ash/metrics/task_switch_time_tracker_unittest.cc

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   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 "ash/metrics/task_switch_time_tracker.h"
   6
   7 #include <string>
   8
   9 #include "ash/test/task_switch_time_tracker_test_api.h"
  10 #include "base/test/histogram_tester.h"
  11 #include "testing/gtest/include/gtest/gtest.h"
  12
  13 namespace ash {
  14
  15 namespace {
  16
  17 // A dummy histogram name.
  18 const std::string kHistogramName = "Dummy.Histogram";
  19
  20 }  // namespace
  21
  22 class TaskSwitchTimeTrackerTest : public testing::Test {
  23  public:
  24   TaskSwitchTimeTrackerTest();
  25   ~TaskSwitchTimeTrackerTest() override;
  26
  27   // testing::Test:
  28   void SetUp() override;
  29   void TearDown() override;
  30
  31   // Wrapper to the test targets OnTaskSwitch() method.
  32   void OnTaskSwitch();
  33
  34   TaskSwitchTimeTracker* time_tracker() {
  35     return time_tracker_test_api_->time_tracker();
  36   }
  37
  38  protected:
  39   // Used to verify recorded histogram data.
  40   scoped_ptr<base::HistogramTester> histogram_tester_;
  41
  42   // A Test API that wraps the test target.
  43   scoped_ptr<test::TaskSwitchTimeTrackerTestAPI> time_tracker_test_api_;
  44
  45  private:
  46   DISALLOW_COPY_AND_ASSIGN(TaskSwitchTimeTrackerTest);
  47 };
  48
  49 TaskSwitchTimeTrackerTest::TaskSwitchTimeTrackerTest() {
  50 }
  51
  52 TaskSwitchTimeTrackerTest::~TaskSwitchTimeTrackerTest() {
  53 }
  54
  55 void TaskSwitchTimeTrackerTest::SetUp() {
  56   testing::Test::SetUp();
  57
  58   histogram_tester_.reset(new base::HistogramTester());
  59   time_tracker_test_api_.reset(
  60       new test::TaskSwitchTimeTrackerTestAPI(kHistogramName));
  61   // The TaskSwitchTimeTracker interprets a value of base::TimeTicks() as if the
  62   // |last_action_time_| has not been set.
  63   time_tracker_test_api_->Advance(base::TimeDelta::FromMilliseconds(1));
  64 }
  65
  66 void TaskSwitchTimeTrackerTest::TearDown() {
  67   testing::Test::TearDown();
  68   time_tracker_test_api_.reset();
  69   histogram_tester_.reset();
  70 }
  71
  72 void TaskSwitchTimeTrackerTest::OnTaskSwitch() {
  73   time_tracker()->OnTaskSwitch();
  74 }
  75
  76 // Verifies TaskSwitchTimeTracker::HasLastActionTime() returns false after
  77 // construction.
  78 TEST_F(TaskSwitchTimeTrackerTest,
  79        HasLastActionTimeShouldBeFalseAfterConstruction) {
  80   EXPECT_FALSE(time_tracker_test_api_->HasLastActionTime());
  81 }
  82
  83 // Verifies TaskSwitchTimeTracker::HasLastActionTime() returns true after the
  84 // first call to TaskSwitchTimeTracker::OnTaskSwitch() and no histogram data was
  85 // recorded.
  86 TEST_F(TaskSwitchTimeTrackerTest,
  87        HasLastActionTimeShouldBeTrueAfterOnTaskSwitch) {
  88   OnTaskSwitch();
  89   histogram_tester_->ExpectTotalCount(kHistogramName, 0);
  90 }
  91
  92 // Verfies that the histogram data is recorded in the correct buckets.
  93 TEST_F(TaskSwitchTimeTrackerTest, RecordAfterTwoTaskSwitches) {
  94   OnTaskSwitch();
  95
  96   time_tracker_test_api_->Advance(base::TimeDelta::FromMilliseconds(2));
  97   OnTaskSwitch();
  98   histogram_tester_->ExpectTotalCount(kHistogramName, 1);
  99   histogram_tester_->ExpectBucketCount(kHistogramName, 0, 1);
 100
 101   time_tracker_test_api_->Advance(base::TimeDelta::FromSeconds(1));
 102   OnTaskSwitch();
 103   histogram_tester_->ExpectTotalCount(kHistogramName, 2);
 104   histogram_tester_->ExpectBucketCount(kHistogramName, 1, 1);
 105 }
 106
 107 }  // namespace ash