chrome/browser/chrome_browser_field_trials_unittest.cc

   1 // Copyright 2022 The Chromium Authors
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/chrome_browser_field_trials.h"
   6
   7 #include <memory>
   8
   9 #include "base/feature_list.h"
  10 #include "components/prefs/testing_pref_service.h"
  11 #include "components/ukm/ukm_recorder_impl.h"
  12 #include "testing/gtest/include/gtest/gtest.h"
  13
  14 #if BUILDFLAG(IS_WIN) || BUILDFLAG(IS_ANDROID)
  15 TEST(ChromeBrowserFieldTrialsTest, SamplingTrials) {
  16   TestingPrefServiceSimple local_state;
  17   ChromeBrowserFieldTrials chrome_browser_field_trials(&local_state);
  18
  19   const char kSamplingTrialName[] = "MetricsAndCrashSampling";
  20 #if BUILDFLAG(IS_ANDROID)
  21   const char kPostFREFixSamplingTrialName[] =
  22       "PostFREFixMetricsAndCrashSampling";
  23 #endif  // BUILDFLAG(IS_ANDROID)
  24   const char kUkmSamplingTrialName[] = "UkmSamplingRate";
  25
  26   // Verify that initially, sampling trials do not exist.
  27   EXPECT_FALSE(base::FieldTrialList::TrialExists(kSamplingTrialName));
  28 #if BUILDFLAG(IS_ANDROID)
  29   EXPECT_FALSE(base::FieldTrialList::TrialExists(kPostFREFixSamplingTrialName));
  30 #endif  // BUILDFLAG(IS_ANDROID)
  31   EXPECT_FALSE(base::FieldTrialList::TrialExists(kUkmSamplingTrialName));
  32
  33   // Call SetUpClientSideFieldTrials(), which should create fallback
  34   // sampling trials since they do not exist yet.
  35   variations::EntropyProviders entropy_providers("client_id", {0, 8000});
  36   auto feature_list = std::make_unique<base::FeatureList>();
  37   chrome_browser_field_trials.SetUpClientSideFieldTrials(
  38       /*has_seed=*/false, entropy_providers, feature_list.get());
  39
  40   // Verify that the sampling trials were created.
  41   EXPECT_TRUE(base::FieldTrialList::TrialExists(kSamplingTrialName));
  42 #if BUILDFLAG(IS_ANDROID)
  43   EXPECT_TRUE(base::FieldTrialList::TrialExists(kPostFREFixSamplingTrialName));
  44 #endif  // BUILDFLAG(IS_ANDROID)
  45   EXPECT_TRUE(base::FieldTrialList::TrialExists(kUkmSamplingTrialName));
  46
  47   // Call SetUpClientSideFieldTrials() again. This should be a no-op,
  48   // since the sampling trials already exist. If the trials are created again,
  49   // a CHECK will be triggered and this will crash.
  50   chrome_browser_field_trials.SetUpClientSideFieldTrials(
  51       /*has_seed=*/false, entropy_providers, feature_list.get());
  52 }
  53 #endif  // BUILDFLAG(IS_WIN) || BUILDFLAG(IS_ANDROID)