base/test/histogram_tester_unittest.cc

   1 // Copyright 2014 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 "base/test/histogram_tester.h"
   6
   7 #include "base/memory/scoped_ptr.h"
   8 #include "base/metrics/histogram_macros.h"
   9 #include "base/metrics/histogram_samples.h"
  10 #include "testing/gmock/include/gmock/gmock.h"
  11 #include "testing/gtest/include/gtest/gtest.h"
  12
  13 using ::testing::ElementsAre;
  14
  15 namespace {
  16
  17 const char kHistogram1[] = "Test1";
  18 const char kHistogram2[] = "Test2";
  19 const char kHistogram3[] = "Test3";
  20 const char kHistogram4[] = "Test4";
  21 const char kHistogram5[] = "Test5";
  22
  23 }  // namespace
  24
  25 namespace base {
  26
  27 typedef testing::Test HistogramTesterTest;
  28
  29 TEST_F(HistogramTesterTest, Scope) {
  30   // Record a histogram before the creation of the recorder.
  31   UMA_HISTOGRAM_BOOLEAN(kHistogram1, true);
  32
  33   HistogramTester tester;
  34
  35   // Verify that no histogram is recorded.
  36   tester.ExpectTotalCount(kHistogram1, 0);
  37
  38   // Record a histogram after the creation of the recorder.
  39   UMA_HISTOGRAM_BOOLEAN(kHistogram1, true);
  40
  41   // Verify that one histogram is recorded.
  42   scoped_ptr<HistogramSamples> samples(
  43       tester.GetHistogramSamplesSinceCreation(kHistogram1));
  44   EXPECT_TRUE(samples);
  45   EXPECT_EQ(1, samples->TotalCount());
  46 }
  47
  48 TEST_F(HistogramTesterTest, GetHistogramSamplesSinceCreationNotNull) {
  49   // Chose the histogram name uniquely, to ensure nothing was recorded for it so
  50   // far.
  51   static const char kHistogram[] =
  52       "GetHistogramSamplesSinceCreationNotNullHistogram";
  53   HistogramTester tester;
  54
  55   // Verify that the returned samples are empty but not null.
  56   scoped_ptr<HistogramSamples> samples(
  57       tester.GetHistogramSamplesSinceCreation(kHistogram1));
  58   EXPECT_TRUE(samples);
  59   tester.ExpectTotalCount(kHistogram, 0);
  60 }
  61
  62 TEST_F(HistogramTesterTest, TestUniqueSample) {
  63   HistogramTester tester;
  64
  65   // Record into a sample thrice
  66   UMA_HISTOGRAM_COUNTS_100(kHistogram2, 2);
  67   UMA_HISTOGRAM_COUNTS_100(kHistogram2, 2);
  68   UMA_HISTOGRAM_COUNTS_100(kHistogram2, 2);
  69
  70   tester.ExpectUniqueSample(kHistogram2, 2, 3);
  71 }
  72
  73 TEST_F(HistogramTesterTest, TestBucketsSample) {
  74   HistogramTester tester;
  75
  76   // Record into a sample twice
  77   UMA_HISTOGRAM_COUNTS_100(kHistogram3, 2);
  78   UMA_HISTOGRAM_COUNTS_100(kHistogram3, 2);
  79   UMA_HISTOGRAM_COUNTS_100(kHistogram3, 2);
  80   UMA_HISTOGRAM_COUNTS_100(kHistogram3, 2);
  81   UMA_HISTOGRAM_COUNTS_100(kHistogram3, 3);
  82
  83   tester.ExpectBucketCount(kHistogram3, 2, 4);
  84   tester.ExpectBucketCount(kHistogram3, 3, 1);
  85
  86   tester.ExpectTotalCount(kHistogram3, 5);
  87 }
  88
  89 TEST_F(HistogramTesterTest, TestBucketsSampleWithScope) {
  90   // Record into a sample twice, once before the tester creation and once after.
  91   UMA_HISTOGRAM_COUNTS_100(kHistogram4, 2);
  92
  93   HistogramTester tester;
  94   UMA_HISTOGRAM_COUNTS_100(kHistogram4, 3);
  95
  96   tester.ExpectBucketCount(kHistogram4, 2, 0);
  97   tester.ExpectBucketCount(kHistogram4, 3, 1);
  98
  99   tester.ExpectTotalCount(kHistogram4, 1);
 100 }
 101
 102 TEST_F(HistogramTesterTest, TestGetAllSamples) {
 103   HistogramTester tester;
 104   UMA_HISTOGRAM_ENUMERATION(kHistogram5, 2, 5);
 105   UMA_HISTOGRAM_ENUMERATION(kHistogram5, 3, 5);
 106   UMA_HISTOGRAM_ENUMERATION(kHistogram5, 3, 5);
 107   UMA_HISTOGRAM_ENUMERATION(kHistogram5, 5, 5);
 108
 109   EXPECT_THAT(tester.GetAllSamples(kHistogram5),
 110               ElementsAre(Bucket(2, 1), Bucket(3, 2), Bucket(5, 1)));
 111 }
 112
 113 }  // namespace base