time/time_unittest.cc

// Copyright 2012 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/time/time.h"

#include <stdint.h>
#include <time.h>

#include <limits>
#include <optional>
#include <string>

#include "base/build_time.h"
#include "base/check_op.h"
#include "base/compiler_specific.h"
#include "base/environment.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/to_string.h"
#include "base/test/gtest_util.h"
#include "base/threading/platform_thread.h"
#include "base/time/time_override.h"
#include "build/build_config.h"
#include "testing/gmock/include/gmock/gmock.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "third_party/icu/source/common/unicode/utypes.h"
#include "third_party/icu/source/i18n/unicode/timezone.h"

#if BUILDFLAG(IS_ANDROID)
#include "base/android/jni_android.h"
#elif BUILDFLAG(IS_FUCHSIA) || BUILDFLAG(IS_CHROMEOS)
#include "base/test/icu_test_util.h"
#elif BUILDFLAG(IS_WIN)
#include <windows.h>
#endif

namespace base {

namespace {

#if BUILDFLAG(IS_FUCHSIA)
// Hawaii does not observe daylight saving time, which is useful for having a
// constant offset when faking the time zone.
const char kHonoluluTimeZoneId[] = "Pacific/Honolulu";
const int kHonoluluOffsetHours = -10;
const int kHonoluluOffsetSeconds = kHonoluluOffsetHours * 60 * 60;
#endif

#if BUILDFLAG(IS_FUCHSIA) || BUILDFLAG(IS_CHROMEOS)

const char kThaiLocale[] = "th-TH";
const char kBangkokTimeZoneId[] = "Asia/Bangkok";

// Returns the total offset (including Daylight Saving Time) of the timezone
// with |timezone_id| at |time|, or std::nullopt in case of failure.
std::optional<base::TimeDelta> GetTimeZoneOffsetAtTime(const char* timezone_id,
                                                       Time time) {
  std::unique_ptr<icu::TimeZone> tz(icu::TimeZone::createTimeZone(timezone_id));
  if (*tz == icu::TimeZone::getUnknown()) {
    return {};
  }
  int32_t raw_offset = 0;
  int32_t dst_offset = 0;
  UErrorCode ec = U_ZERO_ERROR;
  tz->getOffset(time.InSecondsFSinceUnixEpoch(), false, raw_offset, dst_offset,
                ec);
  if (!U_SUCCESS(ec)) {
    return {};
  }
  return base::Milliseconds(raw_offset   dst_offset);
}

TimeDelta TimePassedAfterMidnight(const Time::Exploded& time) {
  return base::Hours(time.hour)   base::Minutes(time.minute)  
         base::Seconds(time.second)   base::Milliseconds(time.millisecond);
}

// Timezone environment variable

class ScopedLibcTZ {
 public:
  explicit ScopedLibcTZ(const std::string& timezone) {
    auto env = base::Environment::Create();
    std::string old_timezone_value;
    if (env->GetVar(kTZ, &old_timezone_value)) {
      old_timezone_ = old_timezone_value;
    }
    if (!env->SetVar(kTZ, timezone)) {
      success_ = false;
    }
    tzset();
  }

  ~ScopedLibcTZ() {
    auto env = base::Environment::Create();
    if (old_timezone_.has_value()) {
      CHECK(env->SetVar(kTZ, old_timezone_.value()));
    } else {
      CHECK(env->UnSetVar(kTZ));
    }
  }

  ScopedLibcTZ(const ScopedLibcTZ& other) = delete;
  ScopedLibcTZ& operator=(const ScopedLibcTZ& other) = delete;

  bool is_success() const { return success_; }

 private:
  static constexpr char kTZ[] = "TZ";

  bool success_ = true;
  std::optional<std::string> old_timezone_;
};

constexpr char ScopedLibcTZ::kTZ[];

#endif  //  BUILDFLAG(IS_FUCHSIA) || BUILDFLAG(IS_CHROMEOS)

TEST(TimeTestOutOfBounds, FromExplodedOutOfBoundsTime) {
  // FromUTCExploded must set time to Time(0) and failure, if the day is set to
  // 31 on a 28-30 day month. Test |exploded| returns Time(0) on 31st of
  // February and 31st of April. New implementation handles this.

  const struct DateTestData {
    Time::Exploded explode;
    bool is_valid;
  } kDateTestData[] = {
      // 31st of February
      {{2016, 2, 0, 31, 12, 30, 0, 0}, true},
      // 31st of April
      {{2016, 4, 0, 31, 8, 43, 0, 0}, true},
      // Negative month
      {{2016, -5, 0, 2, 4, 10, 0, 0}, false},
      // Negative date of month
      {{2016, 6, 0, -15, 2, 50, 0, 0}, false},
      // Negative hours
      {{2016, 7, 0, 10, -11, 29, 0, 0}, false},
      // Negative minutes
      {{2016, 3, 0, 14, 10, -29, 0, 0}, false},
      // Negative seconds
      {{2016, 10, 0, 25, 7, 47, -30, 0}, false},
      // Negative milliseconds
      {{2016, 10, 0, 25, 7, 47, 20, -500}, false},
      // Hours are too large
      {{2016, 7, 0, 10, 26, 29, 0, 0}, false},
      // Minutes are too large
      {{2016, 3, 0, 14, 10, 78, 0, 0}, false},
      // Seconds are too large
      {{2016, 10, 0, 25, 7, 47, 234, 0}, false},
      // Milliseconds are too large
      {{2016, 10, 0, 25, 6, 31, 23, 1643}, false},
      // Test overflow. Time is valid, but overflow case
      // results in Time(0).
      {{9840633, 1, 0, 1, 1, 1, 0, 0}, true},
      // Underflow will fail as well.
      {{-9840633, 1, 0, 1, 1, 1, 0, 0}, true},
      // Test integer overflow and underflow cases for the values themselves.
      {{std::numeric_limits<int>::min(), 1, 0, 1, 1, 1, 0, 0}, true},
      {{std::numeric_limits<int>::max(), 1, 0, 1, 1, 1, 0, 0}, true},
      {{2016, std::numeric_limits<int>::min(), 0, 1, 1, 1, 0, 0}, false},
      {{2016, std::numeric_limits<int>::max(), 0, 1, 1, 1, 0, 0}, false},
  };

  for (const auto& test : kDateTestData) {
    EXPECT_EQ(test.explode.HasValidValues(), test.is_valid);

    base::Time result;
    EXPECT_FALSE(base::Time::FromUTCExploded(test.explode, &result));
    EXPECT_TRUE(result.is_null());
    EXPECT_FALSE(base::Time::FromLocalExploded(test.explode, &result));
    EXPECT_TRUE(result.is_null());
  }
}

