[NTP Snippets] Persist snippets in a LevelDB instead of prefs

components/ntp_snippets/ntp_snippets_service_unittest.cc

 // Copyright 2015 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 "components/ntp_snippets/ntp_snippets_service.h"
 
 #include <memory>
 #include <vector>
 
 #include "base/command_line.h"
+#include "base/files/file_path.h"
+#include "base/files/scoped_temp_dir.h"
 #include "base/json/json_reader.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/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/test/histogram_tester.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "components/image_fetcher/image_fetcher.h"
 #include "components/ntp_snippets/ntp_snippet.h"
+#include "components/ntp_snippets/ntp_snippets_database.h"
 #include "components/ntp_snippets/ntp_snippets_fetcher.h"
 #include "components/ntp_snippets/ntp_snippets_scheduler.h"
 #include "components/ntp_snippets/switches.h"
 #include "components/prefs/testing_pref_service.h"
 #include "components/signin/core/browser/account_tracker_service.h"
 #include "components/signin/core/browser/fake_profile_oauth2_token_service.h"
 #include "components/signin/core/browser/fake_signin_manager.h"
 #include "components/signin/core/browser/test_signin_client.h"
 #include "components/sync_driver/fake_sync_service.h"
 #include "google_apis/google_api_keys.h"
@@ skipping 195 matching lines @@
   MOCK_CONST_METHOD0(GetActiveDataTypes, syncer::ModelTypeSet());
 };
 
 class MockServiceObserver : public NTPSnippetsServiceObserver {
  public:
   MOCK_METHOD0(NTPSnippetsServiceLoaded, void());
   MOCK_METHOD0(NTPSnippetsServiceShutdown, void());
   MOCK_METHOD0(NTPSnippetsServiceDisabled, void());
 };
 
+class WaitForDBLoad : public NTPSnippetsServiceObserver {
+ public:
+  WaitForDBLoad(NTPSnippetsService* service) : service_(service) {
+    EXPECT_TRUE(!service_->loaded());
+    service_->AddObserver(this);
+    run_loop_.Run();

[Bernhard Bauer, 2016/05/25 15:01:15]

If you already have an object for this, you could move the Run() to a separate
method, so you can create this first, then call Init() on the service, then wait
for it to finish. That way it will also work if the service finishes loading
synchronously.

[Marc Treib, 2016/05/27 14:03:12]

Init() doesn't exist anymore :)
I guess we could return early if the service is already loaded, but since that
can't happen right now, I'd prefer to keep this as-is.

[Bernhard Bauer, 2016/05/27 16:06:43]

It's a bit of a defense-in-depth thing: if you at some point in the future
should notify synchronously, you might start failing in this test. The test code
is a common pattern: First set up the observer, then do the action, then wait
for the observation.

[Marc Treib, 2016/05/30 13:22:00]

This pattern isn't possible anymore, since the NTPSnippetsService ctor
immediately starts the DB load.
I have changed the helper to also handle the case when the DB is already loaded,
so it'll continue to work if that ever becomes synchronous.

+  }
+
+  ~WaitForDBLoad() override {
+    service_->RemoveObserver(this);
+  }
+
+ private:
+  void NTPSnippetsServiceLoaded() override {
+    EXPECT_TRUE(service_->loaded());
+    run_loop_.Quit();
+  }
+
+  void NTPSnippetsServiceShutdown() override {};

[Bernhard Bauer, 2016/05/25 15:01:15]

No semicolon

[Marc Treib, 2016/05/27 14:03:13]

Done.

+  void NTPSnippetsServiceDisabled() override {};
+
+  NTPSnippetsService* service_;
+  base::RunLoop run_loop_;
+
+  DISALLOW_COPY_AND_ASSIGN(WaitForDBLoad);
+};
+
 }  // namespace
 
