text: // Copyright (c) 2011 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 "chrome/renderer/safe_browsing/scorer.h"
  
  #include <stdint.h>
  
  #include "base/containers/hash_tables.h"
  #include "base/files/file_path.h"
  #include "base/files/scoped_temp_dir.h"
  #include "base/format_macros.h"
  #include "base/memory/scoped_ptr.h"
  #include "base/message_loop/message_loop.h"
  #include "base/threading/thread.h"
  #include "chrome/common/safe_browsing/client_model.pb.h"
  #include "chrome/renderer/safe_browsing/features.h"
  #include "testing/gmock/include/gmock/gmock.h"
  #include "testing/gtest/include/gtest/gtest.h"
  
  namespace safe_browsing {
  
  class PhishingScorerTest : public ::testing::Test {
   protected:
    void SetUp() override {
      // Setup a simple model.  Note that the scorer does not care about
      // how features are encoded so we use readable strings here to make
      // the test simpler to follow.
      model_.Clear();
      model_.add_hashes("feature1");
      model_.add_hashes("feature2");
      model_.add_hashes("feature3");
      model_.add_hashes("token one");
      model_.add_hashes("token two");
  
      ClientSideModel::Rule* rule;
      rule = model_.add_rule();
      rule->set_weight(0.5);
  
      rule = model_.add_rule();
      rule->add_feature(0);  // feature1
      rule->set_weight(2.0);
  
      rule = model_.add_rule();
      rule->add_feature(0);  // feature1
      rule->add_feature(1);  // feature2
      rule->set_weight(3.0);
  
      model_.add_page_term(3);  // token one
      model_.add_page_term(4);  // token two
  
      // These will be murmur3 hashes, but for this test it's not necessary
      // that the hashes correspond to actual words.
      model_.add_page_word(1000U);
      model_.add_page_word(2000U);
      model_.add_page_word(3000U);
  
      model_.set_max_words_per_term(2);
      model_.set_murmur_hash_seed(12345U);
      model_.set_max_shingles_per_page(10);
      model_.set_shingle_size(3);
    }
  
    ClientSideModel model_;
  };
  
  TEST_F(PhishingScorerTest, HasValidModel) {
    scoped_ptr<Scorer> scorer;
    scorer.reset(Scorer::Create(model_.SerializeAsString()));
    EXPECT_TRUE(scorer.get() != NULL);
  
    // Invalid model string.
    scorer.reset(Scorer::Create("bogus string"));
    EXPECT_FALSE(scorer.get());
  
    // Mode is missing a required field.
    model_.clear_max_words_per_term();
    scorer.reset(Scorer::Create(model_.SerializePartialAsString()));
    EXPECT_FALSE(scorer.get());
  }
  
  TEST_F(PhishingScorerTest, PageTerms) {
    scoped_ptr<Scorer> scorer(Scorer::Create(model_.SerializeAsString()));
    ASSERT_TRUE(scorer.get());
  
    // Use std::vector instead of base::hash_set for comparison.
    // On Android, EXPECT_THAT(..., ContainerEq(...)) doesn't support
    // std::hash_set, but std::vector works fine.
    std::vector<std::string> expected_page_terms;
    expected_page_terms.push_back("token one");
    expected_page_terms.push_back("token two");
    std::sort(expected_page_terms.begin(), expected_page_terms.end());
  
    base::hash_set<std::string> page_terms = scorer->page_terms();
    std::vector<std::string> page_terms_v(page_terms.begin(), page_terms.end());
    std::sort(page_terms_v.begin(), page_terms_v.end());
  
    EXPECT_THAT(page_terms_v, ::testing::ContainerEq(expected_page_terms));
  }
  
  TEST_F(PhishingScorerTest, PageWords) {
    scoped_ptr<Scorer> scorer(Scorer::Create(model_.SerializeAsString()));
    ASSERT_TRUE(scorer.get());
    std::vector<uint32_t> expected_page_words;
    expected_page_words.push_back(1000U);
    expected_page_words.push_back(2000U);
    expected_page_words.push_back(3000U);
    std::sort(expected_page_words.begin(), expected_page_words.end());
  
    base::hash_set<uint32_t> page_words = scorer->page_words();
    std::vector<uint32_t> page_words_v(page_words.begin(), page_words.end());
    std::sort(page_words_v.begin(), page_words_v.end());
  
    EXPECT_THAT(page_words_v, ::testing::ContainerEq(expected_page_words));
  
    EXPECT_EQ(2U, scorer->max_words_per_term());
    EXPECT_EQ(12345U, scorer->murmurhash3_seed());
    EXPECT_EQ(10U, scorer->max_shingles_per_page());
    EXPECT_EQ(3U, scorer->shingle_size());
  }
  
  TEST_F(PhishingScorerTest, ComputeScore) {
    scoped_ptr<Scorer> scorer(Scorer::Create(model_.SerializeAsString()));
    ASSERT_TRUE(scorer.get());
  
    // An empty feature map should match the empty rule.
    FeatureMap features;
    // The expected logodds is 0.5 (empty rule) => p = exp(0.5) / (exp(0.5) + 1)
    // => 0.62245933120185459
    EXPECT_DOUBLE_EQ(0.62245933120185459, scorer->ComputeScore(features));
    // Same if the feature does not match any rule.
    EXPECT_TRUE(features.AddBooleanFeature("not existing feature"));
    EXPECT_DOUBLE_EQ(0.62245933120185459, scorer->ComputeScore(features));
  
    // Feature 1 matches which means that the logodds will be:
    //   0.5 (empty rule) + 2.0 (rule weight) * 0.15 (feature weight) = 0.8
    //   => p = 0.6899744811276125
    EXPECT_TRUE(features.AddRealFeature("feature1", 0.15));
    EXPECT_DOUBLE_EQ(0.6899744811276125, scorer->ComputeScore(features));
  
    // Now, both feature 1 and feature 2 match.  Expected logodds:
    //   0.5 (empty rule) + 2.0 (rule weight) * 0.15 (feature weight) +
    //   3.0 (rule weight) * 0.15 (feature1 weight) * 1.0 (feature2) weight = 9.8
    //   => p = 0.99999627336071584
    EXPECT_TRUE(features.AddBooleanFeature("feature2"));
    EXPECT_DOUBLE_EQ(0.77729986117469119, scorer->ComputeScore(features));
  }
  }  // namespace safe_browsing
  