// Specialized test fixture allowing time strings without timezones to be
// tested by comparing them to a known time in the local zone.
// See also pr_time_unittests.cc
class TimeTest : public testing::Test {
 protected:
#if BUILDFLAG(IS_FUCHSIA)
  // POSIX local time functions always use UTC on Fuchsia. As this is not very
  // interesting for any "local" tests, set a different default ICU timezone for
  // the test. This only affects code that uses ICU, such as Exploded time.
  // Chicago is a non-Pacific time zone known to observe daylight saving time.
  TimeTest() : chicago_time_("America/Chicago") {}
  test::ScopedRestoreDefaultTimezone chicago_time_;
#endif

  void SetUp() override {
    // Use mktime to get a time_t, and turn it into a PRTime by converting
    // seconds to microseconds.  Use 15th Oct 2007 12:45:00 local.  This
    // must be a time guaranteed to be outside of a DST fallback hour in
    // any timezone.
    struct tm local_comparison_tm = {
      0,            // second
      45,           // minute
      12,           // hour
      15,           // day of month
      10 - 1,       // month
      2007 - 1900,  // year
      0,            // day of week (ignored, output only)
      0,            // day of year (ignored, output only)
      -1            // DST in effect, -1 tells mktime to figure it out
    };

    time_t converted_time = mktime(&local_comparison_tm);
    ASSERT_GT(converted_time, 0);
    comparison_time_local_ = Time::FromTimeT(converted_time);

    // time_t representation of 15th Oct 2007 12:45:00 PDT
    comparison_time_pdt_ = Time::FromTimeT(1192477500);
  }

  Time comparison_time_local_;
  Time comparison_time_pdt_;
};

// Test conversion to/from TimeDeltas elapsed since the Windows epoch.
// Conversions should be idempotent and non-lossy.
TEST_F(TimeTest, DeltaSinceWindowsEpoch) {
  constexpr TimeDelta delta = Microseconds(123);
  EXPECT_EQ(delta,
            Time::FromDeltaSinceWindowsEpoch(delta).ToDeltaSinceWindowsEpoch());

  const Time now = Time::Now();
  const Time actual =
      Time::FromDeltaSinceWindowsEpoch(now.ToDeltaSinceWindowsEpoch());
  EXPECT_EQ(now, actual);

  // Null times should remain null after a round-trip conversion. This is an
  // important invariant for the common use case of serialization  
  // deserialization.
  const Time should_be_null =
      Time::FromDeltaSinceWindowsEpoch(Time().ToDeltaSinceWindowsEpoch());
  EXPECT_TRUE(should_be_null.is_null());

  {
    constexpr Time constexpr_time =
        Time::FromDeltaSinceWindowsEpoch(Microseconds(123));
    constexpr TimeDelta constexpr_delta =
        constexpr_time.ToDeltaSinceWindowsEpoch();
    static_assert(constexpr_delta == delta);
  }
}

// Test conversion to/from time_t.
TEST_F(TimeTest, TimeT) {
  EXPECT_EQ(10, Time().FromTimeT(10).ToTimeT());
  EXPECT_EQ(10.0, Time().FromTimeT(10).InSecondsFSinceUnixEpoch());

  // Conversions of 0 should stay 0.
  EXPECT_EQ(0, Time().ToTimeT());
  EXPECT_EQ(0, Time::FromTimeT(0).ToInternalValue());
}

// Test conversions to/from time_t and exploding/unexploding (utc time).
TEST_F(TimeTest, UTCTimeT) {
  // C library time and exploded time.
  time_t now_t_1 = time(nullptr);
  struct tm tms;
#if BUILDFLAG(IS_WIN)
  gmtime_s(&tms, &now_t_1);
#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
  gmtime_r(&now_t_1, &tms);
#endif

  // Convert to ours.
  Time our_time_1 = Time::FromTimeT(now_t_1);
  Time::Exploded exploded;
  our_time_1.UTCExplode(&exploded);

  // This will test both our exploding and our time_t -> Time conversion.
  EXPECT_EQ(tms.tm_year   1900, exploded.year);
  EXPECT_EQ(tms.tm_mon   1, exploded.month);
  EXPECT_EQ(tms.tm_mday, exploded.day_of_month);
  EXPECT_EQ(tms.tm_hour, exploded.hour);
  EXPECT_EQ(tms.tm_min, exploded.minute);
  EXPECT_EQ(tms.tm_sec, exploded.second);

  // Convert exploded back to the time struct.
  Time our_time_2;
  EXPECT_TRUE(Time::FromUTCExploded(exploded, &our_time_2));
  EXPECT_TRUE(our_time_1 == our_time_2);

  time_t now_t_2 = our_time_2.ToTimeT();
  EXPECT_EQ(now_t_1, now_t_2);
}

// Test conversions to/from time_t and exploding/unexploding (local time).
TEST_F(TimeTest, LocalTimeT) {
  // C library time and exploded time.
  time_t now_t_1 = time(nullptr);
  struct tm tms;

#if BUILDFLAG(IS_WIN)
  localtime_s(&tms, &now_t_1);
#elif BUILDFLAG(IS_POSIX)
  localtime_r(&now_t_1, &tms);
#elif BUILDFLAG(IS_FUCHSIA)
  // POSIX local time functions always use UTC on Fuchsia, so set a known time
  // zone and manually obtain the local |tms| values by using an adjusted input.
  test::ScopedRestoreDefaultTimezone honolulu_time(kHonoluluTimeZoneId);
  time_t adjusted_now_t_1 = now_t_1   kHonoluluOffsetSeconds;
  localtime_r(&adjusted_now_t_1, &tms);
#endif

  // Convert to ours.
  Time our_time_1 = Time::FromTimeT(now_t_1);
  Time::Exploded exploded;
  our_time_1.LocalExplode(&exploded);

  // This will test both our exploding and our time_t -> Time conversion.
  EXPECT_EQ(tms.tm_year   1900, exploded.year);
  EXPECT_EQ(tms.tm_mon   1, exploded.month);
  EXPECT_EQ(tms.tm_mday, exploded.day_of_month);
  EXPECT_EQ(tms.tm_hour, exploded.hour);
  EXPECT_EQ(tms.tm_min, exploded.minute);
  EXPECT_EQ(tms.tm_sec, exploded.second);

  // Convert exploded back to the time struct.
  Time our_time_2;
  EXPECT_TRUE(Time::FromLocalExploded(exploded, &our_time_2));
  EXPECT_TRUE(our_time_1 == our_time_2);

  time_t now_t_2 = our_time_2.ToTimeT();
  EXPECT_EQ(now_t_1, now_t_2);
}

// Test conversions to/from javascript time.
TEST_F(TimeTest, JsTime) {
  Time epoch = Time::FromMillisecondsSinceUnixEpoch(0.0);
  EXPECT_EQ(epoch, Time::UnixEpoch());
  Time t = Time::FromMillisecondsSinceUnixEpoch(700000.3);
  EXPECT_EQ(700.0003, t.InSecondsFSinceUnixEpoch());
  t = Time::FromSecondsSinceUnixEpoch(800.73);
  EXPECT_EQ(800730.0, t.InMillisecondsFSinceUnixEpoch());

