base/metrics/field_trial_unittest.cc - platform/external/chromium - Git at Google

 // Copyright (c) 2010 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.

 // Test of FieldTrial class

 #include "base/metrics/field_trial.h"

 #include "base/stringprintf.h"
 #include "testing/gtest/include/gtest/gtest.h"

 namespace base {

 class FieldTrialTest : public testing::Test {
  public:
   FieldTrialTest() : trial_list_() {
     Time now = Time::NowFromSystemTime();
     TimeDelta oneYear = TimeDelta::FromDays(365);
     Time::Exploded exploded;

     Time next_year_time = now + oneYear;
     next_year_time.LocalExplode(&exploded);
     next_year_ = exploded.year;

     Time last_year_time = now - oneYear;
     last_year_time.LocalExplode(&exploded);
     last_year_ = exploded.year;
   }

  protected:
   int next_year_;
   int last_year_;

  private:
   FieldTrialList trial_list_;
 };

 // Test registration, and also check that destructors are called for trials
 // (and that Purify doesn't catch us leaking).
 TEST_F(FieldTrialTest, Registration) {
   const char* name1 = "name 1 test";
   const char* name2 = "name 2 test";
   EXPECT_FALSE(FieldTrialList::Find(name1));
   EXPECT_FALSE(FieldTrialList::Find(name2));

   FieldTrial* trial1 =
       new FieldTrial(name1, 10, "default name 1 test", next_year_, 12, 31);
   EXPECT_EQ(FieldTrial::kNotFinalized, trial1->group_);
   EXPECT_EQ(name1, trial1->name());
   EXPECT_EQ("", trial1->group_name_internal());

   trial1->AppendGroup("", 7);

   EXPECT_EQ(trial1, FieldTrialList::Find(name1));
   EXPECT_FALSE(FieldTrialList::Find(name2));

   FieldTrial* trial2 =
       new FieldTrial(name2, 10, "default name 2 test", next_year_, 12, 31);
   EXPECT_EQ(FieldTrial::kNotFinalized, trial2->group_);
   EXPECT_EQ(name2, trial2->name());
   EXPECT_EQ("", trial2->group_name_internal());

   trial2->AppendGroup("a first group", 7);

   EXPECT_EQ(trial1, FieldTrialList::Find(name1));
   EXPECT_EQ(trial2, FieldTrialList::Find(name2));
   // Note: FieldTrialList should delete the objects at shutdown.
 }

 TEST_F(FieldTrialTest, AbsoluteProbabilities) {
   char always_true[] = " always true";
   char default_always_true[] = " default always true";
   char always_false[] = " always false";
   char default_always_false[] = " default always false";
   for (int i = 1; i < 250; ++i) {
     // Try lots of names, by changing the first character of the name.
     always_true[0] = i;
     default_always_true[0] = i;
     always_false[0] = i;
     default_always_false[0] = i;

     FieldTrial* trial_true =
         new FieldTrial(
             always_true, 10, default_always_true, next_year_, 12, 31);
     const std::string winner = "TheWinner";
     int winner_group = trial_true->AppendGroup(winner, 10);

     EXPECT_EQ(winner_group, trial_true->group());
     EXPECT_EQ(winner, trial_true->group_name());

     FieldTrial* trial_false =
         new FieldTrial(
             always_false, 10, default_always_false, next_year_, 12, 31);
     int loser_group = trial_false->AppendGroup("ALoser", 0);

     EXPECT_NE(loser_group, trial_false->group());
   }
 }

 TEST_F(FieldTrialTest, RemainingProbability) {
   // First create a test that hasn't had a winner yet.
   const std::string winner = "Winner";
   const std::string loser = "Loser";
   scoped_refptr<FieldTrial> trial;
   int counter = 0;
   do {
     std::string name = StringPrintf("trial%d", ++counter);
     trial = new FieldTrial(name, 10, winner, next_year_, 12, 31);
     trial->AppendGroup(loser, 5);  // 50% chance of not being chosen.
     // If a group is not assigned, group_ will be kNotFinalized.
   } while (trial->group_ != FieldTrial::kNotFinalized);

