_ACCESS_DENIED,
            store()->GetReadError());
}

TEST_F(DualLayerUserPrefStoreInitializationTest,
       ShouldForwardAccountPrefStoreReadError) {
  account_store()->set_read_error(
      PersistentPrefStore::PREF_READ_ERROR_ACCESS_DENIED);
  // Read error is forwarded.
  EXPECT_EQ(PersistentPrefStore::PREF_READ_ERROR_ACCESS_DENIED,
            store()->ReadPrefs());
  EXPECT_EQ(PersistentPrefStore::PREF_READ_ERROR_ACCESS_DENIED,
            store()->GetReadError());
}

TEST_F(DualLayerUserPrefStoreInitializationTest,
       ShouldForwardLocalPrefStoreAsyncReadError) {
  local_store()->set_read_error(
      PersistentPrefStore::PREF_READ_ERROR_ACCESS_DENIED);

  // The callee is expected to take the ownership, hence the assignment to a raw
  // ptr.
  auto* read_error_delegate =
      new ::testing::StrictMock<MockReadErrorDelegate>();
  EXPECT_CALL(*read_error_delegate,
              OnError(PersistentPrefStore::PREF_READ_ERROR_ACCESS_DENIED));
  store()->ReadPrefsAsync(read_error_delegate);
  EXPECT_EQ(PersistentPrefStore::PREF_READ_ERROR_ACCESS_DENIED,
            store()->GetReadError());
}

TEST_F(DualLayerUserPrefStoreInitializationTest,
       ShouldForwardAccountPrefStoreAsyncReadError) {
  account_store()->set_read_error(
      PersistentPrefStore::PREF_READ_ERROR_ACCESS_DENIED);

  // The callee is expected to take the ownership, hence the assignment to a raw
  // ptr.
  auto* read_error_delegate =
      new ::testing::StrictMock<MockReadErrorDelegate>();
  EXPECT_CALL(*read_error_delegate,
              OnError(PersistentPrefStore::PREF_READ_ERROR_ACCESS_DENIED));
  store()->ReadPrefsAsync(read_error_delegate);
  EXPECT_EQ(PersistentPrefStore::PREF_READ_ERROR_ACCESS_DENIED,
            store()->GetReadError());
}

TEST_F(DualLayerUserPrefStoreInitializationTest,
       ShouldReportInitializationCompleteAfterRead) {
  EXPECT_FALSE(store()->IsInitializationComplete());
  store()->ReadPrefs();
  EXPECT_TRUE(store()->IsInitializationComplete());
}

TEST_F(DualLayerUserPrefStoreInitializationTest, HasReadErrorDelegate) {
  EXPECT_FALSE(store()->HasReadErrorDelegate());

  store()->ReadPrefsAsync(new MockReadErrorDelegate);
  EXPECT_TRUE(store()->HasReadErrorDelegate());
}

TEST_F(DualLayerUserPrefStoreInitializationTest,
       HasReadErrorDelegateWithNullDelegate) {
  EXPECT_FALSE(store()->HasReadErrorDelegate());

  store()->ReadPrefsAsync(nullptr);
  // Returns true even though no instance was passed.
  EXPECT_TRUE(store()->HasReadErrorDelegate());
}

TEST_F(DualLayerUserPrefStoreInitializationTest,
       ShouldReportInitializationCompleteAsyncReadAsync) {
  // Should report init completion after async read for underlying stores is
  // complete.
  local_store()->SetBlockAsyncRead(true);
  account_store()->SetBlockAsyncRead(true);
  EXPECT_FALSE(store()->IsInitializationComplete());
  store()->ReadPrefsAsync(nullptr);
  local_store()->SetBlockAsyncRead(false);
  EXPECT_FALSE(store()->IsInitializationComplete());
  account_store()->SetBlockAsyncRead(false);
  EXPECT_TRUE(store()->IsInitializationComplete());
}

TEST_F(DualLayerUserPrefStoreTest, ReadsFromLocalStore) {
  store()->GetLocalPrefStore()->SetValueSilently(kPrefName,
                                                 base::Value("local_value"), 0);

  // No value is set in the account store, so the one from the local store
  // should be returned.
  EXPECT_TRUE(ValueInStoreIs(*store(), kPrefName, "local_value"));

  // Reading the value should not have affected the account store.
  EXPECT_TRUE(ValueInStoreIsAbsent(*store()->GetAccountPrefStore(), kPrefName));
}

TEST_F(DualLayerUserPrefStoreTest, ReadsFromAccountStore) {
  store()->GetAccountPrefStore()->SetValueSilently(
      kPrefName, base::Value("account_value"), 0);

  // No value is set in the local store, so the one from the account store
  // should be returned.
  EXPECT_TRUE(ValueInStoreIs(*store(), kPrefName, "account_value"));

  // Reading the value should not have affected the local store.
  EXPECT_TRUE(ValueInStoreIsAbsent(*store()->GetLocalPrefStore(), kPrefName));
}

TEST_F(DualLayerUserPrefStoreTest, AccountTakesPrecedence) {
  store()->GetAccountPrefStore()->SetValueSilently(
      kPrefName, base::Value("account_value"), 0);
  store()->GetLocalPrefStore()->SetValueSilently(kPrefName,
                                                 base::Value("local_value"), 0);

  // Different values are set in both stores; the one from the account should
  // take precedence.
  EXPECT_TRUE(ValueInStoreIs(*store(), kPrefName, "account_value"));
}

TEST_F(DualLayerUserPrefStoreTest, ReadsFromBothStores) {
  // Three prefs: One is set in both stores, one only in the local store, and
  // one only in the account store.
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref1, base::Value("local_value1"), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref1, base::Value("account_value1"), 0);
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref2, base::Value("local_value2"), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref3, base::Value("account_value3"), 0);

  base::Value::Dict expected_values;
  // For the pref that exists in both stores, the account value should take
  // precedence.
  expected_values.SetByDottedPath(kPref1, "account_value1");
  // For the prefs that only exist in one store, their value should be returned.
  expected_values.SetByDottedPath(kPref2, "local_value2");
  expected_values.SetByDottedPath(kPref3, "account_value3");
  // TODO(crbug.com/40268520): Also set expectations for GetValue() since
  // GetValues() isn't used outside of tests and may not test the real codepath.
  EXPECT_THAT(store()->GetValues(), testing::IsSupersetOf(expected_values));
}

TEST_F(DualLayerUserPrefStoreTest, WritesToBothStores) {
  // Three prefs: One is set in both stores, one only in the local store, and
  // one only in the account store.
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref1, base::Value("local_value1"), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref1, base::Value("account_value1"), 0);
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref2, base::Value("local_value2"), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref3, base::Value("account_value3"), 0);

  // Update all three prefs.
  store()->SetValue(kPref1, base::Value("new_value1"), 0);
  store()->SetValue(kPref2, base::Value("new_value2"), 0);
  store()->SetValue(kPref3, base::Value("new_value3"), 0);

  // The new values should be returned from the dual-layer store...
  ASSERT_TRUE(ValueInStoreIs(*store(), kPref1, "new_value1"));
  ASSERT_TRUE(ValueInStoreIs(*store(), kPref2, "new_value2"));
  ASSERT_TRUE(ValueInStoreIs(*store(), kPref3, "new_value3"));
  // ...but should also be stored in both the local and the account store.
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetLocalPrefStore(), kPref1, "new_value1"));
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetLocalPrefStore(), kPref2, "new_value2"));
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetLocalPrefStore(), kPref3, "new_value3"));
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetAccountPrefStore(), kPref1, "new_value1"));
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetAccountPrefStore(), kPref2, "new_value2"));
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetAccountPrefStore(), kPref3, "new_value3"));
}

TEST_F(DualLayerUserPrefStoreTest, RemovesFromBothStores) {
  // Three prefs: One is set in both stores, one only in the local store, and
  // one only in the account store.
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref1, base::Value("local_value1"), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref1, base::Value("account_value1"), 0);
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref2, base::Value("local_value2"), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref3, base::Value("account_value3"), 0);

  // Remove all three prefs.
  store()->RemoveValue(kPref1, 0);
  store()->RemoveValue(kPref2, 0);
  store()->RemoveValue(kPref3, 0);

  // The values should now be absent from the dual-layer store...
  ASSERT_TRUE(ValueInStoreIsAbsent(*store(), kPref1));
  ASSERT_TRUE(ValueInStoreIsAbsent(*store(), kPref2));
  ASSERT_TRUE(ValueInStoreIsAbsent(*store(), kPref3));
  // ...as well as from both the local and the account store.
  EXPECT_TRUE(ValueInStoreIsAbsent(*store()->GetLocalPrefStore(), kPref1));
  EXPECT_TRUE(ValueInStoreIsAbsent(*store()->GetLocalPrefStore(), kPref2));
  EXPECT_TRUE(ValueInStoreIsAbsent(*store()->GetLocalPrefStore(), kPref3));
  EXPECT_TRUE(ValueInStoreIsAbsent(*store()->GetAccountPrefStore(), kPref1));
  EXPECT_TRUE(ValueInStoreIsAbsent(*store()->GetAccountPrefStore(), kPref2));
  EXPECT_TRUE(ValueInStoreIsAbsent(*store()->GetAccountPrefStore(), kPref3));
}

TEST_F(DualLayerUserPrefStoreTest,
       RemovesValuesByPrefixSilentlyFromBothStores) {
  // Three prefs: One is set only in the local store, one only in the account
  // store, and one is set in both stores.
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref1, base::Value("local_value1"), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref2, base::Value("account_value2"), 0);
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref3, base::Value("local_value3"), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref3, base::Value("account_value3"), 0);

  // Remove `kPref1` from the local store.
  store()->RemoveValuesByPrefixSilently(kPref1);
  EXPECT_TRUE(ValueInStoreIsAbsent(*store(), kPref1));
  // `kPref2` and `kPref3` are still there.
  EXPECT_TRUE(ValueInStoreIs(*store(), kPref2, "account_value2"));
  EXPECT_TRUE(ValueInStoreIs(*store(), kPref3, "account_value3"));

  // Remove `kPref2` from the account store.
  store()->RemoveValuesByPrefixSilently(kPref2);
  EXPECT_TRUE(ValueInStoreIsAbsent(*store(), kPref2));
  // `kPref3` is still there.
  EXPECT_TRUE(ValueInStoreIs(*store(), kPref3, "account_value3"));

  // Remove `kPref3` using a prefix `kPrefName`.
  ASSERT_TRUE(base::StartsWith(kPref3, kPrefName));
  store()->RemoveValuesByPrefixSilently(kPrefName);
  EXPECT_TRUE(ValueInStoreIsAbsent(*store(), kPref3));
}

TEST_F(DualLayerUserPrefStoreTest,
       RemoveValuesByPrefixSilentlyRemovesMultiplePrefs) {
  // Three prefs: Each set in both the stores.
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref1, base::Value("local_value1"), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref1, base::Value("account_value1"), 0);
  // `kPrefName` is a prefix of `kPref1` and is used to remove `kPref1`.
  store()->GetLocalPrefStore()->SetValueSilently(
      kPrefName, base::Value("local_value2"), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPrefName, base::Value("account_value2"), 0);
  // `kPriorityPrefName` does not have `kPref1` as prefix.
  store()->GetLocalPrefStore()->SetValueSilently(
      kPriorityPrefName, base::Value("local_value3"), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPriorityPrefName, base::Value("account_value3"), 0);

  // Remove `kPref1` using prefix `kPrefName`.
  ASSERT_TRUE(base::StartsWith(kPref1, kPrefName));
  ASSERT_FALSE(base::StartsWith(kPriorityPrefName, kPrefName));

  store()->RemoveValuesByPrefixSilently(kPrefName);
  EXPECT_TRUE(ValueInStoreIsAbsent(*store(), kPref1));
  EXPECT_TRUE(ValueInStoreIsAbsent(*store(), kPrefName));
  // `kPriorityPrefName` is still there.
  EXPECT_TRUE(ValueInStoreIs(*store(), kPriorityPrefName, "account_value3"));
}

TEST_F(DualLayerUserPrefStoreTest, DoesNotReturnNonexistentPref) {
  store()->SetValueSilently(kPrefName, MakeDict({{"key", "value"}}), 0);

  // The existing pref can be queried.
  ASSERT_TRUE(store()->GetValue(kPrefName, nullptr));
  ASSERT_TRUE(store()->GetMutableValue(kPrefName, nullptr));

  // But a non-existing pref can't.
  EXPECT_FALSE(store()->GetValue(kNonExistentPrefName, nullptr));
  EXPECT_FALSE(store()->GetMutableValue(kNonExistentPrefName, nullptr));
}

TEST_F(DualLayerUserPrefStoreTest, WritesMutableValueFromLocalToBothStores) {
  const base::Value original_value = MakeDict({{"key", "value"}});

  // A dictionary-type value is present in the local store.
  store()->GetLocalPrefStore()->SetValueSilently(kPrefName,
                                                 original_value.Clone(), 0);

  // GetMutableValue() should return that value. In practice, this API is used
  // by ScopedDictPrefUpdate and ScopedListPrefUpdate.
  base::Value* mutable_value = nullptr;
  ASSERT_TRUE(store()->GetMutableValue(kPrefName, &mutable_value));
  ASSERT_TRUE(mutable_value);
  ASSERT_EQ(*mutable_value, original_value);

  // Update it!
  mutable_value->GetDict().Set("key", "new_value");

  const base::Value expected_value = mutable_value->Clone();

  // After updating the value, clients have to call ReportValueChanged() to let
  // the store know it has changed. The dual-layer store uses this to reconcile
  // between the two underlying stores.
  store()->ReportValueChanged(kPrefName, 0);

  // The new value should of course be returned from the dual-layer store now,
  // but it should also have been written to both of the underlying stores.
  ASSERT_TRUE(ValueInStoreIs(*store(), kPrefName, expected_value));
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetLocalPrefStore(), kPrefName, expected_value));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(), kPrefName,
                             expected_value));
}

TEST_F(DualLayerUserPrefStoreTest, WritesMutableValueFromAccountToBothStores) {
  const base::Value original_value = MakeDict({{"key", "value"}});

  // A dictionary-type value is present in the account store.
  store()->GetAccountPrefStore()->SetValueSilently(kPrefName,
                                                   original_value.Clone(), 0);

  // GetMutableValue() should return that value. In practice, this API is used
  // by ScopedDictPrefUpdate and ScopedListPrefUpdate.
  base::Value* mutable_value = nullptr;
  ASSERT_TRUE(store()->GetMutableValue(kPrefName, &mutable_value));
  ASSERT_TRUE(mutable_value);
  ASSERT_EQ(*mutable_value, original_value);

  // Update it!
  mutable_value->GetDict().Set("key", "new_value");

  const base::Value expected_value = mutable_value->Clone();

  // After updating the value, clients have to call ReportValueChanged() to let
  // the store know it has changed. The dual-layer store uses this to reconcile
  // between the two underlying stores.
  store()->ReportValueChanged(kPrefName, 0);

  // The new value should of course be returned from the dual-layer store now,
  // but it should also have been written to both of the underlying stores.
  ASSERT_TRUE(ValueInStoreIs(*store(), kPrefName, expected_value));
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetLocalPrefStore(), kPrefName, expected_value));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(), kPrefName,
                             expected_value));
}

TEST_F(DualLayerUserPrefStoreTest, WritesMutableValueFromBothToBothStores) {
  const base::Value original_local_value = MakeDict({{"key", "local_value"}});
  const base::Value original_account_value =
      MakeDict({{"key", "account_value"}});

