Log histograms on shutdown when verbose logging is on

base/metrics/statistics_recorder_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stddef.h>
 
 #include <vector>
 
 #include "base/bind.h"
 #include "base/json/json_reader.h"
+#include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/histogram_persistence.h"
 #include "base/metrics/sparse_histogram.h"
 #include "base/metrics/statistics_recorder.h"
 #include "base/values.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 
@@ skipping 33 matching lines @@
     return new Histogram(name, min, max, registered_ranges);
   }
 
   void DeleteHistogram(HistogramBase* histogram) {
     delete histogram;
   }
 
   StatisticsRecorder* statistics_recorder_;
 };
 
+// Class to make sure any manipulations we do to the min log level are
+// contained (i.e., do not affect other unit tests).
+class LogStateSaver {

[Alexei Svitkine (slow), 2016/04/14 20:47:39]

Put this in an anon namespace at the top of the file.

+ public:
+  LogStateSaver() : old_min_log_level_(logging::GetMinLogLevel()) {}
+
+  ~LogStateSaver() {
+    logging::SetMinLogLevel(old_min_log_level_);
+    logging::SetLogAssertHandler(nullptr);
+  }
+
+ private:
+  int old_min_log_level_;
+
+  DISALLOW_COPY_AND_ASSIGN(LogStateSaver);
+};
+
+class StatisticsRecorderLoggingTestBase : public StatisticsRecorderTest {
+ protected:
+  void InitLogOnShutdown() {
+    DCHECK(statistics_recorder_);
+    statistics_recorder_->InitLogOnShutdownWithoutLock();
+  }
+
+ private:
+  LogStateSaver log_state_saver_;

[Alexei Svitkine (slow), 2016/04/14 20:47:39]

Is there any problem doing this unconditionally for every test? If so, you can
then remove all these other test classes.

+};
+
+class StatisticsRecorderLoggingWarningOnStartupTest

[Alexei Svitkine (slow), 2016/04/14 20:47:39]

You don't need to create a separate test harness class for each test. Just use
StatisticsRecorderTest.

+    : public StatisticsRecorderLoggingTestBase {
+ protected:
+  void SetUp() override {
+    logging::SetMinLogLevel(logging::LOG_WARNING);
+    StatisticsRecorderLoggingTestBase::SetUp();
+  }
+};
+
+class StatisticsRecorderLoggingVerboseOnStartupTest
+    : public StatisticsRecorderLoggingTestBase {
+ protected:
+  void SetUp() override {
+    logging::SetMinLogLevel(logging::LOG_VERBOSE);
+    StatisticsRecorderTest::SetUp();
+  }
+
+ private:
+  LogStateSaver log_state_saver_;
+};
+
+
 TEST_F(StatisticsRecorderTest, NotInitialized) {
   UninitializeStatisticsRecorder();
 
   ASSERT_FALSE(StatisticsRecorder::IsActive());
 
   StatisticsRecorder::Histograms registered_histograms;
   std::vector<const BucketRanges*> registered_ranges;
 
   StatisticsRecorder::GetHistograms(&registered_histograms);
   EXPECT_EQ(0u, registered_histograms.size());
@@ skipping 432 matching lines @@
 
   HistogramBase* histogram = Histogram::FactoryGet("TestHistogram", 1, 1000, 10,
                                                    HistogramBase::kNoFlags);
   EXPECT_TRUE(histogram);
   histogram->Add(1);
 
   EXPECT_TRUE(callback_wrapper.called);
   EXPECT_EQ(callback_wrapper.last_histogram_value, 1);
 }
 
+TEST_F(StatisticsRecorderLoggingWarningOnStartupTest,
+       LogOnShutdownNotInitialized) {
+  EXPECT_FALSE(VLOG_IS_ON(1));
+  EXPECT_FALSE(StatisticsRecorder::VLogInitializedForTesting());
+  InitLogOnShutdown();
+  EXPECT_FALSE(StatisticsRecorder::VLogInitializedForTesting());
+}
+
+TEST_F(StatisticsRecorderLoggingWarningOnStartupTest,
+       LogOnShutdownInitializedExplicitly) {
+  EXPECT_FALSE(VLOG_IS_ON(1));
+  EXPECT_FALSE(StatisticsRecorder::VLogInitializedForTesting());
+  logging::SetMinLogLevel(logging::LOG_VERBOSE);
+  EXPECT_TRUE(VLOG_IS_ON(1));
+  InitLogOnShutdown();
+  EXPECT_TRUE(StatisticsRecorder::VLogInitializedForTesting());
+}
+
+TEST_F(StatisticsRecorderLoggingVerboseOnStartupTest,
+       LogOnShutdownInitialized) {
+  EXPECT_TRUE(VLOG_IS_ON(1));
+  EXPECT_TRUE(StatisticsRecorder::VLogInitializedForTesting());
+}
+
 }  // namespace base