Allow trials to associate without overriding a feature.

components/variations/variations_seed_processor_unittest.cc

 // Copyright 2013 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/variations/variations_seed_processor.h"
 
 #include <stddef.h>
 #include <stdint.h>
 #include <map>
 #include <utility>
@@ skipping 341 matching lines @@
   EXPECT_FALSE(processed_study.Init(&study, false));
 
   default_group->set_name("def");
   EXPECT_TRUE(processed_study.Init(&study, false));
   Study_Experiment* repeated_group = study.add_experiment();
   repeated_group->set_name("abc");
   repeated_group->set_probability_weight(1);
   EXPECT_FALSE(processed_study.Init(&study, false));
 }
 
+TEST_F(VariationsSeedProcessorTest, ValidateStudySingleFeature) {
+  Study study;
+  study.set_default_experiment_name("def");
+  Study_Experiment* exp1 = AddExperiment("exp1", 100, &study);
+  Study_Experiment* exp2 = AddExperiment("exp2", 100, &study);
+  Study_Experiment* exp3 = AddExperiment("exp3", 100, &study);
+  AddExperiment("def", 100, &study);
+
+  ProcessedStudy processed_study;
+  EXPECT_TRUE(processed_study.Init(&study, false));
+  EXPECT_EQ(400, processed_study.total_probability());
+
+  EXPECT_EQ(std::string(), processed_study.single_feature_name());
+
+  const char kFeature1Name[] = "Feature1";
+  const char kFeature2Name[] = "Feature2";
+
+  exp1->mutable_feature_association()->add_enable_feature(kFeature1Name);
+  EXPECT_TRUE(processed_study.Init(&study, false));
+  EXPECT_EQ(kFeature1Name, processed_study.single_feature_name());
+
+  exp1->clear_feature_association();
+  exp1->mutable_feature_association()->add_enable_feature(kFeature1Name);
+  exp1->mutable_feature_association()->add_enable_feature(kFeature2Name);
+  EXPECT_TRUE(processed_study.Init(&study, false));
+  EXPECT_EQ(std::string(), processed_study.single_feature_name());

[rkaplow, 2016/03/17 15:08:48]

maybe note what this is testing (multiple features make s_f_n unset).

[Alexei Svitkine (slow), 2016/03/17 15:24:59]

Done.

+
+  exp1->clear_feature_association();
+  exp1->mutable_feature_association()->add_enable_feature(kFeature1Name);
+  exp2->mutable_feature_association()->add_enable_feature(kFeature1Name);
+  exp3->mutable_feature_association()->add_disable_feature(kFeature1Name);
+  EXPECT_TRUE(processed_study.Init(&study, false));
+  EXPECT_EQ(kFeature1Name, processed_study.single_feature_name());
+
+  // Setting a different feature name on exp2 should cause |single_feature_name|
+  // to be not set.
+  exp2->mutable_feature_association()->set_enable_feature(0, kFeature2Name);
+  EXPECT_TRUE(processed_study.Init(&study, false));
+  EXPECT_EQ(std::string(), processed_study.single_feature_name());
+}
+
 TEST_F(VariationsSeedProcessorTest, ProcessedStudyAllAssignmentsToOneGroup) {
   Study study;
   study.set_default_experiment_name("def");
   AddExperiment("def", 100, &study);
 
   ProcessedStudy processed_study;
   EXPECT_TRUE(processed_study.Init(&study, false));
   EXPECT_TRUE(processed_study.all_assignments_to_one_group());
 
   AddExperiment("abc", 0, &study);
@@ skipping 234 matching lines @@
     const char* disable_features_command_line;
     OneHundredPercentGroup one_hundred_percent_group;
 
     const char* expected_group;
     bool expected_feature_state;
     bool expected_trial_activated;
   } test_cases[] = {
       // Check what happens without and command-line forcing flags - that the
       // |one_hundred_percent_group| gets correctly selected and does the right
       // thing w.r.t. to affecting the feature / activating the trial.
-      {kFeatureOffByDefault, "", "", DEFAULT_GROUP, kDefaultGroup, false,
-       false},
+      {kFeatureOffByDefault, "", "", DEFAULT_GROUP, kDefaultGroup, false, true},
       {kFeatureOffByDefault, "", "", ENABLE_GROUP, kEnabledGroup, true, true},
       {kFeatureOffByDefault, "", "", DISABLE_GROUP, kDisabledGroup, false,
        true},
 
       // Do the same as above, but for kFeatureOnByDefault feature.
-      {kFeatureOnByDefault, "", "", DEFAULT_GROUP, kDefaultGroup, true, false},
+      {kFeatureOnByDefault, "", "", DEFAULT_GROUP, kDefaultGroup, true, true},
       {kFeatureOnByDefault, "", "", ENABLE_GROUP, kEnabledGroup, true, true},
       {kFeatureOnByDefault, "", "", DISABLE_GROUP, kDisabledGroup, false, true},
 
       // Test forcing each feature on and off through the command-line and that
       // the correct associated experiment gets chosen.
       {kFeatureOffByDefault, kFeatureOffByDefault.name, "", DEFAULT_GROUP,
        kForcedOnGroup, true, true},
       {kFeatureOffByDefault, "", kFeatureOffByDefault.name, DEFAULT_GROUP,
        kForcedOffGroup, false, true},
       {kFeatureOnByDefault, kFeatureOnByDefault.name, "", DEFAULT_GROUP,
@@ skipping 68 matching lines @@
     // depending on the expected values.
     EXPECT_FALSE(base::FieldTrialList::IsTrialActive(study.name()));
     EXPECT_EQ(test_case.expected_feature_state,
               base::FeatureList::IsEnabled(test_case.feature));
     EXPECT_EQ(test_case.expected_trial_activated,
               base::FieldTrialList::IsTrialActive(study.name()));
   }
 }
 
 }  // namespace variations