  // A dictionary-type value is present in both of the underlying stores.
  store()->GetLocalPrefStore()->SetValueSilently(
      kPrefName, original_local_value.Clone(), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPrefName, original_account_value.Clone(), 0);

  // GetMutableValue() should return that value. In practice, this API is used
  // by ScopedDictPrefUpdate and ScopedListPrefUpdate.
  base::Value* mutable_value = nullptr;
  ASSERT_TRUE(store()->GetMutableValue(kPrefName, &mutable_value));
  ASSERT_TRUE(mutable_value);
  ASSERT_EQ(*mutable_value, original_account_value);

  // Update it!
  mutable_value->GetDict().Set("key", "new_value");

  const base::Value expected_value = mutable_value->Clone();

  // After updating the value, clients have to call ReportValueChanged() to let
  // the store know it has changed. The dual-layer store uses this to reconcile
  // between the two underlying stores.
  store()->ReportValueChanged(kPrefName, 0);

  // The new value should of course be returned from the dual-layer store now,
  // but it should also have been written to both of the underlying stores.
  ASSERT_TRUE(ValueInStoreIs(*store(), kPrefName, expected_value));
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetLocalPrefStore(), kPrefName, expected_value));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(), kPrefName,
                             expected_value));
}

TEST_F(DualLayerUserPrefStoreTest, ClearsMutableValueFromBothStores) {
  // A dictionary-type value is present in both of the underlying stores.
  const base::Value original_value = MakeDict({{"key", "value"}});
  store()->SetValueSilently(kPrefName, original_value.Clone(), 0);
  ASSERT_TRUE(
      ValueInStoreIs(*store()->GetLocalPrefStore(), kPrefName, original_value));
  ASSERT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(), kPrefName,
                             original_value));

  // GetMutableValue() should return that value. In practice, this API is used
  // by ScopedDictPrefUpdate and ScopedListPrefUpdate.
  base::Value* mutable_value = nullptr;
  ASSERT_TRUE(store()->GetMutableValue(kPrefName, &mutable_value));
  ASSERT_TRUE(mutable_value);
  ASSERT_EQ(*mutable_value, original_value);

  mutable_value->GetDict().Set("key", "new_value");

  // While the mutable value is "pending" (hasn't been "released" via
  // ReportValueChanged()), the pref gets cleared.
  // This shouldn't usually happen in practice, but in theory it could.
  store()->RemoveValue(kPrefName, 0);

  // Now the client that called GetMutableValue() previously reports that it is
  // done changing the value.
  store()->ReportValueChanged(kPrefName, 0);

  // The value should have been removed from both of the stores.
  EXPECT_TRUE(ValueInStoreIsAbsent(*store(), kPrefName));
  EXPECT_TRUE(ValueInStoreIsAbsent(*store()->GetLocalPrefStore(), kPrefName));
  EXPECT_TRUE(ValueInStoreIsAbsent(*store()->GetAccountPrefStore(), kPrefName));
}

TEST_F(DualLayerUserPrefStoreTest, NotifiesOfPrefChanges) {
  // Three prefs: One is set in both stores, one only in the local store, and
  // one only in the account store.
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref1, base::Value("local_value1"), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref1, base::Value("account_value1"), 0);
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref2, base::Value("local_value2"), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref3, base::Value("account_value3"), 0);

  testing::StrictMock<MockPrefStoreObserver> observer;
  store()->AddObserver(&observer);

  // Update the prefs. In each case, there should be exactly one pref-change
  // notification.
  EXPECT_CALL(observer, OnPrefValueChanged(kPref1));
  EXPECT_CALL(observer, OnPrefValueChanged(kPref2));
  EXPECT_CALL(observer, OnPrefValueChanged(kPref3));
  store()->SetValue(kPref1, base::Value("new_value1"), 0);
  store()->SetValue(kPref2, base::Value("new_value2"), 0);
  store()->SetValue(kPref3, base::Value("new_value3"), 0);

  // Remove the prefs. Again, there should be one notification each.
  EXPECT_CALL(observer, OnPrefValueChanged(kPref1));
  EXPECT_CALL(observer, OnPrefValueChanged(kPref2));
  EXPECT_CALL(observer, OnPrefValueChanged(kPref3));
  store()->RemoveValue(kPref1, 0);
  store()->RemoveValue(kPref2, 0);
  store()->RemoveValue(kPref3, 0);

  store()->RemoveObserver(&observer);
}

TEST_F(DualLayerUserPrefStoreTest,
       NotifiesOfPrefChangesOnlyIfEffectiveValueChanges) {
  testing::StrictMock<MockPrefStoreObserver> observer;
  store()->AddObserver(&observer);

  // Add a pref to both stores but with different values.
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref1, base::Value("local_value1"), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref1, base::Value("account_value1"), 0);

  // Should not lead to a notification since the effective value hasn't changed.
  store()->SetValue(kPref1, base::Value("account_value1"), 0);
  // But should still update the local pref store.
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetLocalPrefStore(), kPref1, "account_value1"));

  // Add a pref to the local store only.
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref2, base::Value("local_value2"), 0);

  // Should not lead to a notification since the effective value hasn't changed.
  store()->SetValue(kPref2, base::Value("local_value2"), 0);
  // But should still update the account pref store.
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetAccountPrefStore(), kPref2, "local_value2"));

  // Add a pref to the account store only.
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref3, base::Value("account_value3"), 0);

  // Should not lead to a notification since the effective value hasn't changed.
  store()->SetValue(kPref3, base::Value("account_value3"), 0);
  // But should still update the local pref store.
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetLocalPrefStore(), kPref3, "account_value3"));

  // Add the same pref to both stores.
  store()->SetValueSilently(kPrefName, base::Value("value"), 0);

  EXPECT_CALL(observer, OnPrefValueChanged(kPrefName));
  // Effective value changes, so expect a notification.
  store()->SetValue(kPrefName, base::Value("new_value"), 0);

  store()->RemoveObserver(&observer);
}

TEST_F(DualLayerUserPrefStoreTest, NotifiesOfPrefChangesInUnderlyingStores) {
  // Three prefs: One is set in both stores, one only in the local store, and
  // one only in the account store.
  store()->GetLocalPrefStore()->SetValueSilently(kPref1,
                                                 base::Value("local_value"), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref2, base::Value("account_value"), 0);

  testing::StrictMock<MockPrefStoreObserver> observer;
  store()->AddObserver(&observer);

  // Update the prefs by writing directly to the underlying stores. (For the
  // account store, that happens when a pref is updated from Sync. For the local
  // store, it shouldn't happen in practice.)
  // The dual-layer store should notify about these changes.
  EXPECT_CALL(observer, OnPrefValueChanged(kPref1));
  EXPECT_CALL(observer, OnPrefValueChanged(kPref2));
  store()->GetLocalPrefStore()->SetValue(kPref1, base::Value("new_value1"), 0);
  store()->GetAccountPrefStore()->SetValue(kPref2, base::Value("new_value2"),
                                           0);

  // Same with removals directly in the underlying stores.
  EXPECT_CALL(observer, OnPrefValueChanged(kPref1));
  EXPECT_CALL(observer, OnPrefValueChanged(kPref2));
  store()->GetLocalPrefStore()->RemoveValue(kPref1, 0);
  store()->GetAccountPrefStore()->RemoveValue(kPref2, 0);

  store()->RemoveObserver(&observer);
}

TEST_F(DualLayerUserPrefStoreTest,
       NotifiesOfPrefChangesInUnderlyingStoresOnlyIfEffectiveValueChanges) {
  // Two prefs: One is set only in the local store, the other set in both
  // stores.
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref1, base::Value("local_value1"), 0);
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref2, base::Value("local_value2"), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref2, base::Value("account_value2"), 0);

  testing::StrictMock<MockPrefStoreObserver> observer;
  store()->AddObserver(&observer);

  // Update the prefs by writing directly to the underlying stores.
  // The dual-layer store should notify about these changes only when the
  // the *effective* value changes, i.e. not when a pref is changed in the
  // local store that also has a value in the account store.
  EXPECT_CALL(observer, OnPrefValueChanged(kPref1));
  store()->GetLocalPrefStore()->SetValue(kPref1, base::Value("new_value1"), 0);
  // Should not lead to a notification since the effective value has not
  // changed.
  store()->GetLocalPrefStore()->SetValue(kPref2, base::Value("new_value2"), 0);

  // Same with removals directly in the underlying stores.
  EXPECT_CALL(observer, OnPrefValueChanged(kPref1));
  store()->GetLocalPrefStore()->RemoveValue(kPref1, 0);
  store()->GetLocalPrefStore()->RemoveValue(kPref2, 0);

  store()->RemoveObserver(&observer);
}

TEST_F(DualLayerUserPrefStoreTest, NotifiesOfRemoveOnlyIfPrefExists) {
  // Add a single pref.
  store()->SetValueSilently(kPref1, base::Value("value"), 0);

  testing::StrictMock<MockPrefStoreObserver> observer;
  store()->AddObserver(&observer);

  // Only the added pref should raise a notification.
  EXPECT_CALL(observer, OnPrefValueChanged(kPref1));
  store()->RemoveValue(kPref1, 0);
  // `kPref2` was not added and should not raise any notification.
  store()->RemoveValue(kPref2, 0);

  store()->RemoveObserver(&observer);
}

TEST_F(DualLayerUserPrefStoreTest, NotifiesOfMutableValuePrefChanges) {
  // Three dictionary-valued prefs: One is set in both stores, one only in the
  // local store, and one only in the account store.
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref1, MakeDict({{"key1", "local_value1"}}), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref1, MakeDict({{"key1", "account_value1"}}), 0);
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref2, MakeDict({{"key2", "local_value2"}}), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref3, MakeDict({{"key3", "account_value3"}}), 0);

  testing::StrictMock<MockPrefStoreObserver> observer;
  store()->AddObserver(&observer);

  // Update the prefs via GetMutableValue() + ReportValueChanged(). In each
  // case, there should be exactly one pref-change notification.
  EXPECT_CALL(observer, OnPrefValueChanged(kPref1));
  EXPECT_CALL(observer, OnPrefValueChanged(kPref2));
  EXPECT_CALL(observer, OnPrefValueChanged(kPref3));

  base::Value* value1 = nullptr;
  ASSERT_TRUE(store()->GetMutableValue(kPref1, &value1));
  value1->GetDict().Set("key1", "new_value1");
  store()->ReportValueChanged(kPref1, 0);

  base::Value* value2 = nullptr;
  ASSERT_TRUE(store()->GetMutableValue(kPref2, &value2));
  value2->GetDict().Set("key2", "new_value2");
  store()->ReportValueChanged(kPref2, 0);

  base::Value* value3 = nullptr;
  ASSERT_TRUE(store()->GetMutableValue(kPref3, &value3));
  value3->GetDict().Set("key3", "new_value3");
  store()->ReportValueChanged(kPref3, 0);

  store()->RemoveObserver(&observer);
}

TEST_F(DualLayerUserPrefStoreTest, ShouldAddOnlySyncablePrefsToAccountStore) {
  constexpr char kNewValue[] = "new_value";

  store()->SetValue(kPrefName, base::Value(kNewValue), 0);

  // Value should be set in both the stores.
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetLocalPrefStore(), kPrefName, kNewValue));
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetAccountPrefStore(), kPrefName, kNewValue));

  store()->SetValue(kNonSyncablePrefName, base::Value(kNewValue), 0);

  // No value should be set in the account store.
  EXPECT_TRUE(ValueInStoreIsAbsent(*store()->GetAccountPrefStore(),
                                   kNonSyncablePrefName));
  // Value is only set in the local store.
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(),
                             kNonSyncablePrefName, kNewValue));
}

TEST_F(DualLayerUserPrefStoreTest, ShouldCommitPendingWritesForBothStores) {
  base::test::SingleThreadTaskEnvironment task_env;

  ::testing::StrictMock<base::MockOnceClosure> reply_callback;
  ::testing::StrictMock<base::MockOnceClosure> done_callback;

  EXPECT_CALL(reply_callback, Run);
  EXPECT_CALL(done_callback, Run);
  store()->CommitPendingWrite(reply_callback.Get(), done_callback.Get());
  task_env.RunUntilIdle();
  EXPECT_TRUE(local_store()->committed());
  EXPECT_TRUE(account_store()->committed());
}

// Tests that notifications are not sent out if the same value already exists in
// the local store, i.e. the effective value is unchanged.
TEST_F(
    DualLayerUserPrefStoreTest,
    ShouldNotNotifyIfEffectiveValueIsUnchangedUponSetValueInAccountStoreOnly) {
  store()->GetLocalPrefStore()->SetValueSilently(kPrefName,
                                                 base::Value("value"), 0);

  testing::StrictMock<MockPrefStoreObserver> observer;
  store()->AddObserver(&observer);

  testing::StrictMock<MockPrefStoreObserver> account_store_observer;
  store()->GetAccountPrefStore()->AddObserver(&account_store_observer);

  // Effective value in the dual pref store is unchanged, so there shouldn't be
  // any calls to the observer.
  EXPECT_CALL(observer, OnPrefValueChanged).Times(0);
  // Since a new pref is added to the account store, its observers are still
  // notified.
  EXPECT_CALL(account_store_observer, OnPrefValueChanged);

  store()->SetValueInAccountStoreOnly(kPrefName, base::Value("value"), 0);

  store()->GetAccountPrefStore()->RemoveObserver(&account_store_observer);
  store()->RemoveObserver(&observer);
}

TEST_F(DualLayerUserPrefStoreTest,
       ShouldNotifyIfEffectiveValueChangesUponSetValueInAccountStoreOnly) {
  store()->GetLocalPrefStore()->SetValueSilently(kPrefName,
                                                 base::Value("value"), 0);

  testing::StrictMock<MockPrefStoreObserver> observer;
  store()->AddObserver(&observer);

  testing::StrictMock<MockPrefStoreObserver> account_store_observer;
  store()->GetAccountPrefStore()->AddObserver(&account_store_observer);

  // Effective value is changing, so observers should be notified.
  EXPECT_CALL(observer, OnPrefValueChanged);
  EXPECT_CALL(account_store_observer, OnPrefValueChanged);

  store()->SetValueInAccountStoreOnly(kPrefName, base::Value("new value"), 0);

  store()->GetAccountPrefStore()->RemoveObserver(&account_store_observer);
  store()->RemoveObserver(&observer);
}

class DualLayerUserPrefStoreTestForTypes
    : public DualLayerUserPrefStoreTestBase {
 public:
  DualLayerUserPrefStoreTestForTypes() : DualLayerUserPrefStoreTestBase(true) {}
};

TEST_F(DualLayerUserPrefStoreTestForTypes,
       ShouldClearAllSyncablePrefsOfTypeFromAccountStoreOnDisable) {
  store()->EnableType(syncer::PREFERENCES);
  store()->EnableType(syncer::PRIORITY_PREFERENCES);

  store()->SetValue(kPrefName, base::Value("pref-value"), 0);
  store()->SetValue(kPriorityPrefName, base::Value("priority-value"), 0);

  ASSERT_TRUE(
      ValueInStoreIs(*store()->GetAccountPrefStore(), kPrefName, "pref-value"));
  ASSERT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(), kPriorityPrefName,
                             "priority-value"));

  store()->DisableTypeAndClearAccountStore(syncer::PRIORITY_PREFERENCES);
  // The regular pref remains untouched.
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetAccountPrefStore(), kPrefName, "pref-value"));
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetLocalPrefStore(), kPrefName, "pref-value"));

