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.h"
   9 #include "base/metrics/histogram_samples.h"
  10 #include "testing/gtest/include/gtest/gtest.h"
  11
  12 namespace base {
  13
  14 const std::string kHistogram1 = "Test1";
  15 const std::string kHistogram2 = "Test2";
  16 const std::string kHistogram3 = "Test3";
  17 const std::string kHistogram4 = "Test4";
  18
  19 typedef testing::Test HistogramTesterTest;
  20
  21 TEST_F(HistogramTesterTest, Scope) {
  22   // Record a histogram before the creation of the recorder.
  23   UMA_HISTOGRAM_BOOLEAN(kHistogram1, true);
  24
  25   HistogramTester tester;
  26
  27   // Verify that no histogram is recorded.
  28   scoped_ptr<HistogramSamples> samples(
  29       tester.GetHistogramSamplesSinceCreation(kHistogram1));
  30   EXPECT_FALSE(samples);
  31
  32   // Record a histogram after the creation of the recorder.
  33   UMA_HISTOGRAM_BOOLEAN(kHistogram1, true);
  34
  35   // Verify that one histogram is recorded.
  36   samples = tester.GetHistogramSamplesSinceCreation(kHistogram1);
  37   EXPECT_TRUE(samples);
  38   EXPECT_EQ(1, samples->TotalCount());
  39 }
  40
  41 TEST_F(HistogramTesterTest, TestUniqueSample) {
  42   HistogramTester tester;
  43
  44   // Record into a sample thrice
  45   UMA_HISTOGRAM_COUNTS_100(kHistogram2, 2);
  46   UMA_HISTOGRAM_COUNTS_100(kHistogram2, 2);
  47   UMA_HISTOGRAM_COUNTS_100(kHistogram2, 2);
  48
  49   tester.ExpectUniqueSample(kHistogram2, 2, 3);
  50 }
  51
  52 TEST_F(HistogramTesterTest, TestBucketsSample) {
  53   HistogramTester tester;
  54
  55   // Record into a sample twice
  56   UMA_HISTOGRAM_COUNTS_100(kHistogram3, 2);
  57   UMA_HISTOGRAM_COUNTS_100(kHistogram3, 2);
  58   UMA_HISTOGRAM_COUNTS_100(kHistogram3, 2);
  59   UMA_HISTOGRAM_COUNTS_100(kHistogram3, 2);
  60   UMA_HISTOGRAM_COUNTS_100(kHistogram3, 3);
  61
  62   tester.ExpectBucketCount(kHistogram3, 2, 4);
  63   tester.ExpectBucketCount(kHistogram3, 3, 1);
  64
  65   tester.ExpectTotalCount(kHistogram3, 5);
  66 }
  67
  68 TEST_F(HistogramTesterTest, TestBucketsSampleWithScope) {
  69   // Record into a sample twice, once before the tester creation and once after.
  70   UMA_HISTOGRAM_COUNTS_100(kHistogram4, 2);
  71
  72   HistogramTester tester;
  73   UMA_HISTOGRAM_COUNTS_100(kHistogram4, 3);
  74
  75   tester.ExpectBucketCount(kHistogram4, 2, 0);
  76   tester.ExpectBucketCount(kHistogram4, 3, 1);
  77
  78   tester.ExpectTotalCount(kHistogram4, 1);
  79 }
  80
  81 }  // namespace base