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_; }

[Sam McNally, 2017/02/24 04:14:54]

How about returning a PrefStoreObserverMock&?

[tibell, 2017/02/27 00:02:54]

VerifyAndClearExpectations needs a pointer.

+  PrefStoreClient* store() { return store_.get(); }
+
+  bool Initialized() { return store_->initialized_; }

[Sam McNally, 2017/02/24 04:14:53]

initialized()

[tibell, 2017/02/27 00:02:54]

Done.

+  void OnPreferencesChanged(const base::DictionaryValue& preferences) {
+    observer_ptr_->OnPreferencesChanged(preferences.CreateDeepCopy());
+  }
+  void OnInitializationCompleted() {
+    observer_ptr_->OnInitializationCompleted(true);
+  }
+
+  // testing::Test:
+  void SetUp() override;
+  void TearDown() override;
+
+ 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);
+};
+
+void PrefStoreClientTest::SetUp() {
+  mojom::PrefStoreConnectionPtr connection_ptr =

[Sam McNally, 2017/02/24 04:14:54]

connection

[tibell, 2017/02/27 00:02:54]

I like this naming pattern for InterfacePtrs.

+      mojom::PrefStoreConnection::New();
+  connection_ptr->observer = mojo::MakeRequest(&observer_ptr_);
+  connection_ptr->initial_prefs = base::MakeUnique<base::DictionaryValue>();
+  connection_ptr->is_initialized = false;
+  store_ = new PrefStoreClient(std::move(connection_ptr));
+  store_->AddObserver(&observer_);
+}
+
+void PrefStoreClientTest::TearDown() {
+  store_->RemoveObserver(&observer_);
+}

[Sam McNally, 2017/02/24 04:14:53]

store_.reset();

[tibell, 2017/02/27 00:02:54]

Done.

+
+// 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 std::string key("hey");

[Sam McNally, 2017/02/24 04:14:53]

Can't use const char []?

[tibell, 2017/02/27 00:02:54]

Done.

+  const int kValue = 42;
+  base::FundamentalValue pref(kValue);
+  base::DictionaryValue prefs;
+  prefs.Set(key, pref.CreateDeepCopy());
+
+  // 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();
+  OnPreferencesChanged(prefs);
+  loop.Run();
+  EXPECT_TRUE(Initialized());
+
+  const base::Value* value = nullptr;
+  int actual_value;
+  EXPECT_TRUE(store()->GetValue(key, &value));

[Sam McNally, 2017/02/24 04:14:54]

ASSERT_TRUE

[tibell, 2017/02/27 00:02:54]

Not needed since the next test won't crash even if we don't.

+  EXPECT_NE(nullptr, value);

[Sam McNally, 2017/02/24 04:14:54]

ASSERT_TRUE(value)

[tibell, 2017/02/27 00:02:54]

Done.

+  EXPECT_TRUE(value->GetAsInteger(&actual_value));

[Sam McNally, 2017/02/24 04:14:53]

ASSERT_TRUE

[tibell, 2017/02/27 00:02:54]

If we get here this comparison can't crash.

+  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 std::string key1("hey");
+  const std::string key2("listen");
+
+  EXPECT_FALSE(Initialized());
+  EXPECT_CALL(*observer(), OnInitializationCompleted(_)).Times(0);
+
+  testing::Mock::VerifyAndClearExpectations(observer());
+
+  const int kValue = 42;
+  base::FundamentalValue pref1(kValue);
+  const std::string kStringValue("look");
+  base::StringValue pref2(kStringValue);
+
+  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();
+  OnPreferencesChanged(prefs);
+  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 std::string key("hey");
+  const int kValue = 42;
+  base::FundamentalValue pref(kValue);
+  base::DictionaryValue prefs;
+  prefs.Set(key, pref.CreateDeepCopy());
+
+  // 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();
+  OnPreferencesChanged(prefs);
+  loop.Run();
+
+  store()->RemoveObserver(&observer2);
+}
+
+}  // namespace prefs