  // Priority prefs are cleared from the account store.
  EXPECT_TRUE(
      ValueInStoreIsAbsent(*store()->GetAccountPrefStore(), kPriorityPrefName));
  // Local pref store is not affected.
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kPriorityPrefName,
                             "priority-value"));

  // The value should no longer be there in the account store even if the type
  // is enabled again.
  store()->EnableType(syncer::PRIORITY_PREFERENCES);
  EXPECT_TRUE(
      ValueInStoreIsAbsent(*store()->GetAccountPrefStore(), kPriorityPrefName));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kPriorityPrefName,
                             "priority-value"));
}

TEST_F(DualLayerUserPrefStoreTestForTypes,
       ShouldNotifyObserversOnDisableIfEffectiveValueChanges) {
  store()->EnableType(syncer::PREFERENCES);

  testing::StrictMock<MockPrefStoreObserver> observer;
  store()->AddObserver(&observer);

  account_store()->SetValueSilently(kPrefName, base::Value("account_value"), 0);
  local_store()->SetValueSilently(kPrefName, base::Value("local_value"), 0);

  EXPECT_CALL(observer, OnPrefValueChanged(kPrefName));

  ASSERT_TRUE(ValueInStoreIs(*store(), kPrefName, "account_value"));
  store()->DisableTypeAndClearAccountStore(syncer::PREFERENCES);
  ASSERT_TRUE(ValueInStoreIs(*store(), kPrefName, "local_value"));

  store()->RemoveObserver(&observer);
}

TEST_F(DualLayerUserPrefStoreTestForTypes,
       ShouldNotifyObserversOnDisableIfLocalValueDoesNotExist) {
  store()->EnableType(syncer::PREFERENCES);

  testing::StrictMock<MockPrefStoreObserver> observer;
  store()->AddObserver(&observer);

  account_store()->SetValueSilently(kPrefName, base::Value("account_value"), 0);

  EXPECT_CALL(observer, OnPrefValueChanged(kPrefName));

  ASSERT_TRUE(ValueInStoreIs(*store(), kPrefName, "account_value"));
  store()->DisableTypeAndClearAccountStore(syncer::PREFERENCES);
  ASSERT_TRUE(ValueInStoreIsAbsent(*store(), kPrefName));

  store()->RemoveObserver(&observer);
}

TEST_F(DualLayerUserPrefStoreTestForTypes,
       ShouldNotNotifyObserversOnDisableIfEffectiveValueDoesNotChange) {
  store()->EnableType(syncer::PREFERENCES);

  testing::StrictMock<MockPrefStoreObserver> observer;
  store()->AddObserver(&observer);

  account_store()->SetValueSilently(kPrefName, base::Value("pref-value"), 0);
  local_store()->SetValueSilently(kPrefName, base::Value("pref-value"), 0);

  ASSERT_TRUE(ValueInStoreIs(*store(), kPrefName, "pref-value"));
  store()->DisableTypeAndClearAccountStore(syncer::PREFERENCES);
  ASSERT_TRUE(ValueInStoreIs(*store(), kPrefName, "pref-value"));

  // `observer` was not notified of any pref change.
  store()->RemoveObserver(&observer);
}

TEST_F(DualLayerUserPrefStoreTestForTypes,
       ShouldReturnAccountValueForNotActiveTypes) {
  account_store()->SetValueSilently(kPrefName, base::Value("pref-value"), 0);
  ASSERT_TRUE(ValueInStoreIs(*account_store(), kPrefName, "pref-value"));

  // PREFERENCES type is not active.
  ASSERT_EQ(0u, store()->GetActiveTypesForTest().count(syncer::PREFERENCES));

  // `kPrefName` is read from the account store even if PREFERENCES type is not
  // active.
  {
    const base::Value* value = nullptr;
    ASSERT_TRUE(store()->GetValue(kPrefName, &value));
    EXPECT_EQ(*value, base::Value("pref-value"));
  }
  {
    base::Value* value = nullptr;
    ASSERT_TRUE(store()->GetMutableValue(kPrefName, &value));
    EXPECT_EQ(*value, base::Value("pref-value"));
  }
}

TEST_F(DualLayerUserPrefStoreTestForTypes,
       ShouldClearAllPrefsFromAccountStoreOnDisableAllTypes) {
  store()->EnableType(syncer::PREFERENCES);

  account_store()->SetValue(kPrefName, base::Value("pref-value"), 0);
  // Garbage value in account store.
  account_store()->SetValue(kNonSyncablePrefName,
                            base::Value("non-syncable-pref-value"), 0);

  ASSERT_TRUE(ValueInStoreIs(*store(), kPrefName, "pref-value"));
  // Non-syncable prefs are not returned by the getters.
  ASSERT_TRUE(ValueInStoreIsAbsent(*store(), kNonSyncablePrefName));
  ASSERT_TRUE(ValueInStoreIs(*account_store(), kNonSyncablePrefName,
                             "non-syncable-pref-value"));

  testing::StrictMock<MockPrefStoreObserver> observer;
  store()->AddObserver(&observer);

  // Notification for syncable prefs.
  EXPECT_CALL(observer, OnPrefValueChanged(kPrefName));
  // No notification for garbage values.
  EXPECT_CALL(observer, OnPrefValueChanged(kNonSyncablePrefName)).Times(0);

  store()->DisableTypeAndClearAccountStore(syncer::PREFERENCES);

  // All values get removed from the account store when all types are disabled.
  EXPECT_TRUE(ValueInStoreIsAbsent(*account_store(), kPrefName));
  EXPECT_TRUE(ValueInStoreIsAbsent(*account_store(), kNonSyncablePrefName));

  store()->RemoveObserver(&observer);
}

TEST_F(DualLayerUserPrefStoreTestForTypes,
       ShouldSetAccountValueForNotActiveTypesIfAlreadyExists) {
  account_store()->SetValueSilently(kPrefName, base::Value("account_value"), 0);
  ASSERT_TRUE(ValueInStoreIs(*account_store(), kPrefName, "account_value"));

  // PREFERENCES type is not active.
  ASSERT_EQ(0u, store()->GetActiveTypesForTest().count(syncer::PREFERENCES));

  // `kPrefName` is set to the account store even if PREFERENCES type is not
  // active since it already exists in the account store.
  {
    store()->SetValue(kPrefName, base::Value("new_value1"), 0);
    EXPECT_TRUE(ValueInStoreIs(*account_store(), kPrefName, "new_value1"));
  }
  {
    store()->SetValueSilently(kPrefName, base::Value("new_value2"), 0);
    EXPECT_TRUE(ValueInStoreIs(*account_store(), kPrefName, "new_value2"));
  }
  {
    base::Value* value = nullptr;
    ASSERT_TRUE(store()->GetMutableValue(kPrefName, &value));
    *value = base::Value("new_value3");
    store()->ReportValueChanged(kPrefName, 0);
    EXPECT_TRUE(ValueInStoreIs(*account_store(), kPrefName, "new_value3"));
  }
}

class DualLayerUserPrefStoreTestWithoutUseSelectedTypes
    : public DualLayerUserPrefStoreTestForTypes {
 public:
  DualLayerUserPrefStoreTestWithoutUseSelectedTypes() {
    feature_list_.InitAndDisableFeature(
        syncer::kSyncPreferencesUseSelectedTypes);
  }

 private:
  base::test::ScopedFeatureList feature_list_;
};

TEST_F(DualLayerUserPrefStoreTestWithoutUseSelectedTypes,
       ShouldAddOnlyEnabledTypePrefsToAccountStore) {
  // Enable only PRIORITY_PREFERENCES
  store()->EnableType(syncer::PRIORITY_PREFERENCES);

  store()->SetValue(kPriorityPrefName, base::Value("priority-value"), 0);
  store()->SetValue(kPrefName, base::Value("pref-value"), 0);

  ASSERT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(), kPriorityPrefName,
                             "priority-value"));
  // Regular pref is only added to the local pref store.
  EXPECT_TRUE(ValueInStoreIsAbsent(*store()->GetAccountPrefStore(), kPrefName));
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetLocalPrefStore(), kPrefName, "pref-value"));
}

TEST_F(DualLayerUserPrefStoreTestWithoutUseSelectedTypes,
       ShouldAddPrefsToAccountStoreOnlyAfterEnabled) {
  store()->SetValue(kPrefName, base::Value("pref-value"), 0);

  // Pref is only added to the local pref store.
  EXPECT_TRUE(ValueInStoreIsAbsent(*store()->GetAccountPrefStore(), kPrefName));
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetLocalPrefStore(), kPrefName, "pref-value"));

  store()->EnableType(syncer::PREFERENCES);
  // The pref is not copied to the account store on enable.
  EXPECT_TRUE(ValueInStoreIsAbsent(*store()->GetAccountPrefStore(), kPrefName));

  store()->SetValue(kPrefName, base::Value("new_value"), 0);
  // Both stores are updated now.
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetAccountPrefStore(), kPrefName, "new_value"));
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetLocalPrefStore(), kPrefName, "new_value"));
}

TEST_F(DualLayerUserPrefStoreTestWithoutUseSelectedTypes,
       ShouldNotSetAccountValueForNotActiveTypesIfNotAlreadyExists) {
  ASSERT_TRUE(ValueInStoreIsAbsent(*account_store(), kPrefName));

  // Preferences sync is toggled on.
  store()->SetUserSelectedTypesForTest(
      {syncer::UserSelectableType::kPreferences});
  // PREFERENCES type is not active.
  ASSERT_EQ(0u, store()->GetActiveTypesForTest().count(syncer::PREFERENCES));

  // `kPrefName` is not set to the account store since PREFERENCES type is not
  // active and the pref does not already exist in the account store.
  {
    store()->SetValue(kPrefName, base::Value("new_value1"), 0);
    EXPECT_TRUE(ValueInStoreIsAbsent(*account_store(), kPrefName));
  }
  {
    store()->SetValueSilently(kPrefName, base::Value("new_value2"), 0);
    EXPECT_TRUE(ValueInStoreIsAbsent(*account_store(), kPrefName));
  }
  {
    base::Value* value = nullptr;
    ASSERT_TRUE(store()->GetMutableValue(kPrefName, &value));
    *value = base::Value("new_value3");
    store()->ReportValueChanged(kPrefName, 0);
    EXPECT_TRUE(ValueInStoreIsAbsent(*account_store(), kPrefName));
  }
}

class DualLayerUserPrefStoreTestWithUseSelectedTypes
    : public DualLayerUserPrefStoreTestForTypes {
 private:
  base::test::ScopedFeatureList feature_list_{
      syncer::kSyncPreferencesUseSelectedTypes};
};

TEST_F(DualLayerUserPrefStoreTestWithUseSelectedTypes,
       ShouldAddPrefsToAccountStoreIfPrefsIsToggledOn) {
  // Preferences sync is toggled on.
  store()->SetUserSelectedTypesForTest(
      {syncer::UserSelectableType::kPreferences});

  // Enable only PRIORITY_PREFERENCES
  store()->EnableType(syncer::PRIORITY_PREFERENCES);
  ASSERT_THAT(store()->GetActiveTypesForTest(),
              testing::ElementsAre(syncer::PRIORITY_PREFERENCES));

  store()->SetValue(kPriorityPrefName, base::Value("priority-value"), 0);
  store()->SetValue(kPrefName, base::Value("pref-value"), 0);

  ASSERT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(), kPriorityPrefName,
                             "priority-value"));
  // Regular pref is added to the account store even though it is not active
  // yet.
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetAccountPrefStore(), kPrefName, "pref-value"));
}

TEST_F(DualLayerUserPrefStoreTestWithUseSelectedTypes,
       ShouldAddPrefsToAccountStoreOnlyAfterSelected) {
  // Preferences sync is toggled off.
  store()->SetUserSelectedTypesForTest({});

  store()->SetValue(kPrefName, base::Value("value"), 0);

  // Pref is only added to the local pref store.
  EXPECT_TRUE(ValueInStoreIsAbsent(*store()->GetAccountPrefStore(), kPrefName));
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetLocalPrefStore(), kPrefName, "value"));

  // Preferences sync is toggled on.
  store()->SetUserSelectedTypesForTest(
      {syncer::UserSelectableType::kPreferences});
  // The pref is not copied to the account store on enable.
  EXPECT_TRUE(ValueInStoreIsAbsent(*store()->GetAccountPrefStore(), kPrefName));

  store()->SetValue(kPrefName, base::Value("new_value"), 0);
  // Both stores are updated now.
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetAccountPrefStore(), kPrefName, "new_value"));
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetLocalPrefStore(), kPrefName, "new_value"));
}

TEST_F(DualLayerUserPrefStoreTestWithUseSelectedTypes,
       ShouldSetAccountValueForNotActiveTypesIfNotAlreadyExists) {
  ASSERT_TRUE(ValueInStoreIsAbsent(*account_store(), kPrefName));

  // Preferences sync is toggled on.
  store()->SetUserSelectedTypesForTest(
      {syncer::UserSelectableType::kPreferences});
  // PREFERENCES type is not active.
  ASSERT_EQ(0u, store()->GetActiveTypesForTest().count(syncer::PREFERENCES));

  // `kPrefName` is set in the account store even though PREFERENCES type is not
  // active and the pref does not already exist in the account store.
  {
    store()->SetValue(kPrefName, base::Value("new_value1"), 0);
    EXPECT_TRUE(ValueInStoreIs(*account_store(), kPrefName, "new_value1"));
  }
  {
    store()->SetValueSilently(kPrefName, base::Value("new_value2"), 0);
    EXPECT_TRUE(ValueInStoreIs(*account_store(), kPrefName, "new_value2"));
  }
  {
    base::Value* value = nullptr;
    ASSERT_TRUE(store()->GetMutableValue(kPrefName, &value));
    *value = base::Value("new_value3");
    store()->ReportValueChanged(kPrefName, 0);
    EXPECT_TRUE(ValueInStoreIs(*account_store(), kPrefName, "new_value3"));
  }
}

TEST_F(DualLayerUserPrefStoreTestWithUseSelectedTypes,
       ShouldSetAccountValueForToggledOffTypesIfAlreadyExists) {
  // Preferences sync is off.
  store()->SetUserSelectedTypesForTest({});

  // Set pre-existing account pref value.
  account_store()->SetValue(kPref1, base::Value("value"), 0);
  // Account pref value is still read.
  EXPECT_TRUE(ValueInStoreIs(*store(), kPref1, "value"));

  store()->SetValue(kPref1, base::Value("new_value"), 0);
  store()->SetValue(kPref2, base::Value("new_value2"), 0);
  // The new value is still written to the account store for `kPref1` even
  // though preferences sync is off.
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetAccountPrefStore(), kPref1, "new_value"));
  // The same is not true for `kPref2` since it is not already present in the
  // account store.
  EXPECT_TRUE(ValueInStoreIsAbsent(*store()->GetAccountPrefStore(), kPref2));
}

#if BUILDFLAG(IS_CHROMEOS)
// Test to verify that the user selected OS types are loaded from a pref in the
// local store.
TEST_F(DualLayerUserPrefStoreTestWithUseSelectedTypes,
       ShouldGetUserSelectedOsTypesFromLocalStore) {
  // Multiple types.
  local_store()->SetValueSilently(kUserSelectedOsTypesPrefName,
                                  base::Value(base::Value::List()
                                                  .Append("passwords")
                                                  .Append("osPreferences")
                                                  .Append("osApps")),
                                  0);
  // Only the interesting type (osPreferences) is returned.
  EXPECT_EQ(store()->GetUserSelectedOsTypesForTest(),
            syncer::UserSelectableOsTypeSet(
                {syncer::UserSelectableOsType::kOsPreferences}));