  // 1601-01-01 isn't round-trip with InMillisecondsFSinceUnixEpoch().
  const double kWindowsEpoch = -11644473600000.0;
  Time time = Time::FromMillisecondsSinceUnixEpoch(kWindowsEpoch);
  EXPECT_TRUE(time.is_null());
  EXPECT_NE(kWindowsEpoch, time.InMillisecondsFSinceUnixEpoch());
  EXPECT_EQ(kWindowsEpoch, time.InMillisecondsFSinceUnixEpochIgnoringNull());
}

#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
TEST_F(TimeTest, FromTimeVal) {
  Time now = Time::Now();
  Time also_now = Time::FromTimeVal(now.ToTimeVal());
  EXPECT_EQ(now, also_now);
}
#endif  // BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)

TEST_F(TimeTest, FromExplodedWithMilliseconds) {
  // Some platform implementations of FromExploded are liable to drop
  // milliseconds if we aren't careful.
  Time now = Time::NowFromSystemTime();
  Time::Exploded exploded1 = {0};
  now.UTCExplode(&exploded1);
  exploded1.millisecond = 500;
  Time time;
  EXPECT_TRUE(Time::FromUTCExploded(exploded1, &time));
  Time::Exploded exploded2 = {0};
  time.UTCExplode(&exploded2);
  EXPECT_EQ(exploded1.millisecond, exploded2.millisecond);
}

TEST_F(TimeTest, ZeroIsSymmetric) {
  Time zero_time(Time::FromTimeT(0));
  EXPECT_EQ(0, zero_time.ToTimeT());

  EXPECT_EQ(0.0, zero_time.InSecondsFSinceUnixEpoch());
}

// Note that this test does not check whether the implementation correctly
// accounts for the local time zone.
TEST_F(TimeTest, LocalExplode) {
  Time a = Time::Now();
  Time::Exploded exploded;
  a.LocalExplode(&exploded);

  Time b;
  EXPECT_TRUE(Time::FromLocalExploded(exploded, &b));

  // The exploded structure doesn't have microseconds, and on Mac & Linux, the
  // internal OS conversion uses seconds, which will cause truncation. So we
  // can only make sure that the delta is within one second.
  EXPECT_LT(a - b, Seconds(1));
}

TEST_F(TimeTest, UTCExplode) {
  Time a = Time::Now();
  Time::Exploded exploded;
  a.UTCExplode(&exploded);

  Time b;
  EXPECT_TRUE(Time::FromUTCExploded(exploded, &b));

  // The exploded structure doesn't have microseconds, and on Mac & Linux, the
  // internal OS conversion uses seconds, which will cause truncation. So we
  // can only make sure that the delta is within one second.
  EXPECT_LT(a - b, Seconds(1));
}

TEST_F(TimeTest, UTCMidnight) {
  Time::Exploded exploded;
  Time::Now().UTCMidnight().UTCExplode(&exploded);
  EXPECT_EQ(0, exploded.hour);
  EXPECT_EQ(0, exploded.minute);
  EXPECT_EQ(0, exploded.second);
  EXPECT_EQ(0, exploded.millisecond);
}

// Note that this test does not check whether the implementation correctly
// accounts for the local time zone.
TEST_F(TimeTest, LocalMidnight) {
  Time::Exploded exploded;
  Time::Now().LocalMidnight().LocalExplode(&exploded);
  EXPECT_EQ(0, exploded.hour);
  EXPECT_EQ(0, exploded.minute);
  EXPECT_EQ(0, exploded.second);
  EXPECT_EQ(0, exploded.millisecond);
}

// These tests require the ability to fake the local time zone.
#if BUILDFLAG(IS_FUCHSIA)
TEST_F(TimeTest, LocalExplodeIsLocal) {
  // Set the default time zone to a zone with an offset different from UTC.
  test::ScopedRestoreDefaultTimezone honolulu_time(kHonoluluTimeZoneId);

  // The member contains useful values for this test, which uses it as UTC.
  Time comparison_time_utc(comparison_time_local_);

  Time::Exploded utc_exploded;
  comparison_time_utc.UTCExplode(&utc_exploded);

  Time::Exploded local_exploded;
  comparison_time_utc.LocalExplode(&local_exploded);

  // The year, month, and day are the same because the (negative) offset is
  // smaller than the hour in the test time. Similarly, there is no underflow
  // for hour.
  EXPECT_EQ(utc_exploded.year, local_exploded.year);
  EXPECT_EQ(utc_exploded.month, local_exploded.month);
  EXPECT_EQ(utc_exploded.day_of_week, local_exploded.day_of_week);
  EXPECT_EQ(utc_exploded.day_of_month, local_exploded.day_of_month);
  EXPECT_EQ(utc_exploded.hour   kHonoluluOffsetHours, local_exploded.hour);
  EXPECT_EQ(utc_exploded.minute, local_exploded.minute);
  EXPECT_EQ(utc_exploded.second, local_exploded.second);
  EXPECT_EQ(utc_exploded.millisecond, local_exploded.millisecond);

  Time time_from_local_exploded;
  EXPECT_TRUE(
      Time::FromLocalExploded(local_exploded, &time_from_local_exploded));

  EXPECT_EQ(comparison_time_utc, time_from_local_exploded);

  // Unexplode the local time using the non-local method.
  // The resulting time should be offset hours earlier.
  Time time_from_utc_exploded;
  EXPECT_TRUE(Time::FromUTCExploded(local_exploded, &time_from_utc_exploded));
  EXPECT_EQ(comparison_time_utc   Hours(kHonoluluOffsetHours),
            time_from_utc_exploded);
}

TEST_F(TimeTest, LocalMidnightIsLocal) {
  // Set the default time zone to a zone with an offset different from UTC.
  test::ScopedRestoreDefaultTimezone honolulu_time(kHonoluluTimeZoneId);

  // The member contains useful values for this test, which uses it as UTC.
  Time comparison_time_utc(comparison_time_local_);

  Time::Exploded utc_midnight_exploded;
  comparison_time_utc.UTCMidnight().UTCExplode(&utc_midnight_exploded);

  // Local midnight exploded in UTC will have an offset hour instead of 0.
  Time::Exploded local_midnight_utc_exploded;
  comparison_time_utc.LocalMidnight().UTCExplode(&local_midnight_utc_exploded);