   // And that 'default' group (winner) should always win.
   EXPECT_EQ(FieldTrial::kDefaultGroupNumber, trial->group());

   // And that winner should ALWAYS win.
   EXPECT_EQ(winner, trial->group_name());
 }

 TEST_F(FieldTrialTest, FiftyFiftyProbability) {
   // Check that even with small divisors, we have the proper probabilities, and
   // all outcomes are possible.  Since this is a 50-50 test, it should get both
   // outcomes in a few tries, but we'll try no more than 100 times (and be flaky
   // with probability around 1 in 2^99).
   bool first_winner = false;
   bool second_winner = false;
   int counter = 0;
   do {
     std::string name = base::StringPrintf("FiftyFifty%d", ++counter);
     std::string default_group_name = base::StringPrintf("Default FiftyFifty%d",
                                                         ++counter);
     scoped_refptr<FieldTrial> trial(
         new FieldTrial(name, 2, default_group_name, next_year_, 12, 31));
     trial->AppendGroup("first", 1);  // 50% chance of being chosen.
     // If group_ is kNotFinalized, then a group assignement hasn't been done.
     if (trial->group_ != FieldTrial::kNotFinalized) {
       first_winner = true;
       continue;
     }
     trial->AppendGroup("second", 1);  // Always chosen at this point.
     EXPECT_NE(FieldTrial::kNotFinalized, trial->group());
     second_winner = true;
   } while ((!second_winner || !first_winner) && counter < 100);
   EXPECT_TRUE(second_winner);
   EXPECT_TRUE(first_winner);
 }

 TEST_F(FieldTrialTest, MiddleProbabilities) {
   char name[] = " same name";
   char default_group_name[] = " default same name";
   bool false_event_seen = false;
   bool true_event_seen = false;
   for (int i = 1; i < 250; ++i) {
     name[0] = i;
     default_group_name[0] = i;
     FieldTrial* trial =
         new FieldTrial(name, 10, default_group_name, next_year_, 12, 31);
     int might_win = trial->AppendGroup("MightWin", 5);

     if (trial->group() == might_win) {
       true_event_seen = true;
     } else {
       false_event_seen = true;
     }
     if (false_event_seen && true_event_seen)
       return;  // Successful test!!!
   }
   // Very surprising to get here. Probability should be around 1 in 2 ** 250.
   // One of the following will fail.
   EXPECT_TRUE(false_event_seen);
   EXPECT_TRUE(true_event_seen);
 }

 TEST_F(FieldTrialTest, OneWinner) {
   char name[] = "Some name";
   char default_group_name[] = "Default some name";
   int group_count(10);

   FieldTrial* trial =
       new FieldTrial(
           name, group_count, default_group_name, next_year_, 12, 31);
   int winner_index(-2);
   std::string winner_name;

   for (int i = 1; i <= group_count; ++i) {
     int might_win = trial->AppendGroup("", 1);

     // Because we keep appending groups, we want to see if the last group that
     // was added has been assigned or not.
     if (trial->group_ == might_win) {
       EXPECT_EQ(-2, winner_index);
       winner_index = might_win;
       StringAppendF(&winner_name, "%d", might_win);
       EXPECT_EQ(winner_name, trial->group_name());
     }
   }
   EXPECT_GE(winner_index, 0);
   EXPECT_EQ(trial->group(), winner_index);
   EXPECT_EQ(trial->group_name(), winner_name);
 }

 TEST_F(FieldTrialTest, DisableProbability) {
   const std::string default_group_name = "Default group";
   const std::string loser = "Loser";
   const std::string name = "Trial";

   // Create a field trail that has expired.
   scoped_refptr<FieldTrial> trial;
   trial = new FieldTrial(
       name, 1000000000, default_group_name, last_year_, 1, 1);
   trial->AppendGroup(loser, 999999999);  // 99.9999999% chance of being chosen.