  // Empty list.
  local_store()->SetValueSilently(kUserSelectedOsTypesPrefName,
                                  base::Value(base::Value::List()), 0);
  EXPECT_TRUE(store()->GetUserSelectedOsTypesForTest().empty());
}

// Test to verify that the user selected OS types are stored in a pref in the
// local store.
TEST_F(DualLayerUserPrefStoreTestWithUseSelectedTypes,
       ShouldSetUserSelectedOsTypesToLocalStore) {
  // Multiple types.
  store()->SetUserSelectedOsTypesForTest(syncer::UserSelectableOsTypeSet(
      {syncer::UserSelectableOsType::kOsPreferences}));
  EXPECT_TRUE(
      ValueInStoreIs(*local_store(), kUserSelectedOsTypesPrefName,
                     base::Value(base::Value::List().Append("osPreferences"))));
  EXPECT_TRUE(
      ValueInStoreIsAbsent(*account_store(), kUserSelectedOsTypesPrefName));

  // Empty list.
  store()->SetUserSelectedOsTypesForTest(syncer::UserSelectableOsTypeSet());
  EXPECT_TRUE(ValueInStoreIs(*local_store(), kUserSelectedOsTypesPrefName,
                             base::Value(base::Value::List())));
}

// Test to verify that OS prefs are added to the account store only if the OS
// preferences type is enabled.
TEST_F(DualLayerUserPrefStoreTestWithUseSelectedTypes,
       ShouldAddOsPrefsToAccountStoreIfOsPrefsIsToggledOn) {
  // OS Preferences sync is toggled on.
  store()->SetUserSelectedOsTypesForTest(
      {syncer::UserSelectableOsType::kOsPreferences});

  // Enable only OS_PRIORITY_PREFERENCES
  store()->EnableType(syncer::OS_PRIORITY_PREFERENCES);
  ASSERT_THAT(store()->GetActiveTypesForTest(),
              testing::ElementsAre(syncer::OS_PRIORITY_PREFERENCES));

  store()->SetValue(kOsPriorityPrefName, base::Value("priority-value"), 0);
  store()->SetValue(kOsPrefName, base::Value("pref-value"), 0);

  ASSERT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(),
                             kOsPriorityPrefName, "priority-value"));
  // Regular pref is added to the account store even though it is not active
  // yet.
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(), kOsPrefName,
                             "pref-value"));
}

TEST_F(DualLayerUserPrefStoreTestWithUseSelectedTypes,
       ShouldNotAddOsPrefsToAccountStoreIfOsPrefsIsToggledOff) {
  // OS Preferences sync is toggled off.
  store()->SetUserSelectedOsTypesForTest({});

  // Enable only OS_PRIORITY_PREFERENCES
  store()->EnableType(syncer::OS_PRIORITY_PREFERENCES);
  ASSERT_THAT(store()->GetActiveTypesForTest(),
              testing::ElementsAre(syncer::OS_PRIORITY_PREFERENCES));

  store()->SetValue(kOsPriorityPrefName, base::Value("priority-value"), 0);
  store()->SetValue(kOsPrefName, base::Value("pref-value"), 0);

  // OS prefs are not added to the account store since the OS pref type is
  // disabled, they are only added to the local pref store.
  ASSERT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kOsPriorityPrefName,
                             "priority-value"));
  EXPECT_TRUE(ValueInStoreIsAbsent(*store()->GetAccountPrefStore(),
                                   kOsPriorityPrefName));
  ASSERT_TRUE(
      ValueInStoreIs(*store()->GetLocalPrefStore(), kOsPrefName, "pref-value"));
  EXPECT_TRUE(
      ValueInStoreIsAbsent(*store()->GetAccountPrefStore(), kOsPrefName));
}
#endif  // BUILDFLAG(IS_CHROMEOS)

class MergeTestPrefModelAssociatorClient : public PrefModelAssociatorClient {
 public:
  MergeTestPrefModelAssociatorClient()
      : syncable_prefs_database_(kSyncablePrefsDatabase) {}

  // PrefModelAssociatorClient implementation.
  base::Value MaybeMergePreferenceValues(
      std::string_view pref_name,
      const base::Value& local_value,
      const base::Value& server_value) const override {
    if (auto it = custom_merge_values_.find(pref_name);
        it != custom_merge_values_.end()) {
      return it->second.Clone();
    }
    return base::Value();
  }

  const SyncablePrefsDatabase& GetSyncablePrefsDatabase() const override {
    return syncable_prefs_database_;
  }

  void SetCustomMergeValue(const std::string& pref_name, base::Value value) {
    custom_merge_values_[pref_name] = std::move(value);
  }

 private:
  ~MergeTestPrefModelAssociatorClient() override = default;

  TestSyncablePrefsDatabase syncable_prefs_database_;

  std::set<std::string> mergeable_dict_prefs_;
  std::set<std::string> mergeable_list_prefs_;
  std::map<std::string, base::Value, std::less<>> custom_merge_values_;
};

class DualLayerUserPrefStoreMergeTest : public testing::Test {
 public:
  DualLayerUserPrefStoreMergeTest() {
    local_store_ = base::MakeRefCounted<TestingPrefStore>();
    account_store_ = base::MakeRefCounted<TestingPrefStore>();
    pref_model_associator_client_ =
        base::MakeRefCounted<MergeTestPrefModelAssociatorClient>();
    dual_layer_store_ = base::MakeRefCounted<DualLayerUserPrefStore>(
        local_store_, account_store_, pref_model_associator_client_);

    local_store_->NotifyInitializationCompleted();
    account_store_->NotifyInitializationCompleted();

    dual_layer_store_->AddObserver(&observer_);

    // Set preferences user selected type by default.
    // TODO(crbug.com/464008640): Also set kOsPreferences for
    // OS_{,PRIORITY_}PREFERENCES.
    dual_layer_store_->SetUserSelectedTypesForTest(
        {syncer::UserSelectableType::kPreferences});
    dual_layer_store_->EnableType(syncer::PREFERENCES);
    dual_layer_store_->EnableType(syncer::PRIORITY_PREFERENCES);
#if BUILDFLAG(IS_CHROMEOS)
    dual_layer_store_->EnableType(syncer::OS_PREFERENCES);
    dual_layer_store_->EnableType(syncer::OS_PRIORITY_PREFERENCES);
#endif  // BUILDFLAG(IS_CHROMEOS)
  }

  ~DualLayerUserPrefStoreMergeTest() override {
    dual_layer_store_->RemoveObserver(&observer_);
  }

  DualLayerUserPrefStore* store() { return dual_layer_store_.get(); }

 protected:
  scoped_refptr<TestingPrefStore> local_store_;
  scoped_refptr<TestingPrefStore> account_store_;
  scoped_refptr<MergeTestPrefModelAssociatorClient>
      pref_model_associator_client_;
  scoped_refptr<DualLayerUserPrefStore> dual_layer_store_;
  testing::StrictMock<MockPrefStoreObserver> observer_;
};

TEST_F(DualLayerUserPrefStoreMergeTest,
       ShouldUseAccountValueForNonMergeablePrefs) {
  // String prefs.
  base::Value account_value("account_value");
  store()->GetAccountPrefStore()->SetValueSilently(kPref1,
                                                   account_value.Clone(), 0);
  base::Value local_value("local_value");
  store()->GetLocalPrefStore()->SetValueSilently(kPref1, local_value.Clone(),
                                                 0);

  // Different values are set in both stores; the one from the account should
  // take precedence.
  // Uses GetValue().
  {
    const base::Value* result = nullptr;
    ASSERT_TRUE(store()->GetValue(kPref1, &result));
    EXPECT_EQ(*result, account_value);
  }
  // Uses GetMutableValue().
  {
    base::Value* result = nullptr;
    ASSERT_TRUE(store()->GetMutableValue(kPref1, &result));
    EXPECT_EQ(*result, account_value);
  }
  // Uses GetValues().
  {
    EXPECT_TRUE(
        ValueInDictByDottedPathIs(store()->GetValues(), kPref1, account_value));
  }

  // List prefs.

  base::Value account_list(base::Value::List().Append("account_value"));
  store()->GetAccountPrefStore()->SetValueSilently(kPref2, account_list.Clone(),
                                                   0);
  base::Value local_list(base::Value::List().Append("local_value"));
  store()->GetLocalPrefStore()->SetValueSilently(kPref2, local_list.Clone(), 0);

  // Different values are set in both stores; the one from the account should
  // take precedence.
  // Uses GetValue().
  {
    const base::Value* result = nullptr;
    ASSERT_TRUE(store()->GetValue(kPref2, &result));
    EXPECT_EQ(*result, account_list);
  }
  // Uses GetMutableValue().
  {
    base::Value* result = nullptr;
    ASSERT_TRUE(store()->GetMutableValue(kPref2, &result));
    EXPECT_EQ(*result, account_list);
  }
  // Uses GetValues().
  {
    EXPECT_TRUE(
        ValueInDictByDottedPathIs(store()->GetValues(), kPref2, account_list));
  }

  // Dictionary prefs.

  base::Value account_dict(base::Value::Dict()
                               .Set("account_key", "account_value")
                               .Set("common_key", "account_value"));
  store()->GetAccountPrefStore()->SetValueSilently(kPref3, account_dict.Clone(),
                                                   0);
  base::Value local_dict(base::Value::Dict()
                             .Set("local_key", "local_value")
                             .Set("common_key", "local_value"));
  store()->GetLocalPrefStore()->SetValueSilently(kPref3, local_dict.Clone(), 0);

  // Different values are set in both stores; the one from the account should
  // take precedence.
  // Uses GetValue().
  {
    const base::Value* result = nullptr;
    ASSERT_TRUE(store()->GetValue(kPref3, &result));
    EXPECT_EQ(*result, account_dict);
  }
  // Uses GetMutableValue().
  {
    base::Value* result = nullptr;
    ASSERT_TRUE(store()->GetMutableValue(kPref3, &result));
    EXPECT_EQ(*result, account_dict);
  }
  // Uses GetValues().
  {
    EXPECT_TRUE(
        ValueInDictByDottedPathIs(store()->GetValues(), kPref3, account_dict));
  }
  // The local and the account stores are left untouched.
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetLocalPrefStore(), kPref1, local_value));
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetAccountPrefStore(), kPref1, account_value));
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetLocalPrefStore(), kPref2, local_list));
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetAccountPrefStore(), kPref2, account_list));
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetLocalPrefStore(), kPref3, local_dict));
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetAccountPrefStore(), kPref3, account_dict));
}

TEST_F(DualLayerUserPrefStoreMergeTest, ShouldMergeMergeableListPref) {
  base::Value account_list(
      base::Value::List().Append("account_value").Append("common_value"));
  store()->GetAccountPrefStore()->SetValueSilently(kMergeableListPref,
                                                   account_list.Clone(), 0);
  base::Value local_list(
      base::Value::List().Append("local_value").Append("common_value"));
  store()->GetLocalPrefStore()->SetValueSilently(kMergeableListPref,
                                                 local_list.Clone(), 0);

  // Different values are set in both stores; a merged view should be returned.
  // The two lists should be de-duped, with account values coming first.
  base::Value merged_list(base::Value::List()
                              .Append("account_value")
                              .Append("common_value")
                              .Append("local_value"));

  // Uses GetValue().
  {
    const base::Value* result = nullptr;
    ASSERT_TRUE(store()->GetValue(kMergeableListPref, &result));
    EXPECT_EQ(*result, merged_list);
  }
  // Uses GetMutableValue().
  {
    base::Value* result = nullptr;
    ASSERT_TRUE(store()->GetMutableValue(kMergeableListPref, &result));
    EXPECT_EQ(*result, merged_list);
  }
  // Uses GetValues().
  {
    EXPECT_TRUE(ValueInDictByDottedPathIs(store()->GetValues(),
                                          kMergeableListPref, merged_list));
  }

  // The local and the account stores are left untouched.
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kMergeableListPref,
                             local_list));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(),
                             kMergeableListPref, account_list));
}

TEST_F(DualLayerUserPrefStoreMergeTest, ShouldMergeMergeableDictPref) {
  base::Value account_dict(base::Value::Dict()
                               .Set("account_key", "account_value")
                               .Set("common_key", "account_value"));
  store()->GetAccountPrefStore()->SetValueSilently(kMergeableDictPref1,
                                                   account_dict.Clone(), 0);
  base::Value local_dict(base::Value::Dict()
                             .Set("local_key", "local_value")
                             .Set("common_key", "local_value"));
  store()->GetLocalPrefStore()->SetValueSilently(kMergeableDictPref1,
                                                 local_dict.Clone(), 0);

  // Different values are set in both stores; a merged view should be returned.
  // In case of conflict, the value in account store takes precedence.
  base::Value merged_dict(base::Value::Dict()
                              .Set("account_key", "account_value")
                              .Set("local_key", "local_value")
                              .Set("common_key", "account_value"));
  // Uses GetValue().
  {
    const base::Value* result = nullptr;
    ASSERT_TRUE(store()->GetValue(kMergeableDictPref1, &result));
    EXPECT_EQ(*result, merged_dict);
  }
  // Uses GetMutableValue().
  {
    base::Value* result = nullptr;
    ASSERT_TRUE(store()->GetMutableValue(kMergeableDictPref1, &result));
    EXPECT_EQ(*result, merged_dict);
  }
  // Uses GetValues().
  {
    EXPECT_TRUE(ValueInDictByDottedPathIs(store()->GetValues(),
                                          kMergeableDictPref1, merged_dict));
  }

  // The local and the account stores are left untouched.
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kMergeableDictPref1,
                             local_dict));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(),
                             kMergeableDictPref1, account_dict));
}

TEST_F(DualLayerUserPrefStoreMergeTest, ShouldMergeSpecialCasedMergeablePref) {
  base::Value account_value("account_value");
  store()->GetAccountPrefStore()->SetValueSilently(kCustomMergePref,
                                                   account_value.Clone(), 0);
  base::Value local_value("local_value");
  store()->GetLocalPrefStore()->SetValueSilently(kCustomMergePref,
                                                 local_value.Clone(), 0);

  base::Value merged_value("custom_merge_value");
  pref_model_associator_client_->SetCustomMergeValue(kCustomMergePref,
                                                     merged_value.Clone());
  // Different values are set in both stores; the merge should use the custom
  // logic.
  // Uses GetValue().
  {
    const base::Value* result = nullptr;
    ASSERT_TRUE(store()->GetValue(kCustomMergePref, &result));
    EXPECT_EQ(*result, merged_value);
  }
  // Uses GetMutableValue().
  {
    base::Value* result = nullptr;
    ASSERT_TRUE(store()->GetMutableValue(kCustomMergePref, &result));
    EXPECT_EQ(*result, merged_value);
  }
  // Uses GetValues().
  {
    EXPECT_TRUE(ValueInDictByDottedPathIs(store()->GetValues(),
                                          kCustomMergePref, merged_value));
  }

  // The local and the account stores are left untouched.
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kCustomMergePref,
                             local_value));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(), kCustomMergePref,
                             account_value));
}

