[translate] Add translate ranker model loader.

components/translate/core/browser/translate_ranker_impl_unittest.cc

Index: components/translate/core/browser/translate_ranker_impl_unittest.cc
diff --git a/components/translate/core/browser/translate_ranker_impl_unittest.cc b/components/translate/core/browser/translate_ranker_impl_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..cb7778b4bee5edf00bb871bb4c1a14f48e6d4c9d
--- /dev/null
+++ b/components/translate/core/browser/translate_ranker_impl_unittest.cc
@@ -0,0 +1,325 @@
+// Copyright 2016 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/translate/core/browser/translate_ranker_impl.h"
+
+#include <initializer_list>
+#include <memory>
+
+#include "base/feature_list.h"
+#include "base/memory/ptr_util.h"
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
+#include "base/strings/stringprintf.h"
+#include "base/task_scheduler/post_task.h"
+#include "base/test/scoped_feature_list.h"
+#include "base/test/scoped_task_scheduler.h"
+#include "components/metrics/proto/translate_event.pb.h"
+#include "components/prefs/scoped_user_pref_update.h"
+#include "components/sync_preferences/testing_pref_service_syncable.h"
+#include "components/translate/core/browser/proto/ranker_model.pb.h"
+#include "components/translate/core/browser/proto/translate_ranker_model.pb.h"
+#include "components/translate/core/browser/ranker_model.h"
+#include "components/translate/core/browser/translate_download_manager.h"
+#include "components/translate/core/browser/translate_prefs.h"
+#include "net/url_request/test_url_fetcher_factory.h"
+#include "net/url_request/url_request_test_util.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace {
+
+using translate::kTranslateRankerEnforcement;
+using translate::kTranslateRankerLogging;
+using translate::kTranslateRankerQuery;
+using translate::TranslateDownloadManager;
+using translate::TranslateRankerFeatures;
+using translate::TranslatePrefs;
+using translate::TranslateRankerImpl;
+
+class TranslateRankerImplTest : public ::testing::Test {
+ protected:
+  TranslateRankerImplTest();
+
+  void SetUp() override;
+
+  void TearDown() override;
+
+  // Initializes the explicitly |enabled| and |disabled| features for this test.
+  void InitFeatures(const std::initializer_list<base::Feature>& enabled,
+                    const std::initializer_list<base::Feature>& disabled);
+
+  // Returns a TranslateRankerImpl object with |bias| for testing.
+  std::unique_ptr<TranslateRankerImpl> GetRankerForTest(float bias);
+
+  // Implements the same sigmoid function used by TranslateRankerImpl.
+  static double Sigmoid(double x);
+
+  // Returns a translate event initialized with the given parameters.
+  static metrics::TranslateEventProto CreateTranslateEvent(
+      const std::string& src_lang,
+      const std::string& dst_lang,
+      int accept_count,
+      int decline_count,
+      int ignore_count);
+
+  // The platform-specific name of the preferred language pref.
+  static const char* const kPreferredLanguagePref;
+
+  // Prefs.
+  std::unique_ptr<sync_preferences::TestingPrefServiceSyncable> prefs_;
+  std::unique_ptr<translate::TranslatePrefs> translate_prefs_;
+
+ private:
+  // Override the default URL fetcher to return custom responses for tests.
+  net::TestURLFetcherFactory url_fetcher_factory_;
+
+  // Used to initialize the translate download manager.
+  scoped_refptr<net::TestURLRequestContextGetter> request_context_;
+
+  // Sets up the task scheduling/task-runner environment for each test.
+  base::test::ScopedTaskScheduler scoped_task_scheduler_;
+
+  // Manages the enabling/disabling of features within the scope of a test.
+  base::test::ScopedFeatureList scoped_feature_list_;
+
+  // Cache and reset the application locale for each test.