  // The year, month, and day are the same because the (negative) offset is
  // smaller than the hour in the test time and thus both midnights round down
  // on the same day.
  EXPECT_EQ(utc_midnight_exploded.year, local_midnight_utc_exploded.year);
  EXPECT_EQ(utc_midnight_exploded.month, local_midnight_utc_exploded.month);
  EXPECT_EQ(utc_midnight_exploded.day_of_week,
            local_midnight_utc_exploded.day_of_week);
  EXPECT_EQ(utc_midnight_exploded.day_of_month,
            local_midnight_utc_exploded.day_of_month);
  EXPECT_EQ(0, utc_midnight_exploded.hour);
  EXPECT_EQ(0 - kHonoluluOffsetHours, local_midnight_utc_exploded.hour);
  EXPECT_EQ(0, local_midnight_utc_exploded.minute);
  EXPECT_EQ(0, local_midnight_utc_exploded.second);
  EXPECT_EQ(0, local_midnight_utc_exploded.millisecond);

  // Local midnight exploded in local time will have no offset.
  Time::Exploded local_midnight_exploded;
  comparison_time_utc.LocalMidnight().LocalExplode(&local_midnight_exploded);

  EXPECT_EQ(utc_midnight_exploded.year, local_midnight_exploded.year);
  EXPECT_EQ(utc_midnight_exploded.month, local_midnight_exploded.month);
  EXPECT_EQ(utc_midnight_exploded.day_of_week,
            local_midnight_exploded.day_of_week);
  EXPECT_EQ(utc_midnight_exploded.day_of_month,
            local_midnight_exploded.day_of_month);
  EXPECT_EQ(0, local_midnight_exploded.hour);
  EXPECT_EQ(0, local_midnight_exploded.minute);
  EXPECT_EQ(0, local_midnight_exploded.second);
  EXPECT_EQ(0, local_midnight_exploded.millisecond);
}
#endif  // BUILDFLAG(IS_FUCHSIA)

TEST_F(TimeTest, ParseTimeTest1) {
  time_t current_time = 0;
  time(&current_time);

  struct tm local_time = {};
  char time_buf[64] = {};
#if BUILDFLAG(IS_WIN)
  localtime_s(&local_time, &current_time);
  asctime_s(time_buf, std::size(time_buf), &local_time);
#elif BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
  localtime_r(&current_time, &local_time);
  asctime_r(&local_time, time_buf);
#endif

  Time parsed_time;
  EXPECT_TRUE(Time::FromString(time_buf, &parsed_time));
  EXPECT_EQ(current_time, parsed_time.ToTimeT());
}

TEST_F(TimeTest, DayOfWeekSunday) {
  Time time;
  EXPECT_TRUE(Time::FromString("Sun, 06 May 2012 12:00:00 GMT", &time));
  Time::Exploded exploded;
  time.UTCExplode(&exploded);
  EXPECT_EQ(0, exploded.day_of_week);
}

TEST_F(TimeTest, DayOfWeekWednesday) {
  Time time;
  EXPECT_TRUE(Time::FromString("Wed, 09 May 2012 12:00:00 GMT", &time));
  Time::Exploded exploded;
  time.UTCExplode(&exploded);
  EXPECT_EQ(3, exploded.day_of_week);
}

TEST_F(TimeTest, DayOfWeekSaturday) {
  Time time;
  EXPECT_TRUE(Time::FromString("Sat, 12 May 2012 12:00:00 GMT", &time));
  Time::Exploded exploded;
  time.UTCExplode(&exploded);
  EXPECT_EQ(6, exploded.day_of_week);
}

TEST_F(TimeTest, ParseTimeTest2) {
  Time parsed_time;
  EXPECT_TRUE(Time::FromString("Mon, 15 Oct 2007 19:45:00 GMT", &parsed_time));
  EXPECT_EQ(comparison_time_pdt_, parsed_time);
}

TEST_F(TimeTest, ParseTimeTest3) {
  Time parsed_time;
  EXPECT_TRUE(Time::FromString("15 Oct 07 12:45:00", &parsed_time));
  EXPECT_EQ(comparison_time_local_, parsed_time);
}

TEST_F(TimeTest, ParseTimeTest4) {
  Time parsed_time;
  EXPECT_TRUE(Time::FromString("15 Oct 07 19:45 GMT", &parsed_time));
  EXPECT_EQ(comparison_time_pdt_, parsed_time);
}

TEST_F(TimeTest, ParseTimeTest5) {
  Time parsed_time;
  EXPECT_TRUE(Time::FromString("Mon Oct 15 12:45 PDT 2007", &parsed_time));
  EXPECT_EQ(comparison_time_pdt_, parsed_time);
}

TEST_F(TimeTest, ParseTimeTest6) {
  Time parsed_time;
  EXPECT_TRUE(Time::FromString("Monday, Oct 15, 2007 12:45 PM", &parsed_time));
  EXPECT_EQ(comparison_time_local_, parsed_time);
}

TEST_F(TimeTest, ParseTimeTest7) {
  Time parsed_time;
  EXPECT_TRUE(Time::FromString("10/15/07 12:45:00 PM", &parsed_time));
  EXPECT_EQ(comparison_time_local_, parsed_time);
}

TEST_F(TimeTest, ParseTimeTest8) {
  Time parsed_time;
  EXPECT_TRUE(Time::FromString("15-OCT-2007 12:45pm", &parsed_time));
  EXPECT_EQ(comparison_time_local_, parsed_time);
}

TEST_F(TimeTest, ParseTimeTest9) {
  Time parsed_time;
  EXPECT_TRUE(Time::FromString("16 Oct 2007 4:45-JST (Tuesday)", &parsed_time));
  EXPECT_EQ(comparison_time_pdt_, parsed_time);
}

TEST_F(TimeTest, ParseTimeTest10) {
  Time parsed_time;
  EXPECT_TRUE(Time::FromString("15/10/07 12:45", &parsed_time));
  EXPECT_EQ(parsed_time, comparison_time_local_);
}

TEST_F(TimeTest, ParseTimeTest11) {
  Time parsed_time;
  EXPECT_TRUE(Time::FromString("2007-10-15 12:45:00", &parsed_time));
  EXPECT_EQ(parsed_time, comparison_time_local_);
}

// Test some of edge cases around epoch, etc.
TEST_F(TimeTest, ParseTimeTestEpoch0) {
  Time parsed_time;

  // time_t == epoch == 0
  EXPECT_TRUE(Time::FromString("Thu Jan 01 01:00:00  0100 1970",
                               &parsed_time));
  EXPECT_EQ(0, parsed_time.ToTimeT());
  EXPECT_TRUE(Time::FromString("Thu Jan 01 00:00:00 GMT 1970",
                               &parsed_time));
  EXPECT_EQ(0, parsed_time.ToTimeT());
}