TEST_F(DualLayerUserPrefStoreMergeTest,
       ShouldApplyUpdatesToBothStoresForNonMergeablePrefOnSetValue) {
  // Set three prefs; one only in the account store, one only in the local store
  // and one in both stores.
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref1, base::Value("account_value1"), 0);
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref2, base::Value("local_value2"), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref3, base::Value("account_value3"), 0);
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref3, base::Value("local_value3"), 0);

  // Set an existing account pref. This should not raise a notification, but
  // only writes to the local store.
  store()->SetValue(kPref1, base::Value("account_value1"), 0);
  EXPECT_TRUE(ValueInStoreIs(*store(), kPref1, base::Value("account_value1")));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kPref1,
                             base::Value("account_value1")));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(), kPref1,
                             base::Value("account_value1")));

  // Set an existing local pref. This should write to the account store, but not
  // raise a notification.
  store()->SetValue(kPref2, base::Value("local_value2"), 0);
  EXPECT_TRUE(ValueInStoreIs(*store(), kPref2, base::Value("local_value2")));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kPref2,
                             base::Value("local_value2")));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(), kPref2,
                             base::Value("local_value2")));

  // Update the common pref. This writes to both stores and raises notification
  // because the effective value changed.
  EXPECT_CALL(observer_, OnPrefValueChanged(kPref3));
  store()->SetValue(kPref3, base::Value("new_value3"), 0);
  EXPECT_TRUE(ValueInStoreIs(*store(), kPref3, base::Value("new_value3")));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kPref3,
                             base::Value("new_value3")));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(), kPref3,
                             base::Value("new_value3")));
}

TEST_F(DualLayerUserPrefStoreMergeTest,
       ShouldApplyUpdatesToBothStoresForNonMergeablePrefOnSetValueSilently) {
  // Set three prefs; one only in the account store, one only in the local store
  // and one in both stores.
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref1, base::Value("account_value1"), 0);
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref2, base::Value("local_value2"), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref3, base::Value("account_value3"), 0);
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref3, base::Value("local_value3"), 0);

  // Set an existing account pref. This should write to the local store.
  store()->SetValueSilently(kPref1, base::Value("account_value1"), 0);
  EXPECT_TRUE(ValueInStoreIs(*store(), kPref1, base::Value("account_value1")));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kPref1,
                             base::Value("account_value1")));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(), kPref1,
                             base::Value("account_value1")));

  // Set an existing local pref. This should write to the account store.
  store()->SetValueSilently(kPref2, base::Value("local_value2"), 0);
  EXPECT_TRUE(ValueInStoreIs(*store(), kPref2, base::Value("local_value2")));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kPref2,
                             base::Value("local_value2")));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(), kPref2,
                             base::Value("local_value2")));

  // Update the common pref. This writes to both stores.
  store()->SetValueSilently(kPref3, base::Value("new_value3"), 0);
  EXPECT_TRUE(ValueInStoreIs(*store(), kPref3, base::Value("new_value3")));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kPref3,
                             base::Value("new_value3")));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(), kPref3,
                             base::Value("new_value3")));
}

TEST_F(DualLayerUserPrefStoreMergeTest,
       ShouldApplyUpdatesToBothStoresForNonMergeablePrefOnReportValueChanged) {
  // Set three prefs; one only in the account store, one only in the local store
  // and one in both stores.
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref1, base::Value("account_value1"), 0);
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref2, base::Value("local_value2"), 0);
  store()->GetAccountPrefStore()->SetValueSilently(
      kPref3, base::Value("account_value3"), 0);
  store()->GetLocalPrefStore()->SetValueSilently(
      kPref3, base::Value("local_value3"), 0);

  // Set an existing account pref. This writes to both stores and raises
  // notification.
  EXPECT_CALL(observer_, OnPrefValueChanged(kPref1));
  store()->ReportValueChanged(kPref1, 0);
  EXPECT_TRUE(ValueInStoreIs(*store(), kPref1, base::Value("account_value1")));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kPref1,
                             base::Value("account_value1")));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(), kPref1,
                             base::Value("account_value1")));

  // Set an existing local pref. This writes to both stores and raises
  // notification.
  EXPECT_CALL(observer_, OnPrefValueChanged(kPref2));
  store()->ReportValueChanged(kPref2, 0);
  EXPECT_TRUE(ValueInStoreIs(*store(), kPref2, base::Value("local_value2")));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kPref2,
                             base::Value("local_value2")));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(), kPref2,
                             base::Value("local_value2")));

  // Update the common pref. This writes to both stores and raises notification.
  EXPECT_CALL(observer_, OnPrefValueChanged(kPref3));
  store()->ReportValueChanged(kPref3, 0);
  EXPECT_TRUE(ValueInStoreIs(*store(), kPref3, base::Value("account_value3")));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kPref3,
                             base::Value("account_value3")));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(), kPref3,
                             base::Value("account_value3")));
}

TEST_F(DualLayerUserPrefStoreMergeTest,
       ShouldUpdateMergedPrefOnWriteToUnderlyingStoresUsingSetValue) {
  store()->GetAccountPrefStore()->SetValueSilently(
      kMergeableDictPref1,
      base::Value(base::Value::Dict()
                      .Set("account_key", "account_value")
                      .Set("common_key", "account_value")),
      0);
  store()->GetLocalPrefStore()->SetValueSilently(
      kMergeableDictPref1,
      base::Value(base::Value::Dict()
                      .Set("local_key", "local_value")
                      .Set("common_key", "local_value")),
      0);

  ASSERT_TRUE(
      ValueInStoreIs(*store(), kMergeableDictPref1,
                     base::Value(base::Value::Dict()
                                     .Set("account_key", "account_value")
                                     .Set("local_key", "local_value")
                                     .Set("common_key", "account_value"))));

  EXPECT_CALL(observer_, OnPrefValueChanged(kMergeableDictPref1));
  // Update account value.
  store()->GetAccountPrefStore()->SetValue(
      kMergeableDictPref1,
      base::Value(base::Value::Dict()
                      .Set("account_key", "new_account_value")
                      .Set("common_key", "account_value")),
      0);

  // Updated account value should reflect in the merged view.
  EXPECT_TRUE(
      ValueInStoreIs(*store(), kMergeableDictPref1,
                     base::Value(base::Value::Dict()
                                     // Updated value.
                                     .Set("account_key", "new_account_value")
                                     .Set("local_key", "local_value")
                                     .Set("common_key", "account_value"))));

  EXPECT_CALL(observer_, OnPrefValueChanged(kMergeableDictPref1));
  // Add new key to local value.
  store()->GetLocalPrefStore()->SetValue(
      kMergeableDictPref1,
      base::Value(base::Value::Dict()
                      .Set("local_key", "local_value")
                      // New entry.
                      .Set("new_local_key", "local_value")
                      .Set("common_key", "local_value")),
      0);

  // Updated local value should reflect in the merged view.
  EXPECT_TRUE(
      ValueInStoreIs(*store(), kMergeableDictPref1,
                     base::Value(base::Value::Dict()
                                     .Set("account_key", "new_account_value")
                                     .Set("local_key", "local_value")
                                     // New entry.
                                     .Set("new_local_key", "local_value")
                                     .Set("common_key", "account_value"))));
}

TEST_F(DualLayerUserPrefStoreMergeTest,
       ShouldUpdateMergedPrefOnWriteToUnderlyingStoresUsingSetValueSilently) {
  store()->GetAccountPrefStore()->SetValueSilently(
      kMergeableDictPref1,
      base::Value(base::Value::Dict()
                      .Set("account_key", "account_value")
                      .Set("common_key", "account_value")),
      0);
  store()->GetLocalPrefStore()->SetValueSilently(
      kMergeableDictPref1,
      base::Value(base::Value::Dict()
                      .Set("local_key", "local_value")
                      .Set("common_key", "local_value")),
      0);

  ASSERT_TRUE(
      ValueInStoreIs(*store(), kMergeableDictPref1,
                     base::Value(base::Value::Dict()
                                     .Set("account_key", "account_value")
                                     .Set("local_key", "local_value")
                                     .Set("common_key", "account_value"))));

  // Update account value.
  store()->GetAccountPrefStore()->SetValueSilently(
      kMergeableDictPref1,
      base::Value(base::Value::Dict()
                      // Updated value.
                      .Set("account_key", "new_account_value")
                      .Set("common_key", "account_value")),
      0);

  // Updated account value should reflect in the merged view.
  EXPECT_TRUE(
      ValueInStoreIs(*store(), kMergeableDictPref1,
                     base::Value(base::Value::Dict()
                                     // Updated value.
                                     .Set("account_key", "new_account_value")
                                     .Set("local_key", "local_value")
                                     .Set("common_key", "account_value"))));

  // Add new key to local value.
  store()->GetLocalPrefStore()->SetValueSilently(
      kMergeableDictPref1,
      base::Value(base::Value::Dict()
                      .Set("local_key", "local_value")
                      .Set("new_local_key", "local_value")
                      .Set("common_key", "local_value")),
      0);

  // Updated local value should reflect in the merged view.
  EXPECT_TRUE(
      ValueInStoreIs(*store(), kMergeableDictPref1,
                     base::Value(base::Value::Dict()
                                     .Set("account_key", "new_account_value")
                                     .Set("local_key", "local_value")
                                     // New entry.
                                     .Set("new_local_key", "local_value")
                                     .Set("common_key", "account_value"))));
}

TEST_F(DualLayerUserPrefStoreMergeTest,
       ShouldUpdateMergedPrefOnWriteToUnderlyingStoresUsingMutableValue) {
  store()->GetAccountPrefStore()->SetValueSilently(
      kMergeableDictPref1,
      base::Value(base::Value::Dict()
                      .Set("account_key", "account_value")
                      .Set("common_key", "account_value")),
      0);
  store()->GetLocalPrefStore()->SetValueSilently(
      kMergeableDictPref1,
      base::Value(base::Value::Dict()
                      .Set("local_key", "local_value")
                      .Set("common_key", "local_value")),
      0);

  ASSERT_TRUE(
      ValueInStoreIs(*store(), kMergeableDictPref1,
                     base::Value(base::Value::Dict()
                                     .Set("account_key", "account_value")
                                     .Set("local_key", "local_value")
                                     .Set("common_key", "account_value"))));

  base::Value* account_value = nullptr;
  store()->GetAccountPrefStore()->GetMutableValue(kMergeableDictPref1,
                                                  &account_value);
  ASSERT_TRUE(account_value && account_value->is_dict());

  // Update account value.
  *account_value = base::Value(base::Value::Dict()
                                   // Updated value.
                                   .Set("account_key", "new_account_value")
                                   .Set("common_key", "account_value"));

  EXPECT_CALL(observer_, OnPrefValueChanged(kMergeableDictPref1));
  store()->GetAccountPrefStore()->ReportValueChanged(kMergeableDictPref1, 0);

  // Updated account value should reflect in the merged view.
  EXPECT_TRUE(
      ValueInStoreIs(*store(), kMergeableDictPref1,
                     base::Value(base::Value::Dict()
                                     // Updated value.
                                     .Set("account_key", "new_account_value")
                                     .Set("local_key", "local_value")
                                     .Set("common_key", "account_value"))));

  base::Value* local_value = nullptr;
  store()->GetLocalPrefStore()->GetMutableValue(kMergeableDictPref1,
                                                &local_value);
  ASSERT_TRUE(local_value && local_value->is_dict());
  // Add new key to local value.
  local_value->GetDict().Set("new_local_key", "local_value");

  EXPECT_CALL(observer_, OnPrefValueChanged(kMergeableDictPref1));
  store()->GetLocalPrefStore()->ReportValueChanged(kMergeableDictPref1, 0);

  // Updated local value should reflect in the merged view.
  EXPECT_TRUE(
      ValueInStoreIs(*store(), kMergeableDictPref1,
                     base::Value(base::Value::Dict()
                                     .Set("account_key", "new_account_value")
                                     .Set("local_key", "local_value")
                                     // New entry.
                                     .Set("new_local_key", "local_value")
                                     .Set("common_key", "account_value"))));
}

TEST_F(DualLayerUserPrefStoreMergeTest,
       ShouldUpdateMergedPrefOnRemoveFromUnderlyingStores) {
  store()->GetAccountPrefStore()->SetValueSilently(
      kMergeableDictPref1,
      base::Value(base::Value::Dict()
                      .Set("account_key", "account_value")
                      .Set("common_key", "account_value")),
      0);
  store()->GetLocalPrefStore()->SetValueSilently(
      kMergeableDictPref1,
      base::Value(base::Value::Dict()
                      .Set("local_key", "local_value")
                      .Set("common_key", "local_value")),
      0);

  ASSERT_TRUE(
      ValueInStoreIs(*store(), kMergeableDictPref1,
                     base::Value(base::Value::Dict()
                                     .Set("account_key", "account_value")
                                     .Set("local_key", "local_value")
                                     .Set("common_key", "account_value"))));

  // Remove pref from the account store.
  store()->GetAccountPrefStore()->RemoveValuesByPrefixSilently(
      kMergeableDictPref1);
  EXPECT_TRUE(
      ValueInStoreIs(*store(), kMergeableDictPref1,
                     base::Value(base::Value::Dict()
                                     .Set("local_key", "local_value")
                                     // Value now being by the local store.
                                     .Set("common_key", "local_value"))));

  // Remove pref from the local store.
  EXPECT_CALL(observer_, OnPrefValueChanged(kMergeableDictPref1));
  store()->GetLocalPrefStore()->RemoveValue(kMergeableDictPref1, 0);
  EXPECT_TRUE(ValueInStoreIsAbsent(*store(), kMergeableDictPref1));
}

TEST_F(DualLayerUserPrefStoreMergeTest, ShouldClearMergedPrefOnRemove) {
  // Ensures that pref no longer exists in the merged pref store upon remove.
  store()->GetAccountPrefStore()->SetValueSilently(
      kMergeableDictPref1,
      base::Value(base::Value::Dict()
                      .Set("account_key", "account_value")
                      .Set("common_key", "account_value")),
      0);
  store()->GetLocalPrefStore()->SetValueSilently(
      kMergeableDictPref1,
      base::Value(base::Value::Dict()
                      .Set("local_key", "local_value")
                      .Set("common_key", "local_value")),
      0);

  ASSERT_TRUE(
      ValueInStoreIs(*store(), kMergeableDictPref1,
                     base::Value(base::Value::Dict()
                                     .Set("account_key", "account_value")
                                     .Set("local_key", "local_value")
                                     .Set("common_key", "account_value"))));

  EXPECT_CALL(observer_, OnPrefValueChanged(kMergeableDictPref1));
  store()->RemoveValue(kMergeableDictPref1, 0);
  EXPECT_TRUE(ValueInStoreIsAbsent(*store(), kMergeableDictPref1));

  store()->GetAccountPrefStore()->SetValueSilently(
      kMergeableDictPref2,
      base::Value(base::Value::Dict()
                      .Set("account_key", "account_value")
                      .Set("common_key", "account_value")),
      0);
  store()->GetLocalPrefStore()->SetValueSilently(
      kMergeableDictPref2,
      base::Value(base::Value::Dict()
                      .Set("local_key", "local_value")
                      .Set("common_key", "local_value")),
      0);

  ASSERT_TRUE(
      ValueInStoreIs(*store(), kMergeableDictPref2,
                     base::Value(base::Value::Dict()
                                     .Set("account_key", "account_value")
                                     .Set("local_key", "local_value")
                                     .Set("common_key", "account_value"))));

  store()->RemoveValuesByPrefixSilently(kMergeableDictPref2);
  EXPECT_TRUE(ValueInStoreIsAbsent(*store(), kMergeableDictPref2));
}