   // Because trial has expired, we should always be in the default group.
   EXPECT_EQ(FieldTrial::kDefaultGroupNumber, trial->group());

   // And that default_group_name should ALWAYS win.
   EXPECT_EQ(default_group_name, trial->group_name());
 }

 TEST_F(FieldTrialTest, Save) {
   std::string save_string;

   FieldTrial* trial =
       new FieldTrial(
           "Some name", 10, "Default some name", next_year_, 12, 31);
   // There is no winner yet, so no textual group name is associated with trial.
   EXPECT_EQ("", trial->group_name_internal());
   FieldTrialList::StatesToString(&save_string);
   EXPECT_EQ("Some name/Default some name/", save_string);
   save_string.clear();

   // Create a winning group.
   trial->AppendGroup("Winner", 10);
   FieldTrialList::StatesToString(&save_string);
   EXPECT_EQ("Some name/Winner/", save_string);
   save_string.clear();

   // Create a second trial and winning group.
   FieldTrial* trial2 =
       new FieldTrial("xxx", 10, "Default xxx", next_year_, 12, 31);
   trial2->AppendGroup("yyyy", 10);

   FieldTrialList::StatesToString(&save_string);
   // We assume names are alphabetized... though this is not critical.
   EXPECT_EQ("Some name/Winner/xxx/yyyy/", save_string);
 }

 TEST_F(FieldTrialTest, Restore) {
   EXPECT_TRUE(FieldTrialList::Find("Some_name") == NULL);
   EXPECT_TRUE(FieldTrialList::Find("xxx") == NULL);

   FieldTrialList::CreateTrialsInChildProcess("Some_name/Winner/xxx/yyyy/");

   FieldTrial* trial = FieldTrialList::Find("Some_name");
   ASSERT_NE(static_cast<FieldTrial*>(NULL), trial);
   EXPECT_EQ("Winner", trial->group_name());
   EXPECT_EQ("Some_name", trial->name());

   trial = FieldTrialList::Find("xxx");
   ASSERT_NE(static_cast<FieldTrial*>(NULL), trial);
   EXPECT_EQ("yyyy", trial->group_name());
   EXPECT_EQ("xxx", trial->name());
 }

 TEST_F(FieldTrialTest, BogusRestore) {
   EXPECT_FALSE(FieldTrialList::CreateTrialsInChildProcess("MissingSlash"));
   EXPECT_FALSE(FieldTrialList::CreateTrialsInChildProcess("MissingGroupName/"));
   EXPECT_FALSE(
       FieldTrialList::CreateTrialsInChildProcess("MissingFinalSlash/gname"));
   EXPECT_FALSE(
       FieldTrialList::CreateTrialsInChildProcess("/noname, only group/"));
 }

 TEST_F(FieldTrialTest, DuplicateRestore) {
   FieldTrial* trial =
       new FieldTrial(
           "Some name", 10, "Default some name", next_year_, 12, 31);
   trial->AppendGroup("Winner", 10);
   std::string save_string;
   FieldTrialList::StatesToString(&save_string);
   EXPECT_EQ("Some name/Winner/", save_string);

   // It is OK if we redundantly specify a winner.
   EXPECT_TRUE(FieldTrialList::CreateTrialsInChildProcess(save_string));

   // But it is an error to try to change to a different winner.
   EXPECT_FALSE(FieldTrialList::CreateTrialsInChildProcess("Some name/Loser/"));
 }

 TEST_F(FieldTrialTest, MakeName) {
   FieldTrial* trial =
       new FieldTrial("Field Trial", 10, "Winner", next_year_, 12, 31);
   trial->group();
   EXPECT_EQ("Histogram_Winner",
             FieldTrial::MakeName("Histogram", "Field Trial"));
 }

 }  // namespace base
	// Copyright (c) 2010 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.