TEST_F(TimeTest, ParseTimeTestEpoch1) {
  Time parsed_time;

  // time_t == 1 second after epoch == 1
  EXPECT_TRUE(Time::FromString("Thu Jan 01 01:00:01  0100 1970",
                               &parsed_time));
  EXPECT_EQ(1, parsed_time.ToTimeT());
  EXPECT_TRUE(Time::FromString("Thu Jan 01 00:00:01 GMT 1970",
                               &parsed_time));
  EXPECT_EQ(1, parsed_time.ToTimeT());
}

TEST_F(TimeTest, ParseTimeTestEpoch2) {
  Time parsed_time;

  // time_t == 2 seconds after epoch == 2
  EXPECT_TRUE(Time::FromString("Thu Jan 01 01:00:02  0100 1970",
                               &parsed_time));
  EXPECT_EQ(2, parsed_time.ToTimeT());
  EXPECT_TRUE(Time::FromString("Thu Jan 01 00:00:02 GMT 1970",
                               &parsed_time));
  EXPECT_EQ(2, parsed_time.ToTimeT());
}

TEST_F(TimeTest, ParseTimeTestEpochNeg1) {
  Time parsed_time;

  // time_t == 1 second before epoch == -1
  EXPECT_TRUE(Time::FromString("Thu Jan 01 00:59:59  0100 1970",
                               &parsed_time));
  EXPECT_EQ(-1, parsed_time.ToTimeT());
  EXPECT_TRUE(Time::FromString("Wed Dec 31 23:59:59 GMT 1969",
                               &parsed_time));
  EXPECT_EQ(-1, parsed_time.ToTimeT());
}

// If time_t is 32 bits, a date after year 2038 will overflow time_t and
// cause timegm() to return -1.  The parsed time should not be 1 second
// before epoch.
TEST_F(TimeTest, ParseTimeTestEpochNotNeg1) {
  Time parsed_time;

  EXPECT_TRUE(Time::FromString("Wed Dec 31 23:59:59 GMT 2100",
                               &parsed_time));
  EXPECT_NE(-1, parsed_time.ToTimeT());
}

TEST_F(TimeTest, ParseTimeTestEpochNeg2) {
  Time parsed_time;

  // time_t == 2 seconds before epoch == -2
  EXPECT_TRUE(Time::FromString("Thu Jan 01 00:59:58  0100 1970",
                               &parsed_time));
  EXPECT_EQ(-2, parsed_time.ToTimeT());
  EXPECT_TRUE(Time::FromString("Wed Dec 31 23:59:58 GMT 1969",
                               &parsed_time));
  EXPECT_EQ(-2, parsed_time.ToTimeT());
}

TEST_F(TimeTest, ParseTimeTestEpoch1960) {
  Time parsed_time;

  // time_t before Epoch, in 1960
  EXPECT_TRUE(Time::FromString("Wed Jun 29 19:40:01  0100 1960",
                               &parsed_time));
  EXPECT_EQ(-299999999, parsed_time.ToTimeT());
  EXPECT_TRUE(Time::FromString("Wed Jun 29 18:40:01 GMT 1960",
                               &parsed_time));
  EXPECT_EQ(-299999999, parsed_time.ToTimeT());
  EXPECT_TRUE(Time::FromString("Wed Jun 29 17:40:01 GMT 1960",
                               &parsed_time));
  EXPECT_EQ(-300003599, parsed_time.ToTimeT());
}

TEST_F(TimeTest, ParseTimeTestEmpty) {
  Time parsed_time;
  EXPECT_FALSE(Time::FromString("", &parsed_time));
}

TEST_F(TimeTest, ParseTimeTestInvalidString) {
  Time parsed_time;
  EXPECT_FALSE(Time::FromString("Monday morning 2000", &parsed_time));
}

TEST_F(TimeTest, ExplodeBeforeUnixEpoch) {
  static const int kUnixEpochYear = 1970;  // In case this changes (ha!).
  Time t;
  Time::Exploded exploded;

  t = Time::UnixEpoch() - Microseconds(1);
  t.UTCExplode(&exploded);
  EXPECT_TRUE(exploded.HasValidValues());
  // Should be 1969-12-31 23:59:59 999 milliseconds (and 999 microseconds).
  EXPECT_EQ(kUnixEpochYear - 1, exploded.year);
  EXPECT_EQ(12, exploded.month);
  EXPECT_EQ(31, exploded.day_of_month);
  EXPECT_EQ(23, exploded.hour);
  EXPECT_EQ(59, exploded.minute);
  EXPECT_EQ(59, exploded.second);
  EXPECT_EQ(999, exploded.millisecond);

  t = Time::UnixEpoch() - Microseconds(999);
  t.UTCExplode(&exploded);
  EXPECT_TRUE(exploded.HasValidValues());
  // Should be 1969-12-31 23:59:59 999 milliseconds (and 1 microsecond).
  EXPECT_EQ(kUnixEpochYear - 1, exploded.year);
  EXPECT_EQ(12, exploded.month);
  EXPECT_EQ(31, exploded.day_of_month);
  EXPECT_EQ(23, exploded.hour);
  EXPECT_EQ(59, exploded.minute);
  EXPECT_EQ(59, exploded.second);
  EXPECT_EQ(999, exploded.millisecond);

  t = Time::UnixEpoch() - Microseconds(1000);
  t.UTCExplode(&exploded);
  EXPECT_TRUE(exploded.HasValidValues());
  // Should be 1969-12-31 23:59:59 999 milliseconds.
  EXPECT_EQ(kUnixEpochYear - 1, exploded.year);
  EXPECT_EQ(12, exploded.month);
  EXPECT_EQ(31, exploded.day_of_month);
  EXPECT_EQ(23, exploded.hour);
  EXPECT_EQ(59, exploded.minute);
  EXPECT_EQ(59, exploded.second);
  EXPECT_EQ(999, exploded.millisecond);

  t = Time::UnixEpoch() - Microseconds(1001);
  t.UTCExplode(&exploded);
  EXPECT_TRUE(exploded.HasValidValues());
  // Should be 1969-12-31 23:59:59 998 milliseconds (and 999 microseconds).
  EXPECT_EQ(kUnixEpochYear - 1, exploded.year);
  EXPECT_EQ(12, exploded.month);
  EXPECT_EQ(31, exploded.day_of_month);
  EXPECT_EQ(23, exploded.hour);
  EXPECT_EQ(59, exploded.minute);
  EXPECT_EQ(59, exploded.second);
  EXPECT_EQ(998, exploded.millisecond);