TEST_F(DualLayerUserPrefStoreMergeTest,
       ShouldUnmergeMergeableDictPrefButNotAddUnchangedValueToAccountStore) {
  base::Value local_dict(base::Value::Dict().Set("local_key", "local_value"));
  store()->GetLocalPrefStore()->SetValueSilently(kMergeableDictPref1,
                                                 local_dict.Clone(), 0);

  // `kMergeableDictPref1` only exists in the local store.
  ASSERT_TRUE(ValueInStoreIsAbsent(*store()->GetAccountPrefStore(),
                                   kMergeableDictPref1));

  // Effective value same as local value since pref is not in account store.
  ASSERT_TRUE(ValueInStoreIs(*store(), kMergeableDictPref1, local_dict));

  // Set the effective/merged value again.
  // Note: Expecting no notification.
  store()->SetValue(kMergeableDictPref1, local_dict.Clone(), 0);

  // Value in the local store remains unchanged.
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kMergeableDictPref1,
                             local_dict));
  // An empty dict pref is added to the account store.
  // Note: This is an implementation detail. Ideally, not adding the pref to the
  // account store might be a better approach.
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(),
                             kMergeableDictPref1,
                             base::Value(base::Value::Type::DICT)));
}

TEST_F(DualLayerUserPrefStoreMergeTest,
       ShouldUnmergeMergeableDictPrefButNotAddUnchangedValueToLocalStore) {
  base::Value account_dict(
      base::Value::Dict().Set("account_key", "account_value"));
  store()->GetAccountPrefStore()->SetValueSilently(kMergeableDictPref1,
                                                   account_dict.Clone(), 0);
  // `kMergeableDictPref1` only exists in the account store.
  ASSERT_TRUE(
      ValueInStoreIsAbsent(*store()->GetLocalPrefStore(), kMergeableDictPref1));

  ASSERT_TRUE(ValueInStoreIs(*store(), kMergeableDictPref1, account_dict));

  // Set the effective/merged value again.
  // Note: Expecting no notification.
  store()->SetValue(kMergeableDictPref1, account_dict.Clone(), 0);

  // An empty dict pref is added to the local store.
  // Note: This is an implementation detail. Ideally, not adding the pref to the
  // local store might be a better approach.
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kMergeableDictPref1,
                             base::Value(base::Value::Type::DICT)));
  // Value in the account store remains unchanged.
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(),
                             kMergeableDictPref1, account_dict));
}

TEST_F(DualLayerUserPrefStoreMergeTest,
       ShouldUnmergeAndApplyUpdatesForMergeableDictPrefOnSetValue) {

  base::Value local_dict(base::Value::Dict()
                             .Set("local_key1", "local_value1")
                             .Set("local_key2", "local_value2")
                             .Set("local_key3", "local_value3")
                             .Set("common_key1", "local_value4")
                             .Set("common_key2", "common_value"));
  store()->GetLocalPrefStore()->SetValueSilently(kMergeableDictPref1,
                                                 local_dict.Clone(), 0);

  base::Value account_dict(base::Value::Dict()
                               .Set("account_key1", "account_value1")
                               .Set("account_key2", "account_value2")
                               .Set("account_key3", "account_value3")
                               .Set("common_key1", "account_value4")
                               .Set("common_key2", "common_value"));
  store()->GetAccountPrefStore()->SetValueSilently(kMergeableDictPref1,
                                                   account_dict.Clone(), 0);

  base::Value merged_dict(base::Value::Dict()
                              .Set("account_key1", "account_value1")
                              .Set("account_key2", "account_value2")
                              .Set("account_key3", "account_value3")
                              .Set("common_key1", "account_value4")
                              .Set("common_key2", "common_value")
                              .Set("local_key1", "local_value1")
                              .Set("local_key2", "local_value2")
                              .Set("local_key3", "local_value3"));
  ASSERT_TRUE(ValueInStoreIs(*store(), kMergeableDictPref1, merged_dict));

  base::Value updated_dict(base::Value::Dict()
                               // New key, should get added to both
                               // stores.
                               .Set("new_key", "new_value")
                               // Updated value, should get added to both
                               // stores.
                               .Set("account_key1", "new_value1")
                               // No change, should only be in account
                               // store.
                               .Set("account_key2", "account_value2")
                               // No change, should only be in local
                               // store.
                               .Set("local_key1", "local_value1")
                               // Updated value, should get added to both
                               // stores.
                               .Set("local_key2", "new_value2")
                               // Updated value, should get added to both
                               // stores.
                               .Set("common_key1", "local_value4")
                               // Updated value, should get added to both
                               // stores.
                               .Set("common_key2", "new_common_value"));
  EXPECT_CALL(observer_, OnPrefValueChanged(kMergeableDictPref1));
  store()->SetValue(kMergeableDictPref1, updated_dict.Clone(), 0);

  // Note: "local_key3" has been deleted.
  base::Value updated_local_dict(base::Value::Dict()
                                     .Set("new_key", "new_value")
                                     .Set("account_key1", "new_value1")
                                     .Set("local_key1", "local_value1")
                                     .Set("local_key2", "new_value2")
                                     .Set("common_key1", "local_value4")
                                     .Set("common_key2", "new_common_value"));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kMergeableDictPref1,
                             updated_local_dict));

  // Note: "account_key3" has been deleted.
  base::Value updated_account_dict(base::Value::Dict()
                                       .Set("new_key", "new_value")
                                       .Set("account_key1", "new_value1")
                                       .Set("account_key2", "account_value2")
                                       .Set("local_key2", "new_value2")
                                       .Set("common_key1", "local_value4")
                                       .Set("common_key2", "new_common_value"));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(),
                             kMergeableDictPref1, updated_account_dict));

  ASSERT_TRUE(ValueInStoreIs(*store(), kMergeableDictPref1, updated_dict));
}

TEST_F(DualLayerUserPrefStoreMergeTest,
       ShouldUnmergeAndApplyUpdatesForMergeableDictPrefOnSetValueSilently) {

  base::Value local_dict(base::Value::Dict()
                             .Set("local_key1", "local_value1")
                             .Set("local_key2", "local_value2")
                             .Set("local_key3", "local_value3")
                             .Set("common_key1", "local_value4")
                             .Set("common_key2", "common_value"));
  store()->GetLocalPrefStore()->SetValueSilently(kMergeableDictPref1,
                                                 local_dict.Clone(), 0);

  base::Value account_dict(base::Value::Dict()
                               .Set("account_key1", "account_value1")
                               .Set("account_key2", "account_value2")
                               .Set("account_key3", "account_value3")
                               .Set("common_key1", "account_value4")
                               .Set("common_key2", "common_value"));
  store()->GetAccountPrefStore()->SetValueSilently(kMergeableDictPref1,
                                                   account_dict.Clone(), 0);

  base::Value merged_dict(base::Value::Dict()
                              .Set("account_key1", "account_value1")
                              .Set("account_key2", "account_value2")
                              .Set("account_key3", "account_value3")
                              .Set("common_key1", "account_value4")
                              .Set("common_key2", "common_value")
                              .Set("local_key1", "local_value1")
                              .Set("local_key2", "local_value2")
                              .Set("local_key3", "local_value3"));
  ASSERT_TRUE(ValueInStoreIs(*store(), kMergeableDictPref1, merged_dict));

  base::Value updated_dict(base::Value::Dict()
                               // New key, should get added to both
                               // stores.
                               .Set("new_key", "new_value")
                               // Updated value, should get added to both
                               // stores.
                               .Set("account_key1", "new_value1")
                               // No change, should only be in account
                               // store.
                               .Set("account_key2", "account_value2")
                               // No change, should only be in local
                               // store.
                               .Set("local_key1", "local_value1")
                               // Updated value, should get added to both
                               // stores.
                               .Set("local_key2", "new_value2")
                               // Updated value, should get added to both
                               // stores.
                               .Set("common_key1", "local_value4")
                               // Updated value, should get added to both
                               // stores.
                               .Set("common_key2", "new_common_value"));
  store()->SetValueSilently(kMergeableDictPref1, updated_dict.Clone(), 0);

  // Note: "local_key3" has been deleted.
  base::Value updated_local_dict(base::Value::Dict()
                                     .Set("new_key", "new_value")
                                     .Set("account_key1", "new_value1")
                                     .Set("local_key1", "local_value1")
                                     .Set("local_key2", "new_value2")
                                     .Set("common_key1", "local_value4")
                                     .Set("common_key2", "new_common_value"));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kMergeableDictPref1,
                             updated_local_dict));

  // Note: "account_key3" has been deleted.
  base::Value updated_account_dict(base::Value::Dict()
                                       .Set("new_key", "new_value")
                                       .Set("account_key1", "new_value1")
                                       .Set("account_key2", "account_value2")
                                       .Set("local_key2", "new_value2")
                                       .Set("common_key1", "local_value4")
                                       .Set("common_key2", "new_common_value"));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(),
                             kMergeableDictPref1, updated_account_dict));

  ASSERT_TRUE(ValueInStoreIs(*store(), kMergeableDictPref1, updated_dict));
}

TEST_F(DualLayerUserPrefStoreMergeTest,
       ShouldUnmergeAndApplyUpdatesForMergeableDictPrefOnReportPrefChanged) {

  base::Value local_dict(base::Value::Dict()
                             .Set("local_key1", "local_value1")
                             .Set("local_key2", "local_value2")
                             .Set("local_key3", "local_value3")
                             .Set("common_key1", "local_value4")
                             .Set("common_key2", "common_value"));
  store()->GetLocalPrefStore()->SetValueSilently(kMergeableDictPref1,
                                                 local_dict.Clone(), 0);

  base::Value account_dict(base::Value::Dict()
                               .Set("account_key1", "account_value1")
                               .Set("account_key2", "account_value2")
                               .Set("account_key3", "account_value3")
                               .Set("common_key1", "account_value4")
                               .Set("common_key2", "common_value"));
  store()->GetAccountPrefStore()->SetValueSilently(kMergeableDictPref1,
                                                   account_dict.Clone(), 0);

  base::Value merged_dict(base::Value::Dict()
                              .Set("account_key1", "account_value1")
                              .Set("account_key2", "account_value2")
                              .Set("account_key3", "account_value3")
                              .Set("common_key1", "account_value4")
                              .Set("common_key2", "common_value")
                              .Set("local_key1", "local_value1")
                              .Set("local_key2", "local_value2")
                              .Set("local_key3", "local_value3"));
  base::Value* merged_value = nullptr;
  ASSERT_TRUE(store()->GetMutableValue(kMergeableDictPref1, &merged_value));
  ASSERT_EQ(*merged_value, merged_dict);

  base::Value updated_dict(base::Value::Dict()
                               // New key, should get added to both
                               // stores.
                               .Set("new_key", "new_value")
                               // Updated value, should get added to both
                               // stores.
                               .Set("account_key1", "new_value1")
                               // No change, should only be in account
                               // store.
                               .Set("account_key2", "account_value2")
                               // No change, should only be in local
                               // store.
                               .Set("local_key1", "local_value1")
                               // Updated value, should get added to both
                               // stores.
                               .Set("local_key2", "new_value2")
                               // Updated value, should get added to both
                               // stores.
                               .Set("common_key1", "local_value4")
                               // Updated value, should get added to both
                               // stores.
                               .Set("common_key2", "new_common_value"));
  *merged_value = updated_dict.Clone();
  EXPECT_CALL(observer_, OnPrefValueChanged(kMergeableDictPref1));
  store()->ReportValueChanged(kMergeableDictPref1, 0);

  // Note: "local_key3" has been deleted.
  base::Value updated_local_dict(base::Value::Dict()
                                     .Set("new_key", "new_value")
                                     .Set("account_key1", "new_value1")
                                     .Set("local_key1", "local_value1")
                                     .Set("local_key2", "new_value2")
                                     .Set("common_key1", "local_value4")
                                     .Set("common_key2", "new_common_value"));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kMergeableDictPref1,
                             updated_local_dict));

  // Note: "account_key3" has been deleted.
  base::Value updated_account_dict(base::Value::Dict()
                                       .Set("new_key", "new_value")
                                       .Set("account_key1", "new_value1")
                                       .Set("account_key2", "account_value2")
                                       .Set("local_key2", "new_value2")
                                       .Set("common_key1", "local_value4")
                                       .Set("common_key2", "new_common_value"));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(),
                             kMergeableDictPref1, updated_account_dict));

  ASSERT_TRUE(ValueInStoreIs(*store(), kMergeableDictPref1, updated_dict));
}

TEST_F(DualLayerUserPrefStoreMergeTest,
       ShouldApplyUpdateOnMergeableListPrefAsNonMergeablePref) {

  base::Value local_list(
      base::Value::List().Append("local_value").Append("common_value"));
  store()->GetLocalPrefStore()->SetValueSilently(kMergeableListPref,
                                                 local_list.Clone(), 0);

  base::Value account_list(
      base::Value::List().Append("account_value").Append("common_value"));
  store()->GetAccountPrefStore()->SetValueSilently(kMergeableListPref,
                                                   account_list.Clone(), 0);

  base::Value merged_list(base::Value::List()
                              .Append("account_value")
                              .Append("common_value")
                              .Append("local_value"));
  ASSERT_TRUE(ValueInStoreIs(*store(), kMergeableListPref, merged_list));

  base::Value updated_list(base::Value::List()
                               .Append("local_value")
                               .Append("account_value")
                               .Append("common_value"));

  EXPECT_CALL(observer_, OnPrefValueChanged(kMergeableListPref));
  // Writes to both stores.
  store()->SetValue(kMergeableListPref, updated_list.Clone(), 0);

  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kMergeableListPref,
                             updated_list));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(),
                             kMergeableListPref, updated_list));

  ASSERT_TRUE(ValueInStoreIs(*store(), kMergeableListPref, updated_list));
}

TEST_F(DualLayerUserPrefStoreMergeTest,
       ShouldNotUnmergeIfIncorrectlyMarkedAsMergeableDict) {

  base::Value local_dict_value(
      base::Value::Dict().Set("local_key", "local_value"));
  store()->GetLocalPrefStore()->SetValueSilently(kMergeableDictPref1,
                                                 local_dict_value.Clone(), 0);

  base::Value account_dict_value(
      base::Value::Dict().Set("account_key", "account_value"));
  store()->GetAccountPrefStore()->SetValueSilently(
      kMergeableDictPref1, account_dict_value.Clone(), 0);

  base::Value new_value("new_value");

  EXPECT_CALL(observer_, OnPrefValueChanged(kMergeableDictPref1));
  store()->SetValue(kMergeableDictPref1, new_value.Clone(), 0);

  ASSERT_TRUE(ValueInStoreIs(*store(), kMergeableDictPref1, new_value));
  // `kMergeableDictPref1` is considered as incorrectly marked as mergeable and
  // is treated as a scalar value and overwritten to both stores.
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kMergeableDictPref1,
                             new_value));
  EXPECT_TRUE(ValueInStoreIs(*store()->GetAccountPrefStore(),
                             kMergeableDictPref1, new_value));
}