	// Test of FieldTrial class

	#include "base/metrics/field_trial.h"

	#include "base/stringprintf.h"
	#include "testing/gtest/include/gtest/gtest.h"

	namespace base {

	class FieldTrialTest : public testing::Test {
	public:
	FieldTrialTest() : trial_list_() {
	Time now = Time::NowFromSystemTime();
	TimeDelta oneYear = TimeDelta::FromDays(365);
	Time::Exploded exploded;

	Time next_year_time = now + oneYear;
	next_year_time.LocalExplode(&exploded);
	next_year_ = exploded.year;

	Time last_year_time = now - oneYear;
	last_year_time.LocalExplode(&exploded);
	last_year_ = exploded.year;
	}

	protected:
	int next_year_;
	int last_year_;

	private:
	FieldTrialList trial_list_;
	};

	// Test registration, and also check that destructors are called for trials
	// (and that Purify doesn't catch us leaking).
	TEST_F(FieldTrialTest, Registration) {
	const char* name1 = "name 1 test";
	const char* name2 = "name 2 test";
	EXPECT_FALSE(FieldTrialList::Find(name1));
	EXPECT_FALSE(FieldTrialList::Find(name2));

	FieldTrial* trial1 =
	new FieldTrial(name1, 10, "default name 1 test", next_year_, 12, 31);
	EXPECT_EQ(FieldTrial::kNotFinalized, trial1->group_);
	EXPECT_EQ(name1, trial1->name());
	EXPECT_EQ("", trial1->group_name_internal());

	trial1->AppendGroup("", 7);

	EXPECT_EQ(trial1, FieldTrialList::Find(name1));
	EXPECT_FALSE(FieldTrialList::Find(name2));

	FieldTrial* trial2 =
	new FieldTrial(name2, 10, "default name 2 test", next_year_, 12, 31);
	EXPECT_EQ(FieldTrial::kNotFinalized, trial2->group_);
	EXPECT_EQ(name2, trial2->name());
	EXPECT_EQ("", trial2->group_name_internal());

	trial2->AppendGroup("a first group", 7);

	EXPECT_EQ(trial1, FieldTrialList::Find(name1));
	EXPECT_EQ(trial2, FieldTrialList::Find(name2));
	// Note: FieldTrialList should delete the objects at shutdown.
	}

	TEST_F(FieldTrialTest, AbsoluteProbabilities) {
	char always_true[] = " always true";
	char default_always_true[] = " default always true";
	char always_false[] = " always false";
	char default_always_false[] = " default always false";
	for (int i = 1; i < 250; ++i) {
	// Try lots of names, by changing the first character of the name.
	always_true[0] = i;
	default_always_true[0] = i;
	always_false[0] = i;
	default_always_false[0] = i;

	FieldTrial* trial_true =
	new FieldTrial(
	always_true, 10, default_always_true, next_year_, 12, 31);
	const std::string winner = "TheWinner";
	int winner_group = trial_true->AppendGroup(winner, 10);

	EXPECT_EQ(winner_group, trial_true->group());
	EXPECT_EQ(winner, trial_true->group_name());

	FieldTrial* trial_false =
	new FieldTrial(
	always_false, 10, default_always_false, next_year_, 12, 31);
	int loser_group = trial_false->AppendGroup("ALoser", 0);

	EXPECT_NE(loser_group, trial_false->group());
	}
	}

	TEST_F(FieldTrialTest, RemainingProbability) {
	// First create a test that hasn't had a winner yet.
	const std::string winner = "Winner";
	const std::string loser = "Loser";
	scoped_refptr<FieldTrial> trial;
	int counter = 0;
	do {
	std::string name = StringPrintf("trial%d", ++counter);
	trial = new FieldTrial(name, 10, winner, next_year_, 12, 31);
	trial->AppendGroup(loser, 5); // 50% chance of not being chosen.
	// If a group is not assigned, group_ will be kNotFinalized.
	} while (trial->group_ != FieldTrial::kNotFinalized);