 class NTPSnippetsServiceTest : public testing::Test {
  public:
   NTPSnippetsServiceTest()
       : fake_url_fetcher_factory_(
             /*default_factory=*/&failing_url_fetcher_factory_),
         test_url_(base::StringPrintf(kTestContentSnippetsServerFormat,
                                      google_apis::GetAPIKey().c_str())),
         pref_service_(new TestingPrefServiceSimple()),
         signin_client_(new TestSigninClient(nullptr)),
         account_tracker_(new AccountTrackerService()),
         fake_signin_manager_(new FakeSigninManagerBase(signin_client_.get(),
                                                        account_tracker_.get())),
         fake_token_service_(new FakeProfileOAuth2TokenService()) {
     NTPSnippetsService::RegisterProfilePrefs(pref_service_->registry());
     // Since no SuggestionsService is injected in tests, we need to force the
     // service to fetch from all hosts.
     base::CommandLine::ForCurrentProcess()->AppendSwitch(
         switches::kDontRestrict);
+    EXPECT_TRUE(database_dir_.CreateUniqueTempDir());
   }
 
   ~NTPSnippetsServiceTest() override {
     if (service_)
       service_->Shutdown();
   }
 
   void SetUp() override {
     EXPECT_CALL(mock_scheduler(), Schedule(_, _, _, _)).Times(1);
     CreateSnippetsService(/*enabled=*/true);
   }
 
   void CreateSnippetsService(bool enabled) {
     if (service_)
       service_->Shutdown();
 
     scoped_refptr<base::SingleThreadTaskRunner> task_runner(
         base::ThreadTaskRunnerHandle::Get());
     scoped_refptr<net::TestURLRequestContextGetter> request_context_getter =
         new net::TestURLRequestContextGetter(task_runner.get());
 
+    // Delete the current service, so that the database is destroyed before we
+    // create the new one, otherwise opening the new database will fail.
+    service_.reset();
+
     service_.reset(new NTPSnippetsService(
-        pref_service_.get(), mock_sync_service_.get(), nullptr, task_runner,
+        pref_service_.get(), mock_sync_service_.get(), nullptr,
         std::string("fr"), &scheduler_,
         base::WrapUnique(new NTPSnippetsFetcher(
             fake_signin_manager_.get(), fake_token_service_.get(),
             std::move(request_context_getter), base::Bind(&ParseJson),
             /*is_stable_channel=*/true)),
-        /*image_fetcher=*/nullptr));
+        /*image_fetcher=*/nullptr,
+        base::WrapUnique(new NTPSnippetsDatabase(database_dir_.path(),
+                                                 task_runner))));
     service_->Init(enabled);
+    if (enabled)
+      WaitForDBLoad(service_.get());
   }
 
  protected:
   const GURL& test_url() { return test_url_; }
   NTPSnippetsService* service() { return service_.get(); }
   MockScheduler& mock_scheduler() {  return scheduler_; }
   MockSyncService* mock_sync_service() { return mock_sync_service_.get(); }
 
   // Provide the json to be returned by the fake fetcher.
   void SetUpFetchResponse(const std::string& json) {
@@ skipping 33 matching lines @@
   std::unique_ptr<TestingPrefServiceSimple> pref_service_;
   std::unique_ptr<TestSigninClient> signin_client_;
   std::unique_ptr<AccountTrackerService> account_tracker_;
   std::unique_ptr<MockSyncService> mock_sync_service_;  // Null by default.
   std::unique_ptr<SigninManagerBase> fake_signin_manager_;
   std::unique_ptr<OAuth2TokenService> fake_token_service_;
   MockScheduler scheduler_;
   // Last so that the dependencies are deleted after the service.
   std::unique_ptr<NTPSnippetsService> service_;
 
+  base::ScopedTempDir database_dir_;
+
   DISALLOW_COPY_AND_ASSIGN(NTPSnippetsServiceTest);
 };
 
 class NTPSnippetsServiceWithSyncTest : public NTPSnippetsServiceTest {
  public:
   void SetUp() override {
     ResetSyncServiceMock();
     NTPSnippetsServiceTest::SetUp();
   }
 };
@@ skipping 530 matching lines @@
   // The service should be ready again and load snippets.
   SetUpFetchResponse(GetTestJson({GetSnippet()}));
   service()->OnStateChanged();
   base::RunLoop().RunUntilIdle();
   EXPECT_FALSE(service()->snippets().empty());
 
   service()->RemoveObserver(&mock_observer);
 }
 
 }  // namespace ntp_snippets