app_list search results relevance scores are clamped to [0, 1] range.

ui/app_list/search/mixer_unittest.cc

Index: ui/app_list/search/mixer_unittest.cc
diff --git a/ui/app_list/search/mixer_unittest.cc b/ui/app_list/search/mixer_unittest.cc
index 565b81bdf1e965b843b3a4211e609958b64e249b..78c233eec1ef9f367dff3062959064e9fd94dcee 100644
--- a/ui/app_list/search/mixer_unittest.cc
+++ b/ui/app_list/search/mixer_unittest.cc
@@ -57,7 +57,7 @@ int TestSearchResult::instantiation_count = 0;
 class TestSearchProvider : public SearchProvider {
  public:
   explicit TestSearchProvider(const std::string& prefix)
-      : prefix_(prefix), count_(0) {}
+      : prefix_(prefix), count_(0), bad_relevance_range_(false) {}
   ~TestSearchProvider() override {}
 
   // SearchProvider overrides:
@@ -66,7 +66,11 @@ class TestSearchProvider : public SearchProvider {
     for (size_t i = 0; i < count_; ++i) {
       const std::string id =
           base::StringPrintf("%s%d", prefix_.c_str(), static_cast<int>(i));
-      const double relevance = 1.0 - i / 10.0;
+      double relevance = 1.0 - i / 10.0;
+      // If bad_relevance_range_, change the relevances to give results outside
+      // of the canonical [0.0, 1.0] range.
+      if (bad_relevance_range_)
+        relevance = 10.0 - i * 10;
       TestSearchResult* result = new TestSearchResult(id, relevance);
       if (voice_result_indices.find(i) != voice_result_indices.end())
         result->set_voice_result(true);
@@ -78,10 +82,12 @@ class TestSearchProvider : public SearchProvider {
   void set_prefix(const std::string& prefix) { prefix_ = prefix; }
   void set_count(size_t count) { count_ = count; }
   void set_as_voice_result(size_t index) { voice_result_indices.insert(index); }
+  void set_bad_relevance_range() { bad_relevance_range_ = true; }
 
  private:
   std::string prefix_;
   size_t count_;
+  bool bad_relevance_range_;
   // Indices of results that will have the |voice_result| flag set.
   std::set<size_t> voice_result_indices;
 
@@ -264,6 +270,25 @@ TEST_F(MixerTest, VoiceQuery) {
   EXPECT_EQ("omnibox1,omnibox2,omnibox0", GetResults());
 }
 
+TEST_F(MixerTest, BadRelevanceRange) {
+  // This gives relevance scores: (10.0, 0.0). Even though providers are
+  // supposed to give scores within the range [0.0, 1.0], we cannot rely on
+  // providers to do this, since they retrieve results from disparate and
+  // unreliable sources (like the Google+ API).
+  people_provider()->set_bad_relevance_range();
+  people_provider()->set_count(2);
+
+  // Give a massive boost to the second result.
+  AddKnownResult("people1", PERFECT_PRIMARY);
+
+  RunQuery();
+
+  // If the results are correctly clamped to the range [0.0, 1.0], the boost to
+  // "people1" will push it over the first result. If not, the massive base
+  // score of "people0" will erroneously keep it on top.
+  EXPECT_EQ("people1,people0", GetResults());
+}
+
 TEST_F(MixerTest, Publish) {
   scoped_ptr<SearchResult> result1(new TestSearchResult("app1", 0));
   scoped_ptr<SearchResult> result2(new TestSearchResult("app2", 0));