	// And that 'default' group (winner) should always win.
	EXPECT_EQ(FieldTrial::kDefaultGroupNumber, trial->group());

	// And that winner should ALWAYS win.
	EXPECT_EQ(winner, trial->group_name());
	}

	TEST_F(FieldTrialTest, FiftyFiftyProbability) {
	// Check that even with small divisors, we have the proper probabilities, and
	// all outcomes are possible. Since this is a 50-50 test, it should get both
	// outcomes in a few tries, but we'll try no more than 100 times (and be flaky
	// with probability around 1 in 2^99).
	bool first_winner = false;
	bool second_winner = false;
	int counter = 0;
	do {
	std::string name = base::StringPrintf("FiftyFifty%d", ++counter);
	std::string default_group_name = base::StringPrintf("Default FiftyFifty%d",
	++counter);
	scoped_refptr<FieldTrial> trial(
	new FieldTrial(name, 2, default_group_name, next_year_, 12, 31));
	trial->AppendGroup("first", 1); // 50% chance of being chosen.
	// If group_ is kNotFinalized, then a group assignement hasn't been done.
	if (trial->group_ != FieldTrial::kNotFinalized) {
	first_winner = true;
	continue;
	}
	trial->AppendGroup("second", 1); // Always chosen at this point.
	EXPECT_NE(FieldTrial::kNotFinalized, trial->group());
	second_winner = true;
	} while ((!second_winner \|\| !first_winner) && counter < 100);
	EXPECT_TRUE(second_winner);
	EXPECT_TRUE(first_winner);
	}

	TEST_F(FieldTrialTest, MiddleProbabilities) {
	char name[] = " same name";
	char default_group_name[] = " default same name";
	bool false_event_seen = false;
	bool true_event_seen = false;
	for (int i = 1; i < 250; ++i) {
	name[0] = i;
	default_group_name[0] = i;
	FieldTrial* trial =
	new FieldTrial(name, 10, default_group_name, next_year_, 12, 31);
	int might_win = trial->AppendGroup("MightWin", 5);

	if (trial->group() == might_win) {
	true_event_seen = true;
	} else {
	false_event_seen = true;
	}
	if (false_event_seen && true_event_seen)
	return; // Successful test!!!
	}
	// Very surprising to get here. Probability should be around 1 in 2 ** 250.
	// One of the following will fail.
	EXPECT_TRUE(false_event_seen);
	EXPECT_TRUE(true_event_seen);
	}

	TEST_F(FieldTrialTest, OneWinner) {
	char name[] = "Some name";
	char default_group_name[] = "Default some name";
	int group_count(10);

	FieldTrial* trial =
	new FieldTrial(
	name, group_count, default_group_name, next_year_, 12, 31);
	int winner_index(-2);
	std::string winner_name;

	for (int i = 1; i <= group_count; ++i) {
	int might_win = trial->AppendGroup("", 1);

	// Because we keep appending groups, we want to see if the last group that
	// was added has been assigned or not.
	if (trial->group_ == might_win) {
	EXPECT_EQ(-2, winner_index);
	winner_index = might_win;
	StringAppendF(&winner_name, "%d", might_win);
	EXPECT_EQ(winner_name, trial->group_name());
	}
	}
	EXPECT_GE(winner_index, 0);
	EXPECT_EQ(trial->group(), winner_index);
	EXPECT_EQ(trial->group_name(), winner_name);
	}

	TEST_F(FieldTrialTest, DisableProbability) {
	const std::string default_group_name = "Default group";
	const std::string loser = "Loser";
	const std::string name = "Trial";

	// Create a field trail that has expired.
	scoped_refptr<FieldTrial> trial;
	trial = new FieldTrial(
	name, 1000000000, default_group_name, last_year_, 1, 1);
	trial->AppendGroup(loser, 999999999); // 99.9999999% chance of being chosen.