  t = Time::UnixEpoch() - Milliseconds(1000);
  t.UTCExplode(&exploded);
  EXPECT_TRUE(exploded.HasValidValues());
  // Should be 1969-12-31 23:59:59.
  EXPECT_EQ(kUnixEpochYear - 1, exploded.year);
  EXPECT_EQ(12, exploded.month);
  EXPECT_EQ(31, exploded.day_of_month);
  EXPECT_EQ(23, exploded.hour);
  EXPECT_EQ(59, exploded.minute);
  EXPECT_EQ(59, exploded.second);
  EXPECT_EQ(0, exploded.millisecond);

  t = Time::UnixEpoch() - Milliseconds(1001);
  t.UTCExplode(&exploded);
  EXPECT_TRUE(exploded.HasValidValues());
  // Should be 1969-12-31 23:59:58 999 milliseconds.
  EXPECT_EQ(kUnixEpochYear - 1, exploded.year);
  EXPECT_EQ(12, exploded.month);
  EXPECT_EQ(31, exploded.day_of_month);
  EXPECT_EQ(23, exploded.hour);
  EXPECT_EQ(59, exploded.minute);
  EXPECT_EQ(58, exploded.second);
  EXPECT_EQ(999, exploded.millisecond);

  // Make sure we still handle at/after Unix epoch correctly.
  t = Time::UnixEpoch();
  t.UTCExplode(&exploded);
  EXPECT_TRUE(exploded.HasValidValues());
  // Should be 1970-12-31 00:00:00 0 milliseconds.
  EXPECT_EQ(kUnixEpochYear, exploded.year);
  EXPECT_EQ(1, exploded.month);
  EXPECT_EQ(1, exploded.day_of_month);
  EXPECT_EQ(0, exploded.hour);
  EXPECT_EQ(0, exploded.minute);
  EXPECT_EQ(0, exploded.second);
  EXPECT_EQ(0, exploded.millisecond);

  t = Time::UnixEpoch()   Microseconds(1);
  t.UTCExplode(&exploded);
  EXPECT_TRUE(exploded.HasValidValues());
  // Should be 1970-01-01 00:00:00 0 milliseconds (and 1 microsecond).
  EXPECT_EQ(kUnixEpochYear, exploded.year);
  EXPECT_EQ(1, exploded.month);
  EXPECT_EQ(1, exploded.day_of_month);
  EXPECT_EQ(0, exploded.hour);
  EXPECT_EQ(0, exploded.minute);
  EXPECT_EQ(0, exploded.second);
  EXPECT_EQ(0, exploded.millisecond);

  t = Time::UnixEpoch()   Microseconds(999);
  t.UTCExplode(&exploded);
  EXPECT_TRUE(exploded.HasValidValues());
  // Should be 1970-01-01 00:00:00 0 milliseconds (and 999 microseconds).
  EXPECT_EQ(kUnixEpochYear, exploded.year);
  EXPECT_EQ(1, exploded.month);
  EXPECT_EQ(1, exploded.day_of_month);
  EXPECT_EQ(0, exploded.hour);
  EXPECT_EQ(0, exploded.minute);
  EXPECT_EQ(0, exploded.second);
  EXPECT_EQ(0, exploded.millisecond);

  t = Time::UnixEpoch()   Microseconds(1000);
  t.UTCExplode(&exploded);
  EXPECT_TRUE(exploded.HasValidValues());
  // Should be 1970-01-01 00:00:00 1 millisecond.
  EXPECT_EQ(kUnixEpochYear, exploded.year);
  EXPECT_EQ(1, exploded.month);
  EXPECT_EQ(1, exploded.day_of_month);
  EXPECT_EQ(0, exploded.hour);
  EXPECT_EQ(0, exploded.minute);
  EXPECT_EQ(0, exploded.second);
  EXPECT_EQ(1, exploded.millisecond);

  t = Time::UnixEpoch()   Milliseconds(1000);
  t.UTCExplode(&exploded);
  EXPECT_TRUE(exploded.HasValidValues());
  // Should be 1970-01-01 00:00:01.
  EXPECT_EQ(kUnixEpochYear, exploded.year);
  EXPECT_EQ(1, exploded.month);
  EXPECT_EQ(1, exploded.day_of_month);
  EXPECT_EQ(0, exploded.hour);
  EXPECT_EQ(0, exploded.minute);
  EXPECT_EQ(1, exploded.second);
  EXPECT_EQ(0, exploded.millisecond);

  t = Time::UnixEpoch()   Milliseconds(1001);
  t.UTCExplode(&exploded);
  EXPECT_TRUE(exploded.HasValidValues());
  // Should be 1970-01-01 00:00:01 1 millisecond.
  EXPECT_EQ(kUnixEpochYear, exploded.year);
  EXPECT_EQ(1, exploded.month);
  EXPECT_EQ(1, exploded.day_of_month);
  EXPECT_EQ(0, exploded.hour);
  EXPECT_EQ(0, exploded.minute);
  EXPECT_EQ(1, exploded.second);
  EXPECT_EQ(1, exploded.millisecond);
}

TEST_F(TimeTest, Max) {
  constexpr Time kMax = Time::Max();
  static_assert(kMax.is_max());
  static_assert(kMax == Time::Max());
  EXPECT_GT(kMax, Time::Now());
  static_assert(kMax > Time());
  EXPECT_TRUE((Time::Now() - kMax).is_negative());
  EXPECT_TRUE((kMax - Time::Now()).is_positive());
}

TEST_F(TimeTest, MaxConversions) {
  constexpr Time kMax = Time::Max();
  static_assert(std::numeric_limits<int64_t>::max() == kMax.ToInternalValue(),
                "");

  Time t =
      Time::FromSecondsSinceUnixEpoch(std::numeric_limits<double>::infinity());
  EXPECT_TRUE(t.is_max());
  EXPECT_EQ(std::numeric_limits<double>::infinity(),
            t.InSecondsFSinceUnixEpoch());

  t = Time::FromMillisecondsSinceUnixEpoch(
      std::numeric_limits<double>::infinity());
  EXPECT_TRUE(t.is_max());
  EXPECT_EQ(std::numeric_limits<double>::infinity(),
            t.InMillisecondsFSinceUnixEpoch());

  t = Time::FromTimeT(std::numeric_limits<time_t>::max());
  EXPECT_TRUE(t.is_max());
  EXPECT_EQ(std::numeric_limits<time_t>::max(), t.ToTimeT());

#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
  struct timeval tval;
  tval.tv_sec = std::numeric_limits<time_t>::max();
  tval.tv_usec = static_cast<suseconds_t>(Time::kMicrosecondsPerSecond) - 1;
  t = Time::FromTimeVal(tval);
  EXPECT_TRUE(t.is_max());
  tval = t.ToTimeVal();
  EXPECT_EQ(std::numeric_limits<time_t>::max(), tval.tv_sec);
  EXPECT_EQ(static_cast<suseconds_t>(Time::kMicrosecondsPerSecond) - 1,
      tval.tv_usec);
#endif

