Simulate field trial assignments with new variations seed.

components/variations/variations_seed_simulator_unittest.cc

Index: components/variations/variations_seed_simulator_unittest.cc
===================================================================
--- components/variations/variations_seed_simulator_unittest.cc	(revision 0)
+++ components/variations/variations_seed_simulator_unittest.cc	(working copy)
@@ -0,0 +1,287 @@
+// 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_simulator.h"
+
+#include <map>
+
+#include "components/variations/processed_study.h"
+#include "components/variations/proto/study.pb.h"
+#include "components/variations/variations_associated_data.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace chrome_variations {
+
+namespace {
+
+// An implementation of EntropyProvider that always returns a specific entropy
+// value, regardless of field trial.
+class TestEntropyProvider : public base::FieldTrial::EntropyProvider {
+ public:
+  explicit TestEntropyProvider(double entropy_value)
+      : entropy_value_(entropy_value) {}
+  virtual ~TestEntropyProvider() {}
+
+  // base::FieldTrial::EntropyProvider implementation:
+  virtual double GetEntropyForTrial(const std::string& trial_name,
+                                    uint32 randomization_seed) const OVERRIDE {
+    return entropy_value_;
+  }
+
+ private:
+  const double entropy_value_;
+
+  DISALLOW_COPY_AND_ASSIGN(TestEntropyProvider);
+};
+
+// Creates and activates a single-group field trial with name |trial_name| and
+// group |group_name| and variations |params| (if not NULL).
+void CreateTrial(const std::string& trial_name,
+                 const std::string& group_name,
+                 const std::map<std::string, std::string>* params) {
+  base::FieldTrialList::CreateFieldTrial(trial_name, group_name);
+  if (params != NULL)
+    AssociateVariationParams(trial_name, group_name, *params);
+  base::FieldTrialList::FindFullName(trial_name);
+}
+
+// Creates a study with the given |study_name| and |consistency|.
+Study CreateStudy(const std::string& study_name,
+                  Study_Consistency consistency) {
+  Study study;
+  study.set_name(study_name);
+  study.set_consistency(consistency);
+  return study;
+}
+
+// Adds an experiment to |study| with the specified |experiment_name| and
+// |probability| values and sets it as the study's default experiment.
+Study_Experiment* AddExperiment(const std::string& experiment_name,
+                                int probability,
+                                Study* study) {
+  Study_Experiment* experiment = study->add_experiment();
+  experiment->set_name(experiment_name);
+  experiment->set_probability_weight(probability);
+  study->set_default_experiment_name(experiment_name);
+  return experiment;
+}
+
+// Add an experiment param with |param_name| and |param_value| to |experiment|.
+Study_Experiment_Param* AddExperimentParam(const std::string& param_name,
+                                           const std::string& param_value,
+                                           Study_Experiment* experiment) {
+  Study_Experiment_Param* param = experiment->add_param();
+  param->set_name(param_name);
+  param->set_value(param_value);
+  return param;
+}
+
+// Uses a VariationsSeedSimulator to simulate the differences between |studies|
+// and the current field trial state.
+int SimulateDifferences(const std::vector<ProcessedStudy>& studies) {
+  TestEntropyProvider provider(0.5);
+  VariationsSeedSimulator seed_simulator(provider);
+  return seed_simulator.ComputeDifferences(studies);
+}
+
+class VariationsSeedSimulatorTest : public ::testing::Test {
+ public:
+  VariationsSeedSimulatorTest() : field_trial_list_(NULL) {
+  }
+
+  virtual ~VariationsSeedSimulatorTest() {
+    // Ensure that the maps are cleared between tests, since they are stored as
+    // process singletons.