+  std::string locale_;
+
+  DISALLOW_COPY_AND_ASSIGN(TranslateRankerImplTest);
+};
+
+const char* const TranslateRankerImplTest::kPreferredLanguagePref =
+#if defined(OS_CHROMEOS)
+    "settings.language.preferred_languages";
+#else
+    nullptr;
+#endif
+
+TranslateRankerImplTest::TranslateRankerImplTest() {}
+
+void TranslateRankerImplTest::SetUp() {
+  // Setup the translate download manager.
+  locale_ = TranslateDownloadManager::GetInstance()->application_locale();
+  request_context_ =
+      new net::TestURLRequestContextGetter(base::ThreadTaskRunnerHandle::Get());
+  TranslateDownloadManager::GetInstance()->set_application_locale("zh-CN");
+  TranslateDownloadManager::GetInstance()->set_request_context(
+      request_context_.get());
+
+  // Setup a 50/50 accepted/denied count for "english" when initialize the
+  // prefs and translate prefs.
+  base::DictionaryValue lang_count;
+  lang_count.SetInteger("en", 50);
+  prefs_.reset(new sync_preferences::TestingPrefServiceSyncable());
+  TranslatePrefs::RegisterProfilePrefs(prefs_->registry());
+  prefs_->Set(TranslatePrefs::kPrefTranslateAcceptedCount, lang_count);
+  prefs_->Set(TranslatePrefs::kPrefTranslateDeniedCount, lang_count);
+  translate_prefs_.reset(new TranslatePrefs(
+      prefs_.get(), "intl.accept_languages", kPreferredLanguagePref));
+  translate_prefs_->SetCountry("de");
+}
+
+void TranslateRankerImplTest::TearDown() {
+  base::RunLoop().RunUntilIdle();
+  TranslateDownloadManager::GetInstance()->set_application_locale(locale_);
+  TranslateDownloadManager::GetInstance()->set_request_context(nullptr);
+}
+
+void TranslateRankerImplTest::InitFeatures(
+    const std::initializer_list<base::Feature>& enabled,
+    const std::initializer_list<base::Feature>& disabled) {
+  scoped_feature_list_.InitWithFeatures(enabled, disabled);
+}
+
+std::unique_ptr<TranslateRankerImpl> TranslateRankerImplTest::GetRankerForTest(
+    float bias) {
+  auto model = base::MakeUnique<chrome_intelligence::RankerModel>();
+  auto* details = model->mutable_proto()
+                      ->mutable_translate()
+                      ->mutable_logistic_regression_model();
+  details->set_bias(bias);
+  details->set_accept_ratio_weight(0.02f);
+  details->set_decline_ratio_weight(0.03f);
+  details->set_accept_count_weight(0.13f);
+  details->set_decline_count_weight(-0.14f);
+
+  auto& src_language_weight = *details->mutable_source_language_weight();
+  src_language_weight["en"] = 0.04f;
+  src_language_weight["fr"] = 0.05f;
+  src_language_weight["zh"] = 0.06f;
+
+  auto& dest_language_weight = *details->mutable_dest_language_weight();
+  dest_language_weight["UNKNOWN"] = 0.00f;
+
+  auto& country_weight = *details->mutable_country_weight();
+  country_weight["de"] = 0.07f;
+  country_weight["ca"] = 0.08f;
+  country_weight["cn"] = 0.09f;
+
+  auto& locale_weight = *details->mutable_locale_weight();
+  locale_weight["en-us"] = 0.10f;
+  locale_weight["en-ca"] = 0.11f;
+  locale_weight["zh-cn"] = 0.12f;  // Normalized to lowercase.