	// Because trial has expired, we should always be in the default group.
	EXPECT_EQ(FieldTrial::kDefaultGroupNumber, trial->group());

	// And that default_group_name should ALWAYS win.
	EXPECT_EQ(default_group_name, trial->group_name());
	}

	TEST_F(FieldTrialTest, Save) {
	std::string save_string;

	FieldTrial* trial =
	new FieldTrial(
	"Some name", 10, "Default some name", next_year_, 12, 31);
	// There is no winner yet, so no textual group name is associated with trial.
	EXPECT_EQ("", trial->group_name_internal());
	FieldTrialList::StatesToString(&save_string);
	EXPECT_EQ("Some name/Default some name/", save_string);
	save_string.clear();

	// Create a winning group.
	trial->AppendGroup("Winner", 10);
	FieldTrialList::StatesToString(&save_string);
	EXPECT_EQ("Some name/Winner/", save_string);
	save_string.clear();

	// Create a second trial and winning group.
	FieldTrial* trial2 =
	new FieldTrial("xxx", 10, "Default xxx", next_year_, 12, 31);
	trial2->AppendGroup("yyyy", 10);

	FieldTrialList::StatesToString(&save_string);
	// We assume names are alphabetized... though this is not critical.
	EXPECT_EQ("Some name/Winner/xxx/yyyy/", save_string);
	}

	TEST_F(FieldTrialTest, Restore) {
	EXPECT_TRUE(FieldTrialList::Find("Some_name") == NULL);
	EXPECT_TRUE(FieldTrialList::Find("xxx") == NULL);

	FieldTrialList::CreateTrialsInChildProcess("Some_name/Winner/xxx/yyyy/");

	FieldTrial* trial = FieldTrialList::Find("Some_name");
	ASSERT_NE(static_cast<FieldTrial*>(NULL), trial);
	EXPECT_EQ("Winner", trial->group_name());
	EXPECT_EQ("Some_name", trial->name());

	trial = FieldTrialList::Find("xxx");
	ASSERT_NE(static_cast<FieldTrial*>(NULL), trial);
	EXPECT_EQ("yyyy", trial->group_name());
	EXPECT_EQ("xxx", trial->name());
	}

	TEST_F(FieldTrialTest, BogusRestore) {
	EXPECT_FALSE(FieldTrialList::CreateTrialsInChildProcess("MissingSlash"));
	EXPECT_FALSE(FieldTrialList::CreateTrialsInChildProcess("MissingGroupName/"));
	EXPECT_FALSE(
	FieldTrialList::CreateTrialsInChildProcess("MissingFinalSlash/gname"));
	EXPECT_FALSE(
	FieldTrialList::CreateTrialsInChildProcess("/noname, only group/"));
	}

	TEST_F(FieldTrialTest, DuplicateRestore) {
	FieldTrial* trial =
	new FieldTrial(
	"Some name", 10, "Default some name", next_year_, 12, 31);
	trial->AppendGroup("Winner", 10);
	std::string save_string;
	FieldTrialList::StatesToString(&save_string);
	EXPECT_EQ("Some name/Winner/", save_string);

	// It is OK if we redundantly specify a winner.
	EXPECT_TRUE(FieldTrialList::CreateTrialsInChildProcess(save_string));

	// But it is an error to try to change to a different winner.
	EXPECT_FALSE(FieldTrialList::CreateTrialsInChildProcess("Some name/Loser/"));
	}

	TEST_F(FieldTrialTest, MakeName) {
	FieldTrial* trial =
	new FieldTrial("Field Trial", 10, "Winner", next_year_, 12, 31);
	trial->group();
	EXPECT_EQ("Histogram_Winner",
	FieldTrial::MakeName("Histogram", "Field Trial"));
	}

	} // namespace base