+    testing::ClearAllVariationIDs();
+    testing::ClearAllVariationParams();
+  }
+
+ private:
+  base::FieldTrialList field_trial_list_;
+
+  DISALLOW_COPY_AND_ASSIGN(VariationsSeedSimulatorTest);
+};
+
+}  // namespace
+
+TEST_F(VariationsSeedSimulatorTest, PermanentNoChanges) {
+  CreateTrial("A", "B", NULL);
+
+  std::vector<ProcessedStudy> processed_studies;
+  Study study = CreateStudy("A", Study_Consistency_PERMANENT);
+  AddExperiment("B", 100, &study);
+
+  std::vector<ProcessedStudy> studies;
+  EXPECT_TRUE(ProcessedStudy::ValidateAndAppendStudy(&study, false, &studies));
+
+  EXPECT_EQ(0, SimulateDifferences(studies));
+}
+
+TEST_F(VariationsSeedSimulatorTest, PermanentGroupChange) {
+  CreateTrial("A", "B", NULL);
+
+  Study study = CreateStudy("A", Study_Consistency_PERMANENT);
+  AddExperiment("C", 100, &study);
+
+  std::vector<ProcessedStudy> studies;
+  EXPECT_TRUE(ProcessedStudy::ValidateAndAppendStudy(&study, false, &studies));
+
+  EXPECT_EQ(1, SimulateDifferences(studies));
+}
+
+TEST_F(VariationsSeedSimulatorTest, PermanentExpired) {
+  CreateTrial("A", "B", NULL);
+
+  Study study = CreateStudy("A", Study_Consistency_PERMANENT);
+  AddExperiment("B", 1, &study);
+  AddExperiment("C", 0, &study);
+
+  std::vector<ProcessedStudy> studies;
+  EXPECT_TRUE(ProcessedStudy::ValidateAndAppendStudy(&study, true, &studies));
+  EXPECT_TRUE(studies[0].is_expired());
+
+  // There should be a difference because the study is expired, which should
+  // result in the default group "D" being chosen.
+  EXPECT_EQ(1, SimulateDifferences(studies));
+}
+
+TEST_F(VariationsSeedSimulatorTest, SessionRandomized) {
+  CreateTrial("A", "B", NULL);
+
+  Study study = CreateStudy("A", Study_Consistency_SESSION);
+  AddExperiment("B", 1, &study);
+  AddExperiment("C", 1, &study);
+  AddExperiment("D", 1, &study);
+
+  std::vector<ProcessedStudy> studies;
+  EXPECT_TRUE(ProcessedStudy::ValidateAndAppendStudy(&study, false, &studies));
+
+  // There should be no differences, since a session randomized study can result
+  // in any of the groups being chosen on startup.
+  EXPECT_EQ(0, SimulateDifferences(studies));
+}
+
+TEST_F(VariationsSeedSimulatorTest, SessionRandomizedGroupRemoved) {
+  CreateTrial("A", "B", NULL);
+
+  Study study = CreateStudy("A", Study_Consistency_SESSION);
+  AddExperiment("C", 1, &study);
+  AddExperiment("D", 1, &study);
+
+  std::vector<ProcessedStudy> studies;
+  EXPECT_TRUE(ProcessedStudy::ValidateAndAppendStudy(&study, false, &studies));
+
+  // There should be a difference since there is no group "B" in the new config.
+  EXPECT_EQ(1, SimulateDifferences(studies));
+}
+
+TEST_F(VariationsSeedSimulatorTest, SessionRandomizedGroupProbabilityZero) {
+  CreateTrial("A", "B", NULL);
+
+  Study study = CreateStudy("A", Study_Consistency_SESSION);
+  AddExperiment("B", 0, &study);
+  AddExperiment("C", 1, &study);
+  AddExperiment("D", 1, &study);
+
+  std::vector<ProcessedStudy> studies;
+  EXPECT_TRUE(ProcessedStudy::ValidateAndAppendStudy(&study, false, &studies));
+
+  // There should be a difference since there is group "B" has probability 0.