+
+  auto impl = base::MakeUnique<TranslateRankerImpl>(base::FilePath(), GURL());
+  impl->OnModelAvailable(std::move(model));
+  base::RunLoop().RunUntilIdle();
+  return impl;
+}
+
+// static
+double TranslateRankerImplTest::Sigmoid(double x) {
+  return 1.0 / (1.0 + exp(-x));
+}
+
+// static
+metrics::TranslateEventProto TranslateRankerImplTest::CreateTranslateEvent(
+    const std::string& src_lang,
+    const std::string& dst_lang,
+    int accept_count,
+    int decline_count,
+    int ignore_count) {
+  metrics::TranslateEventProto translate_event;
+  translate_event.set_source_language(src_lang);
+  translate_event.set_target_language(dst_lang);
+  translate_event.set_accept_count(accept_count);
+  translate_event.set_decline_count(decline_count);
+  translate_event.set_ignore_count(ignore_count);
+  return translate_event;
+}
+
+}  // namespace
+
+TEST_F(TranslateRankerImplTest, DisabledByDefault) {
+  InitFeatures({}, {});
+  auto ranker = GetRankerForTest(0.5);
+  EXPECT_FALSE(ranker->IsQueryEnabled());
+  EXPECT_FALSE(ranker->IsEnforcementEnabled());
+  EXPECT_FALSE(ranker->IsLoggingEnabled());
+}
+
+TEST_F(TranslateRankerImplTest, ExplicitlyDisabled) {
+  InitFeatures({},
+               {kTranslateRankerQuery, kTranslateRankerEnforcement,
+                kTranslateRankerLogging});
+  auto ranker = GetRankerForTest(0.5);
+  EXPECT_FALSE(ranker->IsQueryEnabled());
+  EXPECT_FALSE(ranker->IsEnforcementEnabled());
+  EXPECT_FALSE(ranker->IsLoggingEnabled());
+}
+
+TEST_F(TranslateRankerImplTest, EnableQuery) {
+  InitFeatures({kTranslateRankerQuery}, {kTranslateRankerEnforcement});
+  auto ranker = GetRankerForTest(0.5);
+  EXPECT_TRUE(ranker->IsQueryEnabled());
+  EXPECT_FALSE(ranker->IsEnforcementEnabled());
+  EXPECT_FALSE(ranker->IsLoggingEnabled());
+}
+
+TEST_F(TranslateRankerImplTest, EnableEnforcement) {
+  InitFeatures({kTranslateRankerEnforcement}, {kTranslateRankerQuery});
+  auto ranker = GetRankerForTest(0.5);
+  EXPECT_FALSE(ranker->IsQueryEnabled());
+  EXPECT_TRUE(ranker->IsEnforcementEnabled());
+  EXPECT_FALSE(ranker->IsLoggingEnabled());
+}
+
+TEST_F(TranslateRankerImplTest, EnableQueryAndEnforcement) {
+  InitFeatures({kTranslateRankerQuery, kTranslateRankerEnforcement}, {});
+  auto ranker = GetRankerForTest(0.5);
+  EXPECT_TRUE(ranker->IsQueryEnabled());
+  EXPECT_TRUE(ranker->IsEnforcementEnabled());
+  EXPECT_FALSE(ranker->IsLoggingEnabled());
+}
+
+TEST_F(TranslateRankerImplTest, EnableLogging) {
+  InitFeatures({kTranslateRankerLogging}, {});
+  auto ranker = GetRankerForTest(0.5);
+  EXPECT_FALSE(ranker->IsQueryEnabled());
+  EXPECT_FALSE(ranker->IsEnforcementEnabled());
+  EXPECT_TRUE(ranker->IsLoggingEnabled());
+}
+
+TEST_F(TranslateRankerImplTest, EnableAll) {
+  InitFeatures({kTranslateRankerQuery, kTranslateRankerEnforcement,
+                kTranslateRankerLogging},
+               {});
+  auto ranker = GetRankerForTest(0.5);
+  EXPECT_TRUE(ranker->IsQueryEnabled());
+  EXPECT_TRUE(ranker->IsEnforcementEnabled());
+  EXPECT_TRUE(ranker->IsLoggingEnabled());
+}
+
+TEST_F(TranslateRankerImplTest, CalculateScore) {
+  InitFeatures({kTranslateRankerQuery, kTranslateRankerEnforcement}, {});
+  auto ranker = GetRankerForTest(0.01f);
+  // Calculate the score using: a 50:50 accept/decline ratio; the one-hot
+  // values for the src lang, dest lang, locale and counry; and, the bias.
