Add variations params api to get params from features.

components/variations/variations_associated_data_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_associated_data.h"
 
+#include "base/feature_list.h"
 #include "base/macros.h"
 #include "base/metrics/field_trial.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace variations {
 
 namespace {
 
 const VariationID TEST_VALUE_A = 3300200;
 const VariationID TEST_VALUE_B = 3300201;
 
 // Convenience helper to retrieve the variations::VariationID for a FieldTrial.
 // Note that this will do the group assignment in |trial| if not already done.
 VariationID GetIDForTrial(IDCollectionKey key, base::FieldTrial* trial) {
   return GetGoogleVariationID(key, trial->trial_name(), trial->group_name());
 }
 
 // Call FieldTrialList::FactoryGetFieldTrial() with a future expiry date.
 scoped_refptr<base::FieldTrial> CreateFieldTrial(
     const std::string& trial_name,
     int total_probability,
     const std::string& default_group_name,
     int* default_group_number) {
   return base::FieldTrialList::FactoryGetFieldTrial(
       trial_name, total_probability, default_group_name,
       base::FieldTrialList::kNoExpirationYear, 1, 1,
       base::FieldTrial::SESSION_RANDOMIZED, default_group_number);
 }
 
+void CreateFeatureWithTrial(const base::Feature& feature,
+                            base::FeatureList::OverrideState override_state,
+                            scoped_refptr<base::FieldTrial> trial) {

[Alexei Svitkine (slow), 2016/05/03 17:04:25]

Nit: Just pass by FieldTrial*.

[jwd, 2016/05/03 20:12:27]

Done.

+  base::FeatureList::ClearInstanceForTesting();
+  std::unique_ptr<base::FeatureList> feature_list(new base::FeatureList);
+  feature_list->RegisterFieldTrialOverride(feature.name, override_state,
+                                           trial.get());
+  base::FeatureList::SetInstance(std::move(feature_list));
+}
+
 }  // namespace
 
 class VariationsAssociatedDataTest : public ::testing::Test {
  public:
   VariationsAssociatedDataTest() : field_trial_list_(NULL) {
   }
 
   ~VariationsAssociatedDataTest() override {
     // Ensure that the maps are cleared between tests, since they are stored as
     // process singletons.
@@ skipping 293 matching lines @@
   ASSERT_FALSE(base::FieldTrialList::IsTrialActive(kTrialName));
   scoped_refptr<base::FieldTrial> trial(
       CreateFieldTrial(kTrialName, 100, "A", NULL));
   ASSERT_FALSE(base::FieldTrialList::IsTrialActive(kTrialName));
 
   std::map<std::string, std::string> params;
   EXPECT_EQ(std::string(), GetVariationParamValue(kTrialName, "x"));
   ASSERT_TRUE(base::FieldTrialList::IsTrialActive(kTrialName));
 }
 
+TEST_F(VariationsAssociatedDataTest, GetVariationParamsByFeature) {
+  const std::string kTrialName = "GetVariationParamsByFeature";
+
+  std::map<std::string, std::string> params;
+  params["x"] = "1";
+  variations::AssociateVariationParams(kTrialName, "A", params);
+  scoped_refptr<base::FieldTrial> trial(
+      CreateFieldTrial(kTrialName, 100, "A", NULL));
+
+  const base::Feature kFeature{"TestFeature",
+                               base::FEATURE_DISABLED_BY_DEFAULT};
+
+  CreateFeatureWithTrial(kFeature, base::FeatureList::OVERRIDE_ENABLE_FEATURE,
+                         trial);
+
+  std::map<std::string, std::string> actualParams;
+  EXPECT_TRUE(GetVariationParamsByFeature(kFeature, &actualParams));
+  EXPECT_EQ(params, actualParams);
+}
+
+TEST_F(VariationsAssociatedDataTest, GetVariationParamValueByFeature) {
+  const std::string kTrialName = "GetVariationParamsByFeature";
+
+  std::map<std::string, std::string> params;
+  params["x"] = "1";
+  variations::AssociateVariationParams(kTrialName, "A", params);
+  scoped_refptr<base::FieldTrial> trial(
+      CreateFieldTrial(kTrialName, 100, "A", NULL));
+
+  const base::Feature kFeature{"TestFeature",
+                               base::FEATURE_DISABLED_BY_DEFAULT};
+
+  CreateFeatureWithTrial(kFeature, base::FeatureList::OVERRIDE_ENABLE_FEATURE,
+                         trial);
+
+  std::map<std::string, std::string> actualParams;
+  EXPECT_EQ(params["x"], GetVariationParamValueByFeature(kFeature, "x"));
+}
+
+TEST_F(VariationsAssociatedDataTest, GetVariationParamsByFeature_Disable) {
+  const std::string kTrialName = "GetVariationParamsByFeature";
+
+  std::map<std::string, std::string> params;
+  params["x"] = "1";
+  variations::AssociateVariationParams(kTrialName, "A", params);
+  scoped_refptr<base::FieldTrial> trial(
+      CreateFieldTrial(kTrialName, 100, "A", NULL));
+
+  const base::Feature kFeature{"TestFeature",
+                               base::FEATURE_DISABLED_BY_DEFAULT};
+
+  CreateFeatureWithTrial(kFeature, base::FeatureList::OVERRIDE_DISABLE_FEATURE,
+                         trial);
+
+  std::map<std::string, std::string> actualParams;
+  EXPECT_FALSE(GetVariationParamsByFeature(kFeature, &actualParams));
+}
+
+TEST_F(VariationsAssociatedDataTest, GetVariationParamValueByFeature_Disable) {
+  const std::string kTrialName = "GetVariationParamsByFeature";
+
+  std::map<std::string, std::string> params;
+  params["x"] = "1";
+  variations::AssociateVariationParams(kTrialName, "A", params);
+  scoped_refptr<base::FieldTrial> trial(
+      CreateFieldTrial(kTrialName, 100, "A", NULL));
+
+  const base::Feature kFeature{"TestFeature",

[Alexei Svitkine (slow), 2016/05/03 17:04:25]

Nit: Maybe move this to the top of the function below kTrialName so that the
constants are together.

[jwd, 2016/05/03 20:12:27]

Done.

+                               base::FEATURE_DISABLED_BY_DEFAULT};
+
+  CreateFeatureWithTrial(kFeature, base::FeatureList::OVERRIDE_DISABLE_FEATURE,
+                         trial);
+
+  std::map<std::string, std::string> actualParams;
+  EXPECT_EQ(std::string(), GetVariationParamValueByFeature(kFeature, "x"));
+}
+
 }  // namespace variations