#if BUILDFLAG(IS_APPLE)
  t = Time::FromCFAbsoluteTime(std::numeric_limits<CFAbsoluteTime>::infinity());
  EXPECT_TRUE(t.is_max());
  EXPECT_EQ(std::numeric_limits<CFAbsoluteTime>::infinity(),
            t.ToCFAbsoluteTime());
#endif

#if BUILDFLAG(IS_WIN)
  FILETIME ftime;
  ftime.dwHighDateTime = std::numeric_limits<DWORD>::max();
  ftime.dwLowDateTime = std::numeric_limits<DWORD>::max();
  t = Time::FromFileTime(ftime);
  EXPECT_TRUE(t.is_max());
  ftime = t.ToFileTime();
  EXPECT_EQ(std::numeric_limits<DWORD>::max(), ftime.dwHighDateTime);
  EXPECT_EQ(std::numeric_limits<DWORD>::max(), ftime.dwLowDateTime);
#endif
}

TEST_F(TimeTest, Min) {
  constexpr Time kMin = Time::Min();
  static_assert(kMin.is_min());
  static_assert(kMin == Time::Min());
  EXPECT_LT(kMin, Time::Now());
  static_assert(kMin < Time());
  EXPECT_TRUE((Time::Now() - kMin).is_positive());
  EXPECT_TRUE((kMin - Time::Now()).is_negative());
}

TEST_F(TimeTest, TimeTOverflow) {
  // We always expect Max and Min Time values to map to the extreme of the range
  // of time_t because we have things that make this assumption - Even if such a
  // time were representable in time_t.
  EXPECT_EQ(std::numeric_limits<time_t>::max(), Time::Max().ToTimeT());
  EXPECT_EQ(std::numeric_limits<time_t>::min(), Time::Min().ToTimeT());

  // In the bad old days time_t was 32 bit. Occasionally it still is.
  // Usually it is 64 bit. It must be one or the other.
  constexpr bool time_t_is_32_bit = sizeof(time_t) == sizeof(int32_t);
  static_assert(time_t_is_32_bit || sizeof(time_t) == sizeof(int64_t));

  // base::Time internally represents time as microseconds since the Windows
  // epoch as an int64_t. When time_t is a int64_t of seconds since the Unix
  // epoch, time_t can represent the maxiumum value of base::Time. A 32 bit
  // time_t can not represent it.

  // If we have a 32 bit time_t, check that a non-infinite value of one
  // microsecond less than the max value of a base::Time still maps to the max
  // value of time_t.
  if (time_t_is_32_bit) {
    constexpr Time kMaxMinusOne =
        Time()   base::Microseconds(std::numeric_limits<int64_t>::max() - 1);
    static_assert(!kMaxMinusOne.is_max());
    EXPECT_EQ(std::numeric_limits<time_t>::max(), kMaxMinusOne.ToTimeT());
  }
  // Converting a base::Time to a time_t subtracts the value of the UnixEpoch in
  // microseconds since the Windows epoch from the current time value. As such
  // we expect a value of the minimum time plus one, subtracted by the UnixEpoch
  // value to be clamped by the TimeDelta math, meaning that we will see a
  // minimum value in the time_t, 32 bit or 64 bit
  constexpr Time kMinPlusOne =
      Time()   base::Microseconds(std::numeric_limits<int64_t>::min()   1);
  static_assert(!kMinPlusOne.is_min());
  EXPECT_EQ(std::numeric_limits<time_t>::min(), kMinPlusOne.ToTimeT());

  // We also expect the same behaviour for Min plus the Unix Epoch.
  constexpr Time kMinPlusUnix =
      Time()   base::Microseconds(std::numeric_limits<int64_t>::min()  
                                  Time::kTimeTToMicrosecondsOffset);
  static_assert(!kMinPlusUnix.is_min());
  EXPECT_EQ(std::numeric_limits<time_t>::min(), kMinPlusUnix.ToTimeT());

  // We expect Min plus the UnixEpoch plus 1 in microseconds to convert back to
  // one more than Min - a negative number of microseconds far before the
  // Windows epoch of 1601-01-01. It will representable in seconds as a 64 bit
  // time_t, but not on a 32 bit time_t, which can only represent values
  // starting from 1901-12-13
  constexpr Time kMinPlusUnixPlusOne =
      Time()   base::Microseconds(std::numeric_limits<int64_t>::min()  
                                  Time::kTimeTToMicrosecondsOffset   1);
  static_assert(!kMinPlusUnixPlusOne.is_min());
  if (time_t_is_32_bit) {
    EXPECT_EQ(std::numeric_limits<time_t>::min(),
              kMinPlusUnixPlusOne.ToTimeT());
  } else {
    EXPECT_NE(std::numeric_limits<time_t>::min(),
              kMinPlusUnixPlusOne.ToTimeT());
  }
}

#if BUILDFLAG(IS_ANDROID)
TEST_F(TimeTest, FromLocalExplodedCrashOnAndroid) {
  // This crashed inside Time:: FromLocalExploded() on Android 4.1.2.
  // See http://crbug.com/287821
  Time::Exploded midnight = {2013,  // year
                             10,    // month
                             0,     // day_of_week
                             13,    // day_of_month
                             0,     // hour
                             0,     // minute
                             0,     // second
  };
  // The string passed to putenv() must be a char* and the documentation states
  // that it 'becomes part of the environment', so use a static buffer.
  static char buffer[] = "TZ=America/Santiago";
  putenv(buffer);
  tzset();
  Time t;
  EXPECT_TRUE(Time::FromLocalExploded(midnight, &t));
  EXPECT_EQ(1381633200, t.ToTimeT());
}
#endif  // BUILDFLAG(IS_ANDROID)

// Regression test for https://crbug.com/1104442
TEST_F(TimeTest, Explode_Y10KCompliance) {
  constexpr int kDaysPerYear = 365;
  constexpr int64_t kHalfYearInMicros = Days(kDaysPerYear / 2).InMicroseconds();

  // The Y2038 issue occurs when a 32-bit signed integer overflows.
  constexpr int64_t kYear2038MicrosOffset =
      Time::kTimeTToMicrosecondsOffset  
      (std::numeric_limits<int32_t>::max() * Time::kMicrosecondsPerSecond);

  // 1 March 10000 at noon.
  constexpr int64_t kYear10000YearsOffset = 10000 - 1970;
  constexpr int kExtraLeapDaysOverThoseYears = 1947;
  constexpr int kDaysFromJanToMar10000 = 31   29;
  constexpr int64_t kMarch10000MicrosOffset =
      Time::kTimeTToMicrosecondsOffset  
      Days(kYear10000YearsOffset * kDaysPerYear   kExtraLeapDaysOverThoseYears  
           kDaysFromJanToMar10000)
          .InMicroseconds()  
      Hours(12).InMicroseconds();

