1 // Copyright 2017 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/metrics/single_sample_metrics.h"
6
7 #include "base/metrics/dummy_histogram.h"
8 #include "base/test/gtest_util.h"
9 #include "base/test/metrics/histogram_tester.h"
10 #include "testing/gtest/include/gtest/gtest.h"
11
12 namespace base {
13
14 namespace {
15
16 const HistogramBase::Sample kMin = 1;
17 const HistogramBase::Sample kMax = 10;
18 const uint32_t kBucketCount = 10;
19 const char kMetricName[] = "Single.Sample.Metric";
20
21 class SingleSampleMetricsTest : public testing::Test {
22 public:
23 SingleSampleMetricsTest() = default;
24
~SingleSampleMetricsTest()25 ~SingleSampleMetricsTest() override {
26 // Ensure we cleanup after ourselves.
27 SingleSampleMetricsFactory::DeleteFactoryForTesting();
28 }
29
30 private:
31 DISALLOW_COPY_AND_ASSIGN(SingleSampleMetricsTest);
32 };
33
34 } // namespace
35
TEST_F(SingleSampleMetricsTest,DefaultFactoryGetSet)36 TEST_F(SingleSampleMetricsTest, DefaultFactoryGetSet) {
37 SingleSampleMetricsFactory* factory = SingleSampleMetricsFactory::Get();
38 ASSERT_TRUE(factory);
39
40 // Same factory should be returned evermore.
41 EXPECT_EQ(factory, SingleSampleMetricsFactory::Get());
42
43 // Setting a factory after the default has been instantiated should fail.
44 EXPECT_DCHECK_DEATH(SingleSampleMetricsFactory::SetFactory(nullptr));
45 }
46
TEST_F(SingleSampleMetricsTest,CustomFactoryGetSet)47 TEST_F(SingleSampleMetricsTest, CustomFactoryGetSet) {
48 auto factory = std::make_unique<DefaultSingleSampleMetricsFactory>();
49 SingleSampleMetricsFactory* factory_raw = factory.get();
50 SingleSampleMetricsFactory::SetFactory(std::move(factory));
51 EXPECT_EQ(factory_raw, SingleSampleMetricsFactory::Get());
52 }
53
TEST_F(SingleSampleMetricsTest,DefaultSingleSampleMetricNoValue)54 TEST_F(SingleSampleMetricsTest, DefaultSingleSampleMetricNoValue) {
55 SingleSampleMetricsFactory* factory = SingleSampleMetricsFactory::Get();
56
57 HistogramTester tester;
58 std::unique_ptr<SingleSampleMetric> metric =
59 factory->CreateCustomCountsMetric(kMetricName, kMin, kMax, kBucketCount);
60 metric.reset();
61
62 // Verify that no sample is recorded if SetSample() is never called.
63 tester.ExpectTotalCount(kMetricName, 0);
64 }
65
TEST_F(SingleSampleMetricsTest,DefaultSingleSampleMetricWithValue)66 TEST_F(SingleSampleMetricsTest, DefaultSingleSampleMetricWithValue) {
67 SingleSampleMetricsFactory* factory = SingleSampleMetricsFactory::Get();
68
69 HistogramTester tester;
70 std::unique_ptr<SingleSampleMetric> metric =
71 factory->CreateCustomCountsMetric(kMetricName, kMin, kMax, kBucketCount);
72
73 const HistogramBase::Sample kLastSample = 9;
74 metric->SetSample(1);
75 metric->SetSample(3);
76 metric->SetSample(5);
77 metric->SetSample(kLastSample);
78 metric.reset();
79
80 // Verify only the last sample sent to SetSample() is recorded.
81 tester.ExpectUniqueSample(kMetricName, kLastSample, 1);
82
83 // Verify construction implicitly by requesting a histogram with the same
84 // parameters; this test relies on the fact that histogram objects are unique
85 // per name. Different parameters will result in a Dummy histogram returned.
86 EXPECT_EQ(
87 DummyHistogram::GetInstance(),
88 Histogram::FactoryGet(kMetricName, 1, 3, 3, HistogramBase::kNoFlags));
89 EXPECT_NE(DummyHistogram::GetInstance(),
90 Histogram::FactoryGet(kMetricName, kMin, kMax, kBucketCount,
91 HistogramBase::kUmaTargetedHistogramFlag));
92 }
93
TEST_F(SingleSampleMetricsTest,MultipleMetricsAreDistinct)94 TEST_F(SingleSampleMetricsTest, MultipleMetricsAreDistinct) {
95 SingleSampleMetricsFactory* factory = SingleSampleMetricsFactory::Get();
96
97 HistogramTester tester;
98 std::unique_ptr<SingleSampleMetric> metric =
99 factory->CreateCustomCountsMetric(kMetricName, kMin, kMax, kBucketCount);
100 std::unique_ptr<SingleSampleMetric> metric2 =
101 factory->CreateCustomCountsMetric(kMetricName, kMin, kMax, kBucketCount);
102 const char kMetricName2[] = "Single.Sample.Metric.2";
103 std::unique_ptr<SingleSampleMetric> metric3 =
104 factory->CreateCustomCountsMetric(kMetricName2, kMin, kMax, kBucketCount);
105
106 const HistogramBase::Sample kSample1 = 5;
107 metric->SetSample(kSample1);
108 metric2->SetSample(kSample1);
109
110 const HistogramBase::Sample kSample2 = 7;
111 metric3->SetSample(kSample2);
112
113 metric.reset();
114 tester.ExpectUniqueSample(kMetricName, kSample1, 1);
115
116 metric2.reset();
117 tester.ExpectUniqueSample(kMetricName, kSample1, 2);
118
119 metric3.reset();
120 tester.ExpectUniqueSample(kMetricName2, kSample2, 1);
121 }
122
123 } // namespace base
124