+  double expected = Sigmoid(50.0 * 0.13f +   // accept count * weight
+                            50.0 * -0.14f +  // decline count * weight
+                            0.0 * 0.00f +    // ignore count * (default) weight
+                            0.5 * 0.02f +    // accept ratio * weight
+                            0.5 * 0.03f +    // decline ratio * weight
+                            0.0 * 0.00f +    // ignore ratio * (default) weight
+                            1.0 * 0.04f +  // one-hot src-language "en" * weight
+                            1.0 * 0.00f +  // one-hot dst-language "fr" * weight
+                            1.0 * 0.07f +  // one-hot country "de" * weight
+                            1.0 * 0.12f +  // one-hot locale "zh-CN" * weight
+                            0.01f);        // bias
+  TranslateRankerFeatures features(50, 50, 0, "en", "fr", "de", "zh-CN");
+
+  EXPECT_NEAR(expected, ranker->CalculateScore(features), 0.000001);
+}
+
+TEST_F(TranslateRankerImplTest, ShouldOfferTranslation) {
+  InitFeatures({kTranslateRankerQuery, kTranslateRankerEnforcement}, {});
+  // With a bias of -0.5 en->fr is not over the threshold.
+  EXPECT_FALSE(GetRankerForTest(-0.5f)->ShouldOfferTranslation(
+      *translate_prefs_, "en", "fr"));
+  // With a bias of 0.25 en-fr is over the threshold.
+  EXPECT_TRUE(GetRankerForTest(0.25f)->ShouldOfferTranslation(*translate_prefs_,
+                                                              "en", "fr"));
+}
+
+TEST_F(TranslateRankerImplTest, RecordAndFlushEvents) {
+  InitFeatures({kTranslateRankerLogging}, {});
+  std::unique_ptr<translate::TranslateRanker> ranker = GetRankerForTest(0.0f);
+  std::vector<metrics::TranslateEventProto> flushed_events;
+
+  // Check that flushing an empty cache will return an empty vector.
+  ranker->FlushTranslateEvents(&flushed_events);
+  EXPECT_EQ(0U, flushed_events.size());
+
+  ranker->AddTranslateEvent(CreateTranslateEvent("fr", "en", 1, 0, 3));
+  ranker->AddTranslateEvent(CreateTranslateEvent("jp", "en", 2, 0, 3));
+  ranker->AddTranslateEvent(CreateTranslateEvent("es", "de", 4, 5, 6));
+
+  // Capture the data and verify that it is as expected.
+  ranker->FlushTranslateEvents(&flushed_events);
+  EXPECT_EQ(3U, flushed_events.size());
+  ASSERT_EQ("fr", flushed_events[0].source_language());
+  ASSERT_EQ("jp", flushed_events[1].source_language());
+  ASSERT_EQ("es", flushed_events[2].source_language());
+
+  // Check that the cache has been cleared.
+  ranker->FlushTranslateEvents(&flushed_events);
+  EXPECT_EQ(0U, flushed_events.size());
+}
+
+TEST_F(TranslateRankerImplTest, LoggingDisabled) {
+  InitFeatures({}, {kTranslateRankerLogging});
+  std::unique_ptr<translate::TranslateRanker> ranker = GetRankerForTest(0.0f);
+  std::vector<metrics::TranslateEventProto> flushed_events;
+
+  ranker->FlushTranslateEvents(&flushed_events);
+  EXPECT_EQ(0U, flushed_events.size());
+
+  ranker->AddTranslateEvent(CreateTranslateEvent("fr", "en", 1, 0, 3));
+  ranker->AddTranslateEvent(CreateTranslateEvent("jp", "en", 2, 0, 3));
+  ranker->AddTranslateEvent(CreateTranslateEvent("es", "de", 4, 5, 6));
+
+  // Logging is disabled, so no events should be cached.
+  ranker->FlushTranslateEvents(&flushed_events);
+  EXPECT_EQ(0U, flushed_events.size());
+}