+  EXPECT_EQ(1, SimulateDifferences(studies));
+}
+
+TEST_F(VariationsSeedSimulatorTest, SessionRandomizedExpired) {
+  CreateTrial("A", "B", NULL);
+
+  Study study = CreateStudy("A", Study_Consistency_SESSION);
+  AddExperiment("B", 1, &study);
+  AddExperiment("C", 1, &study);
+  AddExperiment("D", 1, &study);
+
+  std::vector<ProcessedStudy> studies;
+  EXPECT_TRUE(ProcessedStudy::ValidateAndAppendStudy(&study, true, &studies));
+  EXPECT_TRUE(studies[0].is_expired());
+
+  // There should be a difference because the study is expired, which should
+  // result in the default group "D" being chosen.
+  EXPECT_EQ(1, SimulateDifferences(studies));
+}
+
+TEST_F(VariationsSeedSimulatorTest, ParamsUnchanged) {
+  std::map<std::string, std::string> params;
+  params["p1"] = "x";
+  params["p2"] = "y";
+  params["p3"] = "z";
+  CreateTrial("A", "B", &params);
+
+  std::vector<ProcessedStudy> processed_studies;
+  Study study = CreateStudy("A", Study_Consistency_PERMANENT);
+  Study_Experiment* experiment = AddExperiment("B", 100, &study);
+  AddExperimentParam("p2", "y", experiment);
+  AddExperimentParam("p1", "x", experiment);
+  AddExperimentParam("p3", "z", experiment);
+
+  std::vector<ProcessedStudy> studies;
+  EXPECT_TRUE(ProcessedStudy::ValidateAndAppendStudy(&study, false, &studies));
+
+  EXPECT_EQ(0, SimulateDifferences(studies));
+}
+
+TEST_F(VariationsSeedSimulatorTest, ParamsChanged) {
+  std::map<std::string, std::string> params;
+  params["p1"] = "x";
+  params["p2"] = "y";
+  params["p3"] = "z";
+  CreateTrial("A", "B", &params);
+
+  std::vector<ProcessedStudy> processed_studies;
+  Study study = CreateStudy("A", Study_Consistency_PERMANENT);
+  Study_Experiment* experiment = AddExperiment("B", 100, &study);
+  AddExperimentParam("p2", "test", experiment);
+  AddExperimentParam("p1", "x", experiment);
+  AddExperimentParam("p3", "z", experiment);
+
+  std::vector<ProcessedStudy> studies;
+  EXPECT_TRUE(ProcessedStudy::ValidateAndAppendStudy(&study, false, &studies));
+
+  // The param lists differ.
+  EXPECT_EQ(1, SimulateDifferences(studies));
+}
+
+TEST_F(VariationsSeedSimulatorTest, ParamsRemoved) {
+  std::map<std::string, std::string> params;
+  params["p1"] = "x";
+  params["p2"] = "y";
+  params["p3"] = "z";
+  CreateTrial("A", "B", &params);
+
+  std::vector<ProcessedStudy> processed_studies;
+  Study study = CreateStudy("A", Study_Consistency_PERMANENT);
+  AddExperiment("B", 100, &study);
+
+  std::vector<ProcessedStudy> studies;
+  EXPECT_TRUE(ProcessedStudy::ValidateAndAppendStudy(&study, false, &studies));
+
+  // The current group has params, but the new config doesn't have any.
+  EXPECT_EQ(1, SimulateDifferences(studies));
+}
+
+TEST_F(VariationsSeedSimulatorTest, ParamsAdded) {
+  CreateTrial("A", "B", NULL);
+
+  std::vector<ProcessedStudy> processed_studies;
+  Study study = CreateStudy("A", Study_Consistency_PERMANENT);
+  Study_Experiment* experiment = AddExperiment("B", 100, &study);
+  AddExperimentParam("p2", "y", experiment);
+  AddExperimentParam("p1", "x", experiment);
+  AddExperimentParam("p3", "z", experiment);
+
+  std::vector<ProcessedStudy> studies;
+  EXPECT_TRUE(ProcessedStudy::ValidateAndAppendStudy(&study, false, &studies));
+
+  // The current group has no params, but the config has added some.
+  EXPECT_EQ(1, SimulateDifferences(studies));
+}
+
+}  // namespace chrome_variations