Pref service: expose all read-only PrefStores through Mojo

services/preferences/public/cpp/tests/pref_store_client_unittest.cc

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "services/preferences/public/cpp/pref_store_client.h"
+
+#include "base/macros.h"
+#include "base/memory/ptr_util.h"
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
+#include "base/values.h"
+#include "services/preferences/public/interfaces/preferences.mojom.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using testing::Invoke;
+using testing::WithArg;
+using testing::WithoutArgs;
+using testing::_;
+
+namespace prefs {
+
+namespace {
+
+class PrefStoreObserverMock : public PrefStore::Observer {
+ public:
+  MOCK_METHOD1(OnPrefValueChanged, void(const std::string&));
+  MOCK_METHOD1(OnInitializationCompleted, void(bool succeeded));
+};
+
+class PrefStoreConnectorMock : public mojom::PrefStoreConnector {
+ public:
+  MOCK_METHOD1(Connect, void(const ConnectCallback&));
+};
+
+}  // namespace
+
+class PrefStoreClientTest : public testing::Test {
+ public:
+  PrefStoreClientTest() = default;
+  ~PrefStoreClientTest() override {}
+
+  PrefStoreObserverMock& observer() { return observer_; }
+  PrefStoreClient* store() { return store_.get(); }
+
+  bool initialized() { return store_->initialized_; }
+  void OnPrefChanged(const std::string& key, const base::Value& value) {
+    observer_ptr_->OnPrefChanged(key, value.CreateDeepCopy());
+  }
+  void OnInitializationCompleted() {
+    observer_ptr_->OnInitializationCompleted(true);
+  }
+
+  // testing::Test:
+  void SetUp() override {
+    store_ = new PrefStoreClient(mojom::PrefStoreConnection::New(
+        mojo::MakeRequest(&observer_ptr_),
+        base::MakeUnique<base::DictionaryValue>(), false));
+    store_->AddObserver(&observer_);
+  }
+  void TearDown() override {
+    store_->RemoveObserver(&observer_);
+    store_ = nullptr;
+  }
+
+ private:
+  mojom::PrefStoreObserverPtr observer_ptr_;
+  PrefStoreObserverMock observer_;
+  scoped_refptr<PrefStoreClient> store_;
+
+  // Required by mojo binding code within PrefStoreClient.
+  base::MessageLoop message_loop_;
+
+  DISALLOW_COPY_AND_ASSIGN(PrefStoreClientTest);
+};
+
+// Tests that observers are notified upon the completion of initialization, and
+// that values become available.
+TEST_F(PrefStoreClientTest, Initialization) {
+  // The store should start out uninitialized if the backing store does.
+  EXPECT_FALSE(initialized());
+  EXPECT_CALL(observer(), OnInitializationCompleted(_)).Times(0);
+
+  testing::Mock::VerifyAndClearExpectations(&observer());
+
+  const char key[] = "hey";
+  const int kValue = 42;
+  base::Value pref(kValue);
+
+  // PrefStore notifies of PreferencesChanged, completing
+  // initialization.
+  base::RunLoop loop;
+  EXPECT_CALL(observer(), OnInitializationCompleted(true));
+  EXPECT_CALL(observer(), OnPrefValueChanged(key))
+      .WillOnce(WithoutArgs(Invoke([&loop]() { loop.Quit(); })));
+  OnInitializationCompleted();
+  OnPrefChanged(key, pref);
+  loop.Run();
+  EXPECT_TRUE(initialized());
+
+  const base::Value* value = nullptr;
+  int actual_value;
+  EXPECT_TRUE(store()->GetValue(key, &value));
+  ASSERT_TRUE(value);
+  EXPECT_TRUE(value->GetAsInteger(&actual_value));
+  EXPECT_EQ(kValue, actual_value);
+}
+
+// Test that when initialized with multiple keys, that observers receive a
+// notification for each key.
+TEST_F(PrefStoreClientTest, MultipleKeyInitialization) {
+  const char key1[] = "hey";
+  const char key2[] = "listen";
+
+  EXPECT_FALSE(initialized());
+  EXPECT_CALL(observer(), OnInitializationCompleted(_)).Times(0);
+
+  testing::Mock::VerifyAndClearExpectations(&observer());
+
+  const int kValue = 42;
+  base::Value pref1(kValue);
+  base::Value pref2("look");
+
+  base::DictionaryValue prefs;
+  prefs.Set(key1, pref1.CreateDeepCopy());
+  prefs.Set(key2, pref2.CreateDeepCopy());
+
+  // The observer should be notified of all keys set.
+  base::RunLoop loop;
+  EXPECT_CALL(observer(), OnInitializationCompleted(true));
+  EXPECT_CALL(observer(), OnPrefValueChanged(key1));
+  EXPECT_CALL(observer(), OnPrefValueChanged(key2))
+      .WillOnce(WithoutArgs(Invoke([&loop]() { loop.Quit(); })));
+  OnInitializationCompleted();
+  OnPrefChanged(key1, pref1);
+  OnPrefChanged(key2, pref2);
+  loop.Run();
+  EXPECT_TRUE(initialized());
+}
+
+// Tests that multiple PrefStore::Observers can be added to a PrefStoreClient
+// and that they are each notified of changes.
+TEST_F(PrefStoreClientTest, MultipleObservers) {
+  PrefStoreObserverMock observer2;
+  store()->AddObserver(&observer2);
+
+  const char key[] = "hey";
+  const int kValue = 42;
+  base::Value pref(kValue);
+
+  // PrefStore notifies of PreferencesChanged, completing
+  // initialization.
+  base::RunLoop loop;
+  EXPECT_CALL(observer(), OnInitializationCompleted(true));
+  EXPECT_CALL(observer2, OnInitializationCompleted(true));
+  EXPECT_CALL(observer(), OnPrefValueChanged(key));
+  EXPECT_CALL(observer2, OnPrefValueChanged(key))
+      .WillOnce(WithoutArgs(Invoke([&loop]() { loop.Quit(); })));
+  OnInitializationCompleted();
+  OnPrefChanged(key, pref);
+  loop.Run();
+
+  store()->RemoveObserver(&observer2);
+}
+
+TEST_F(PrefStoreClientTest, Initialized) {
+  mojom::PrefStoreObserverPtr observer_ptr;
+  PrefStoreObserverMock observer;
+  const char key[] = "hey";
+  const int kValue = 42;
+  base::Value pref(kValue);
+  auto prefs = base::MakeUnique<base::DictionaryValue>();
+  prefs->Set(key, pref.CreateDeepCopy());
+  auto store =
+      make_scoped_refptr(new PrefStoreClient(mojom::PrefStoreConnection::New(
+          mojo::MakeRequest(&observer_ptr), std::move(prefs), true)));
+  store->AddObserver(&observer);
+
+  const base::Value* value = nullptr;
+  int actual_value = 0;
+  EXPECT_TRUE(store->GetValue(key, &value));
+  ASSERT_TRUE(value);
+  EXPECT_TRUE(value->GetAsInteger(&actual_value));
+  EXPECT_EQ(kValue, actual_value);
+  EXPECT_CALL(observer, OnInitializationCompleted(_)).Times(0);
+  EXPECT_CALL(observer, OnPrefValueChanged(_)).Times(0);
+  observer_ptr.FlushForTesting();
+
+  store->RemoveObserver(&observer);
+}
+
+}  // namespace prefs