TEST_F(
    DualLayerUserPrefStoreMergeTest,
    ShouldClearAccountPrefsOnDisableAndNotifyObserversIfEffectiveValueChanges) {
  base::Value account_dict(
      base::Value::Dict().Set("common_key", "account_value"));
  store()->GetAccountPrefStore()->SetValueSilently(kMergeableDictPref1,
                                                   account_dict.Clone(), 0);
  base::Value local_dict(base::Value::Dict().Set("common_key", "local_value"));
  store()->GetLocalPrefStore()->SetValueSilently(kMergeableDictPref1,
                                                 local_dict.Clone(), 0);

  base::Value merged_dict(
      base::Value::Dict().Set("common_key", "account_value"));

  EXPECT_CALL(observer_, OnPrefValueChanged(kMergeableDictPref1));

  EXPECT_TRUE(ValueInStoreIs(*store(), kMergeableDictPref1, merged_dict));
  store()->DisableTypeAndClearAccountStore(syncer::PREFERENCES);

  // Removed from account store.
  EXPECT_TRUE(ValueInStoreIsAbsent(*store()->GetAccountPrefStore(),
                                   kMergeableDictPref1));
  // Local store is not affected.
  EXPECT_TRUE(ValueInStoreIs(*store()->GetLocalPrefStore(), kMergeableDictPref1,
                             local_dict));
  // Effective value has changed.
  EXPECT_TRUE(ValueInStoreIs(*store(), kMergeableDictPref1, local_dict));
}

TEST_F(
    DualLayerUserPrefStoreMergeTest,
    ShouldClearAccountPrefsOnDisableButNotNotifyObserversIfEffectiveValueDoesNotChange) {
  base::Value dict(base::Value::Dict().Set("common_key", "common_value"));

  store()->GetAccountPrefStore()->SetValueSilently(kMergeableDictPref1,
                                                   dict.Clone(), 0);
  store()->GetLocalPrefStore()->SetValueSilently(kMergeableDictPref1,
                                                 dict.Clone(), 0);

  EXPECT_CALL(observer_, OnPrefValueChanged(kMergeableDictPref1)).Times(0);

  EXPECT_TRUE(ValueInStoreIs(*store(), kMergeableDictPref1, dict));
  store()->DisableTypeAndClearAccountStore(syncer::PREFERENCES);
  // Removed from account store.
  EXPECT_TRUE(ValueInStoreIsAbsent(*store()->GetAccountPrefStore(),
                                   kMergeableDictPref1));
  // Local store is not affected.
  EXPECT_TRUE(
      ValueInStoreIs(*store()->GetLocalPrefStore(), kMergeableDictPref1, dict));
  // Effective value has changed as the local value is same as the previous
  // account value.
  EXPECT_TRUE(ValueInStoreIs(*store(), kMergeableDictPref1, dict));

  // `observer_` was not notified of any pref change.
}

using DualLayerUserPrefStoreHistoryOptInTest = DualLayerUserPrefStoreTest;

TEST_F(DualLayerUserPrefStoreHistoryOptInTest,
       ShouldReturnHistorySensitivePrefFromLocalStoreIfHistorySyncOff) {
  store()->SetIsHistorySyncEnabledForTest(false);

  local_store()->SetValueSilently(kHistorySensitivePrefName,
                                  base::Value("local value"), 0);
  account_store()->SetValueSilently(kHistorySensitivePrefName,
                                    base::Value("account value"), 0);

  // Check GetValue().
  EXPECT_TRUE(
      ValueInStoreIs(*store(), kHistorySensitivePrefName, "local value"));

  // Check GetMutableValue().
  {
    base::Value* value = nullptr;
    ASSERT_TRUE(store()->GetMutableValue(kHistorySensitivePrefName, &value));
    EXPECT_EQ(*value, base::Value("local value"));
  }

  // Check GetValues().
  {
    base::Value::Dict values = store()->GetValues();
    base::Value* value = values.FindByDottedPath(kHistorySensitivePrefName);
    ASSERT_TRUE(value);
    EXPECT_EQ(*value, base::Value("local value"));
  }

  // Verify that a change in history sync opt-in is reflected.
  store()->SetIsHistorySyncEnabledForTest(true);

  EXPECT_TRUE(
      ValueInStoreIs(*store(), kHistorySensitivePrefName, "account value"));
}

TEST_F(DualLayerUserPrefStoreHistoryOptInTest,
       ShouldNotGetHistorySensitivePrefFromAccountStoreIfHistorySyncOff) {
  store()->SetIsHistorySyncEnabledForTest(false);

  account_store()->SetValueSilently(kHistorySensitivePrefName,
                                    base::Value("account value"), 0);

  // Check GetValue().
  EXPECT_TRUE(ValueInStoreIsAbsent(*store(), kHistorySensitivePrefName));

  // Check GetMutableValue().
  EXPECT_FALSE(store()->GetMutableValue(kHistorySensitivePrefName, nullptr));

  // Check GetValues().
  base::Value::Dict values = store()->GetValues();
  EXPECT_FALSE(values.FindByDottedPath(kHistorySensitivePrefName));

  // Verify that a change in history sync opt-in is reflected.
  store()->SetIsHistorySyncEnabledForTest(true);

  EXPECT_TRUE(
      ValueInStoreIs(*store(), kHistorySensitivePrefName, "account value"));
}

TEST_F(DualLayerUserPrefStoreHistoryOptInTest,
       ShouldGetHistorySensitivePrefFromAccountStoreIfHistorySyncOn) {
  store()->SetIsHistorySyncEnabledForTest(true);

  local_store()->SetValueSilently(kHistorySensitivePrefName,
                                  base::Value("local value"), 0);
  account_store()->SetValueSilently(kHistorySensitivePrefName,
                                    base::Value("account value"), 0);

  // Check GetValue().
  EXPECT_TRUE(
      ValueInStoreIs(*store(), kHistorySensitivePrefName, "account value"));

  // Check GetMutableValue().
  {
    base::Value* value = nullptr;
    ASSERT_TRUE(store()->GetMutableValue(kHistorySensitivePrefName, &value));
    EXPECT_EQ(*value, base::Value("account value"));
  }

  // Check GetValues().
  {
    base::Value::Dict values = store()->GetValues();
    base::Value* value = values.FindByDottedPath(kHistorySensitivePrefName);
    ASSERT_TRUE(value);
    EXPECT_EQ(*value, base::Value("account value"));
  }
}

TEST_F(DualLayerUserPrefStoreHistoryOptInTest,
       ShouldNotSetHistorySensitivePrefInAccountStoreIfHistorySyncIsOff) {
  store()->SetIsHistorySyncEnabledForTest(false);

  testing::StrictMock<MockPrefStoreObserver> account_store_observer;
  account_store()->AddObserver(&account_store_observer);

  // No call should be made for `kHistorySensitivePrefName` since history sync
  // is off.
  EXPECT_CALL(account_store_observer,
              OnPrefValueChanged(kHistorySensitivePrefName))
      .Times(0);

  // Check SetValue().
  store()->SetValue(kHistorySensitivePrefName, base::Value("sensitive value1"),
                    0);

  EXPECT_TRUE(
      ValueInStoreIsAbsent(*account_store(), kHistorySensitivePrefName));
  ASSERT_TRUE(
      ValueInStoreIs(*store(), kHistorySensitivePrefName, "sensitive value1"));

  // Check SetValueSilently().
  store()->SetValueSilently(kHistorySensitivePrefName,
                            base::Value("sensitive value2"), 0);

  EXPECT_TRUE(
      ValueInStoreIsAbsent(*account_store(), kHistorySensitivePrefName));
  ASSERT_TRUE(
      ValueInStoreIs(*store(), kHistorySensitivePrefName, "sensitive value2"));

  // Check ReportValueChanged(). Observer is not notified.
  base::Value* value = nullptr;
  ASSERT_TRUE(store()->GetMutableValue(kHistorySensitivePrefName, &value));
  *value = base::Value("sensitive value3");
  store()->ReportValueChanged(kHistorySensitivePrefName, 0);

  EXPECT_TRUE(
      ValueInStoreIsAbsent(*account_store(), kHistorySensitivePrefName));
  ASSERT_TRUE(
      ValueInStoreIs(*store(), kHistorySensitivePrefName, "sensitive value3"));

  account_store()->RemoveObserver(&account_store_observer);
}

TEST_F(DualLayerUserPrefStoreHistoryOptInTest,
       ShouldSetHistorySensitivePrefInAccountStoreIfHistorySyncOn) {
  store()->SetIsHistorySyncEnabledForTest(true);

  testing::StrictMock<MockPrefStoreObserver> account_store_observer;
  account_store()->AddObserver(&account_store_observer);

  // Check SetValueSilently().
  store()->SetValueSilently(kHistorySensitivePrefName,
                            base::Value("sensitive value1"), 0);

  EXPECT_TRUE(ValueInStoreIs(*account_store(), kHistorySensitivePrefName,
                             "sensitive value1"));

  // Check SetValue().
  EXPECT_CALL(account_store_observer,
              OnPrefValueChanged(kHistorySensitivePrefName));
  store()->SetValue(kHistorySensitivePrefName, base::Value("sensitive value2"),
                    0);

  EXPECT_TRUE(ValueInStoreIs(*account_store(), kHistorySensitivePrefName,
                             "sensitive value2"));

  // Check ReportValueChanged().
  base::Value* value = nullptr;
  ASSERT_TRUE(store()->GetMutableValue(kHistorySensitivePrefName, &value));
  *value = base::Value("sensitive value3");

  EXPECT_CALL(account_store_observer,
              OnPrefValueChanged(kHistorySensitivePrefName));
  store()->ReportValueChanged(kHistorySensitivePrefName, 0);

  EXPECT_TRUE(ValueInStoreIs(*account_store(), kHistorySensitivePrefName,
                             "sensitive value3"));

  account_store()->RemoveObserver(&account_store_observer);
}

TEST_F(DualLayerUserPrefStoreHistoryOptInTest,
       ShouldNotRemoveFromAccountStoreUponSetIfHistorySyncOff) {
  store()->SetIsHistorySyncEnabledForTest(false);

  base::Value account_value("account value");
  account_store()->SetValueSilently(kHistorySensitivePrefName,
                                    account_value.Clone(), 0);

  testing::StrictMock<MockPrefStoreObserver> account_store_observer;
  account_store()->AddObserver(&account_store_observer);

  // No call should be made for `kHistorySensitivePrefName` since history sync
  // is off.
  EXPECT_CALL(account_store_observer,
              OnPrefValueChanged(kHistorySensitivePrefName))
      .Times(0);

  // Check SetValue().
  store()->SetValue(kHistorySensitivePrefName, base::Value("sensitive value1"),
                    0);

  EXPECT_TRUE(ValueInStoreIs(*account_store(), kHistorySensitivePrefName,
                             account_value));
  ASSERT_TRUE(
      ValueInStoreIs(*store(), kHistorySensitivePrefName, "sensitive value1"));

  // Check SetValueSilently().
  store()->SetValueSilently(kHistorySensitivePrefName,
                            base::Value("sensitive value2"), 0);

  EXPECT_TRUE(ValueInStoreIs(*account_store(), kHistorySensitivePrefName,
                             account_value));
  ASSERT_TRUE(
      ValueInStoreIs(*store(), kHistorySensitivePrefName, "sensitive value2"));

  // Check ReportValueChanged(). Observer is not notified.
  base::Value* value = nullptr;
  ASSERT_TRUE(store()->GetMutableValue(kHistorySensitivePrefName, &value));
  *value = base::Value("sensitive value3");
  store()->ReportValueChanged(kHistorySensitivePrefName, 0);

  EXPECT_TRUE(ValueInStoreIs(*account_store(), kHistorySensitivePrefName,
                             account_value));
  ASSERT_TRUE(
      ValueInStoreIs(*store(), kHistorySensitivePrefName, "sensitive value3"));

  account_store()->RemoveObserver(&account_store_observer);
}

TEST_F(DualLayerUserPrefStoreHistoryOptInTest,
       ShouldNotRemoveFromAccountStoreUponRemoveIfHistorySyncOff) {
  store()->SetIsHistorySyncEnabledForTest(false);

  base::Value local_value("local value");
  local_store()->SetValueSilently(kHistorySensitivePrefName,
                                  local_value.Clone(), 0);
  base::Value account_value("account value");
  account_store()->SetValueSilently(kHistorySensitivePrefName,
                                    account_value.Clone(), 0);

  testing::StrictMock<MockPrefStoreObserver> account_store_observer;
  account_store()->AddObserver(&account_store_observer);

  // No call should be made for `kHistorySensitivePrefName` since history sync
  // is off.
  EXPECT_CALL(account_store_observer,
              OnPrefValueChanged(kHistorySensitivePrefName))
      .Times(0);

  // Check RemoveValue().
  store()->RemoveValue(kHistorySensitivePrefName, 0);

  // Not removed from the account store.
  EXPECT_TRUE(ValueInStoreIs(*account_store(), kHistorySensitivePrefName,
                             account_value));
  // But removed from the local store.
  EXPECT_TRUE(ValueInStoreIsAbsent(*local_store(), kHistorySensitivePrefName));

  // Repopulate the local store.
  local_store()->SetValueSilently(kHistorySensitivePrefName,
                                  local_value.Clone(), 0);

  // Check RemoveValuesByPrefixSilently().
  store()->RemoveValuesByPrefixSilently(kHistorySensitivePrefName);

  // Not removed from the account store.
  EXPECT_TRUE(ValueInStoreIs(*account_store(), kHistorySensitivePrefName,
                             account_value));
  // But removed from the local store.
  EXPECT_TRUE(ValueInStoreIsAbsent(*local_store(), kHistorySensitivePrefName));

  account_store()->RemoveObserver(&account_store_observer);
}

TEST_F(DualLayerUserPrefStoreHistoryOptInTest,
       ShouldCheckHistoryOptInUponSubscribe) {
  local_store()->SetValueSilently(kHistorySensitivePrefName,
                                  base::Value("local value"), 0);
  account_store()->SetValueSilently(kHistorySensitivePrefName,
                                    base::Value("account value"), 0);

  syncer::TestSyncService sync_service;

  ASSERT_FALSE(store()->IsHistorySyncEnabledForTest());

  // OnSyncServiceInitialized() should check the history sync opt-in state.
  store()->OnSyncServiceInitialized(&sync_service);
  EXPECT_TRUE(store()->IsHistorySyncEnabledForTest());
}

TEST_F(DualLayerUserPrefStoreHistoryOptInTest,
       ShouldListenToHistorySyncDisable) {
  local_store()->SetValueSilently(kHistorySensitivePrefName,
                                  base::Value("local value"), 0);
  account_store()->SetValueSilently(kHistorySensitivePrefName,
                                    base::Value("account value"), 0);

  syncer::TestSyncService sync_service;
  store()->OnSyncServiceInitialized(&sync_service);
  ASSERT_TRUE(store()->IsHistorySyncEnabledForTest());

  testing::StrictMock<MockPrefStoreObserver> observer;
  store()->AddObserver(&observer);

  // Turning history sync off should raise notification since effective value of
  // `kHistorySensitivePrefName` pref changed.
  EXPECT_CALL(observer, OnPrefValueChanged(kHistorySensitivePrefName));
  sync_service.GetUserSettings()->SetSelectedTypes(
      /*sync_everything=*/false, syncer::UserSelectableTypeSet());
  sync_service.FireStateChanged();
  EXPECT_FALSE(store()->IsHistorySyncEnabledForTest());

  store()->RemoveObserver(&observer);
}

TEST_F(DualLayerUserPrefStoreHistoryOptInTest,
       ShouldListenToHistorySyncEnable) {
  local_store()->SetValueSilently(kHistorySensitivePrefName,
                                  base::Value("local value"), 0);
  account_store()->SetValueSilently(kHistorySensitivePrefName,
                                    base::Value("account value"), 0);

  syncer::TestSyncService sync_service;
  sync_service.GetUserSettings()->SetSelectedTypes(
      /*sync_everything=*/false, syncer::UserSelectableTypeSet());
  ASSERT_FALSE(sync_service.GetUserSettings()->GetSelectedTypes().Has(
      syncer::UserSelectableType::kHistory));

  store()->OnSyncServiceInitialized(&sync_service);
  ASSERT_FALSE(store()->IsHistorySyncEnabledForTest());

  testing::StrictMock<MockPrefStoreObserver> observer;
  store()->AddObserver(&observer);

  // Turning history sync on should raise notification since effective value of
  // `kHistorySensitivePrefName` pref changed.
  EXPECT_CALL(observer, OnPrefValueChanged(kHistorySensitivePrefName));
  sync_service.GetUserSettings()->SetSelectedTypes(
      /*sync_everything=*/false,
      syncer::UserSelectableTypeSet({syncer::UserSelectableType::kHistory}));
  sync_service.FireStateChanged();
  EXPECT_TRUE(store()->IsHistorySyncEnabledForTest());

  store()->RemoveObserver(&observer);
}

TEST_F(
    DualLayerUserPrefStoreHistoryOptInTest,
    ShouldNotNotifyObserversOnHistoryOptInChangeIfEffectiveValueDoesNotChange) {
  local_store()->SetValueSilently(kHistorySensitivePrefName,
                                  base::Value("common value"), 0);
  account_store()->SetValueSilently(kHistorySensitivePrefName,
                                    base::Value("common value"), 0);

  syncer::TestSyncService sync_service;
  sync_service.GetUserSettings()->SetSelectedTypes(
      /*sync_everything=*/false, syncer::UserSelectableTypeSet());
  ASSERT_FALSE(sync_service.GetUserSettings()->GetSelectedTypes().Has(
      syncer::UserSelectableType::kHistory));

  store()->OnSyncServiceInitialized(&sync_service);
  ASSERT_FALSE(store()->IsHistorySyncEnabledForTest());

  testing::StrictMock<MockPrefStoreObserver> observer;
  store()->AddObserver(&observer);

  // Turning history sync on should not raise notification since effective value
  // of `kHistorySensitivePrefName` pref is unchanged.
  EXPECT_CALL(observer, OnPrefValueChanged(kHistorySensitivePrefName)).Times(0);
  sync_service.GetUserSettings()->SetSelectedTypes(
      /*sync_everything=*/false,
      syncer::UserSelectableTypeSet({syncer::UserSelectableType::kHistory}));
  sync_service.FireStateChanged();
  EXPECT_TRUE(store()->IsHistorySyncEnabledForTest());

  // Turning history sync off should not raise notification since effective
  // value of `kHistorySensitivePrefName` pref is unchanged.
  EXPECT_CALL(observer, OnPrefValueChanged(kHistorySensitivePrefName)).Times(0);
  sync_service.GetUserSettings()->SetSelectedTypes(
      /*sync_everything=*/false, syncer::UserSelectableTypeSet());
  sync_service.FireStateChanged();
  EXPECT_FALSE(store()->IsHistorySyncEnabledForTest());

  store()->RemoveObserver(&observer);
}

TEST_F(DualLayerUserPrefStoreHistoryOptInTest,
       ShouldNotifyObserversOnHistoryOptInChangeIfEffectiveValueChanges) {
  account_store()->SetValueSilently(kHistorySensitivePrefName,
                                    base::Value("account value"), 0);

  syncer::TestSyncService sync_service;
  sync_service.GetUserSettings()->SetSelectedTypes(
      /*sync_everything=*/false, syncer::UserSelectableTypeSet());
  ASSERT_FALSE(sync_service.GetUserSettings()->GetSelectedTypes().Has(
      syncer::UserSelectableType::kHistory));

  store()->OnSyncServiceInitialized(&sync_service);
  ASSERT_FALSE(store()->IsHistorySyncEnabledForTest());

  testing::StrictMock<MockPrefStoreObserver> observer;
  store()->AddObserver(&observer);

  // Turning history sync on should raise notification since effective value
  // of `kHistorySensitivePrefName` pref changes.
  EXPECT_CALL(observer, OnPrefValueChanged(kHistorySensitivePrefName)).Times(1);
  sync_service.GetUserSettings()->SetSelectedTypes(
      /*sync_everything=*/false,
      syncer::UserSelectableTypeSet({syncer::UserSelectableType::kHistory}));
  sync_service.FireStateChanged();
  EXPECT_TRUE(store()->IsHistorySyncEnabledForTest());

  // Turning history sync off should raise notification since effective value
  // of `kHistorySensitivePrefName` pref changes.
  EXPECT_CALL(observer, OnPrefValueChanged(kHistorySensitivePrefName)).Times(1);
  sync_service.GetUserSettings()->SetSelectedTypes(
      /*sync_everything=*/false, syncer::UserSelectableTypeSet());
  sync_service.FireStateChanged();
  EXPECT_FALSE(store()->IsHistorySyncEnabledForTest());

  store()->RemoveObserver(&observer);
}

TEST_F(DualLayerUserPrefStoreHistoryOptInTest,
       ShouldNotReactIfHistoryOptInIsUnchanged) {
  local_store()->SetValueSilently(kHistorySensitivePrefName,
                                  base::Value("local value"), 0);
  account_store()->SetValueSilently(kHistorySensitivePrefName,
                                    base::Value("account value"), 0);

  syncer::TestSyncService sync_service;

  ASSERT_FALSE(store()->IsHistorySyncEnabledForTest());

  store()->OnSyncServiceInitialized(&sync_service);
  ASSERT_TRUE(store()->IsHistorySyncEnabledForTest());

  testing::StrictMock<MockPrefStoreObserver> observer;
  store()->AddObserver(&observer);

  // Should not lead to notification.
  sync_service.FireStateChanged();
  ASSERT_TRUE(store()->IsHistorySyncEnabledForTest());

  store()->RemoveObserver(&observer);
}

TEST_F(DualLayerUserPrefStoreHistoryOptInTest,
       ShouldRemoveSensitivePrefsFromAccountStoreUponDisableIfHistorySyncOff) {
  store()->SetIsHistorySyncEnabledForTest(false);

  base::Value account_value("account value");
  account_store()->SetValueSilently(kHistorySensitivePrefName,
                                    account_value.Clone(), 0);

  testing::StrictMock<MockPrefStoreObserver> observer;
  store()->AddObserver(&observer);

  // No call should be made for `kHistorySensitivePrefName` since history sync
  // is off and the effective is thus unchanged.
  EXPECT_CALL(observer, OnPrefValueChanged(kHistorySensitivePrefName)).Times(0);

  store()->DisableTypeAndClearAccountStore(syncer::PREFERENCES);

  EXPECT_TRUE(
      ValueInStoreIsAbsent(*account_store(), kHistorySensitivePrefName));

  store()->RemoveObserver(&observer);
}

class DualLayerUserPrefStorePriorityPrefDecoupleTest
    : public DualLayerUserPrefStoreTest {
  base::test::ScopedFeatureList scoped_feature_list_{
      syncer::kSyncSupportAlwaysSyncingPriorityPreferences};
};

TEST_F(DualLayerUserPrefStorePriorityPrefDecoupleTest,
       ShouldGetAllowlistedPrefFromAccountStoreIfUserToggleIsOff) {
  store()->SetUserSelectedTypesForTest(syncer::UserSelectableTypeSet());
  account_store()->SetValueSilently(kPriorityPrefName,
                                    base::Value("account value"), 0);
  // Allowlisted pref.
  account_store()->SetValueSilently(kAlwaysSyncingPriorityPrefName,
                                    base::Value("account value"), 0);

  // Check GetValue().
  EXPECT_TRUE(ValueInStoreIsAbsent(*store(), kPriorityPrefName));
  EXPECT_TRUE(ValueInStoreIs(*store(), kAlwaysSyncingPriorityPrefName,
                             "account value"));

  // Check GetMutableValue().
  EXPECT_FALSE(store()->GetMutableValue(kPriorityPrefName, nullptr));
  base::Value* value = nullptr;
  EXPECT_TRUE(store()->GetMutableValue(kAlwaysSyncingPriorityPrefName, &value));
  EXPECT_THAT(value, testing::Pointee(testing::Eq("account value")));

  // Check GetValues().
  base::Value::Dict values = store()->GetValues();
  EXPECT_FALSE(values.FindByDottedPath(kPriorityPrefName));
  EXPECT_THAT(values.FindByDottedPath(kAlwaysSyncingPriorityPrefName),
              testing::Pointee(testing::Eq("account value")));
}

TEST_F(DualLayerUserPrefStorePriorityPrefDecoupleTest,
       ShouldGetRegularPrefFromAccountStoreIfUserToggleIsOn) {
  store()->SetUserSelectedTypesForTest(syncer::UserSelectableTypeSet(
      {syncer::UserSelectableType::kPreferences}));
  account_store()->SetValueSilently(kPriorityPrefName,
                                    base::Value("account value"), 0);
  // Allowlisted pref.
  account_store()->SetValueSilently(kAlwaysSyncingPriorityPrefName,
                                    base::Value("account value"), 0);

  // Check GetValue().
  EXPECT_TRUE(ValueInStoreIs(*store(), kPriorityPrefName, "account value"));
  EXPECT_TRUE(ValueInStoreIs(*store(), kAlwaysSyncingPriorityPrefName,
                             "account value"));

  // Check GetMutableValue().
  base::Value* value = nullptr;
  EXPECT_TRUE(store()->GetMutableValue(kPriorityPrefName, &value));
  EXPECT_THAT(value, testing::Pointee(testing::Eq("account value")));
  EXPECT_TRUE(store()->GetMutableValue(kAlwaysSyncingPriorityPrefName, &value));
  EXPECT_THAT(value, testing::Pointee(testing::Eq("account value")));

  // Check GetValues().
  base::Value::Dict values = store()->GetValues();
  EXPECT_THAT(values.FindByDottedPath(kPriorityPrefName),
              testing::Pointee(testing::Eq("account value")));
  EXPECT_THAT(values.FindByDottedPath(kAlwaysSyncingPriorityPrefName),
              testing::Pointee(testing::Eq("account value")));
}

TEST_F(DualLayerUserPrefStorePriorityPrefDecoupleTest,
       ShouldObserverUserToggleChange) {
  syncer::TestSyncService sync_service;
  sync_service.GetUserSettings()->SetSelectedTypes(
      /*sync_everything=*/false, syncer::UserSelectableTypeSet());
  store()->OnSyncServiceInitialized(&sync_service);

  account_store()->SetValueSilently(kPriorityPrefName,
                                    base::Value("account value"), 0);
  // Allowlisted pref.
  account_store()->SetValueSilently(kAlwaysSyncingPriorityPrefName,
                                    base::Value("account value"), 0);

  EXPECT_TRUE(ValueInStoreIsAbsent(*store(), kPriorityPrefName));
  EXPECT_TRUE(ValueInStoreIs(*store(), kAlwaysSyncingPriorityPrefName,
                             "account value"));

  testing::StrictMock<MockPrefStoreObserver> observer;
  store()->AddObserver(&observer);

  EXPECT_CALL(observer, OnPrefValueChanged(kPriorityPrefName));
  EXPECT_CALL(observer, OnPrefValueChanged(kAlwaysSyncingPriorityPrefName))
      .Times(0);

  sync_service.GetUserSettings()->SetSelectedTypes(
      /*sync_everything=*/false,
      syncer::UserSelectableTypeSet(
          {syncer::UserSelectableType::kPreferences}));
  sync_service.FireStateChanged();

  EXPECT_TRUE(ValueInStoreIs(*store(), kPriorityPrefName, "account value"));
  EXPECT_TRUE(ValueInStoreIs(*store(), kAlwaysSyncingPriorityPrefName,
                             "account value"));

  store()->RemoveObserver(&observer);
}

// Test to verify that the user selected types are loaded from a pref in the
// local store.
TEST_F(DualLayerUserPrefStorePriorityPrefDecoupleTest,
       ShouldGetUserSelectedTypesFromLocalStore) {
  // Multiple types.
  local_store()->SetValueSilently(kUserSelectedTypesPrefName,
                                  base::Value(base::Value::List()
                                                  .Append("passwords")
                                                  .Append("preferences")
                                                  .Append("typedUrls")),
                                  0);
  // Only the interesting types (preferences and history) are returned.
  EXPECT_EQ(
      store()->GetUserSelectedTypesForTest(),
      syncer::UserSelectableTypeSet({syncer::UserSelectableType::kPreferences,
                                     syncer::UserSelectableType::kHistory}));

  // Empty list.
  local_store()->SetValueSilently(kUserSelectedTypesPrefName,
                                  base::Value(base::Value::List()), 0);
  EXPECT_TRUE(store()->GetUserSelectedTypesForTest().empty());
}

// Test to verify that the user selected types are stored in a pref in the local
// store.
TEST_F(DualLayerUserPrefStorePriorityPrefDecoupleTest,
       ShouldSetUserSelectedTypesToLocalStore) {
  // Multiple types.
  store()->SetUserSelectedTypesForTest(
      syncer::UserSelectableTypeSet({syncer::UserSelectableType::kPreferences,
                                     syncer::UserSelectableType::kHistory}));
  EXPECT_TRUE(ValueInStoreIs(
      *local_store(), kUserSelectedTypesPrefName,
      base::Value(
          base::Value::List().Append("preferences").Append("typedUrls"))));
  EXPECT_TRUE(
      ValueInStoreIsAbsent(*account_store(), kUserSelectedTypesPrefName));

  // Empty list.
  store()->SetUserSelectedTypesForTest(syncer::UserSelectableTypeSet());
  EXPECT_TRUE(ValueInStoreIs(*local_store(), kUserSelectedTypesPrefName,
                             base::Value(base::Value::List())));
}

// Test to verify that the user selected types pref is cleared from the local
// store upon sync stop.
TEST_F(DualLayerUserPrefStorePriorityPrefDecoupleTest,
       ShouldClearUserSelectedTypesIfLocalStoreUponSyncStop) {
  store()->SetUserSelectedTypesForTest(
      syncer::UserSelectableTypeSet({syncer::UserSelectableType::kPreferences,
                                     syncer::UserSelectableType::kHistory}));
  const base::Value user_selected_types_value(
      base::Value::List().Append("preferences").Append("typedUrls"));

  // The pref is only cleared after all the data types are disabled.
  store()->DisableTypeAndClearAccountStore(syncer::PREFERENCES);
  EXPECT_TRUE(ValueInStoreIs(*local_store(), kUserSelectedTypesPrefName,
                             user_selected_types_value));
  store()->DisableTypeAndClearAccountStore(syncer::PRIORITY_PREFERENCES);
#if BUILDFLAG(IS_CHROMEOS)
  EXPECT_TRUE(ValueInStoreIs(*local_store(), kUserSelectedTypesPrefName,
                             user_selected_types_value));
  store()->DisableTypeAndClearAccountStore(syncer::OS_PREFERENCES);
  store()->DisableTypeAndClearAccountStore(syncer::OS_PRIORITY_PREFERENCES);
#endif
  EXPECT_TRUE(ValueInStoreIs(*local_store(), kUserSelectedTypesPrefName,
                             base::Value(base::Value::List())));
}

}  // namespace
}  // namespace sync_preferences