  // Windows uses a 64-bit signed integer type that reperesents the number of
  // 1/10 microsecond ticks.
  constexpr int64_t kWindowsMaxMicrosOffset =
      std::numeric_limits<int64_t>::max() / 10;

  // ICU's Calendar API uses double values. Thus, the maximum supported value is
  // the maximum integer that can be represented by a double.
  static_assert(std::numeric_limits<double>::radix == 2);
  constexpr int64_t kMaxIntegerAsDoubleMillis =
      int64_t{1} << std::numeric_limits<double>::digits;
  constexpr int64_t kIcuMaxMicrosOffset =
      Time::kTimeTToMicrosecondsOffset  
      (kMaxIntegerAsDoubleMillis * Time::kMicrosecondsPerMillisecond   999);

  const auto make_time = [](int64_t micros) {
    return Time::FromDeltaSinceWindowsEpoch(Microseconds(micros));
  };

  const struct TestCase {
    Time time;
    Time::Exploded expected;
  } kTestCases[] = {
      // A very long time ago.
      {Time::Min(), Time::Exploded{-290677, 12, 4, 23, 19, 59, 5, 224}},

      // Before/On/After 1 Jan 1601.
      {make_time(-kHalfYearInMicros),
       Time::Exploded{1600, 7, 1, 3, 0, 0, 0, 0}},
      {make_time(0), Time::Exploded{1601, 1, 1, 1, 0, 0, 0, 0}},
      {make_time(kHalfYearInMicros), Time::Exploded{1601, 7, 1, 2, 0, 0, 0, 0}},

      // Before/On/After 1 Jan 1970.
      {make_time(Time::kTimeTToMicrosecondsOffset - kHalfYearInMicros),
       Time::Exploded{1969, 7, 4, 3, 0, 0, 0, 0}},
      {make_time(Time::kTimeTToMicrosecondsOffset),
       Time::Exploded{1970, 1, 4, 1, 0, 0, 0, 0}},
      {make_time(Time::kTimeTToMicrosecondsOffset   kHalfYearInMicros),
       Time::Exploded{1970, 7, 4, 2, 0, 0, 0, 0}},

      // Before/On/After 19 January 2038.
      {make_time(kYear2038MicrosOffset - kHalfYearInMicros),
       Time::Exploded{2037, 7, 2, 21, 3, 14, 7, 0}},
      {make_time(kYear2038MicrosOffset),
       Time::Exploded{2038, 1, 2, 19, 3, 14, 7, 0}},
      {make_time(kYear2038MicrosOffset   kHalfYearInMicros),
       Time::Exploded{2038, 7, 2, 20, 3, 14, 7, 0}},

      // Before/On/After 1 March 10000 at noon.
      {make_time(kMarch10000MicrosOffset - kHalfYearInMicros),
       Time::Exploded{9999, 9, 3, 1, 12, 0, 0, 0}},
      {make_time(kMarch10000MicrosOffset),
       Time::Exploded{10000, 3, 3, 1, 12, 0, 0, 0}},
      {make_time(kMarch10000MicrosOffset   kHalfYearInMicros),
       Time::Exploded{10000, 8, 3, 30, 12, 0, 0, 0}},

      // Before/On/After Windows Max (14 September 30828).
      {make_time(kWindowsMaxMicrosOffset - kHalfYearInMicros),
       Time::Exploded{30828, 3, 4, 16, 2, 48, 5, 477}},
      {make_time(kWindowsMaxMicrosOffset),
       Time::Exploded{30828, 9, 4, 14, 2, 48, 5, 477}},
      {make_time(kWindowsMaxMicrosOffset   kHalfYearInMicros),
       Time::Exploded{30829, 3, 4, 15, 2, 48, 5, 477}},

      // Before/On/After ICU Max.
      {make_time(kIcuMaxMicrosOffset - kHalfYearInMicros),
       Time::Exploded{287396, 4, 3, 13, 8, 59, 0, 992}},
      {make_time(kIcuMaxMicrosOffset),
       Time::Exploded{287396, 10, 3, 12, 8, 59, 0, 992}},
      {make_time(kIcuMaxMicrosOffset   kHalfYearInMicros),
       Time::Exploded{287397, 4, 3, 12, 8, 59, 0, 992}},

      // A very long time from now.
      {Time::Max(), Time::Exploded{293878, 1, 4, 10, 4, 0, 54, 775}},
  };

  for (const TestCase& test_case : kTestCases) {
    SCOPED_TRACE(testing::Message() << "Time: " << test_case.time);

    Time::Exploded exploded = {};
    test_case.time.UTCExplode(&exploded);

    // Confirm the implementation provides a correct conversion for all inputs
    // within the guaranteed range (as discussed in the header comments). If an
    // implementation provides a result for inputs outside the guaranteed range,
    // the result must still be correct.
    if (exploded.HasValidValues()) {
      EXPECT_EQ(test_case.expected.year, exploded.year);
      EXPECT_EQ(test_case.expected.month, exploded.month);
      EXPECT_EQ(test_case.expected.day_of_week, exploded.day_of_week);
      EXPECT_EQ(test_case.expected.day_of_month, exploded.day_of_month);
      EXPECT_EQ(test_case.expected.hour, exploded.hour);
      EXPECT_EQ(test_case.expected.minute, exploded.minute);
      EXPECT_EQ(test_case.expected.second, exploded.second);
      EXPECT_EQ(test_case.expected.millisecond, exploded.millisecond);
    } else {
      // The implementation could not provide a conversion. That is only allowed
      // for inputs outside the guaranteed range.
      const bool is_in_range =
          test_case.time >= make_time(0) &&
          test_case.time <= make_time(kWindowsMaxMicrosOffset);
      EXPECT_FALSE(is_in_range);
    }
  }
}

#if BUILDFLAG(IS_FUCHSIA) || BUILDFLAG(IS_CHROMEOS)
// Regression tests for https://crbug.com/1198313: base::Time::UTCExplode and
// base::Time::LocalExplode should not be locale-dependent.
TEST_F(TimeTest, UTCExplodedIsLocaleIndependent) {
  // Time-to-Exploded could be using libc or ICU functions.
  // Set the ICU locale and timezone and the libc timezone.
  // We're not setting the libc locale because the libc time functions are
  // locale-independent and the th_TH.utf8 locale was not available on all
  // trybots at the time this test was added.
  // th-TH maps to a non-gregorian calendar.
  test::ScopedRestoreICUDefaultLocale scoped_icu_locale(kThaiLocale);
  test::ScopedRestoreDefaultTimezone scoped_timezone(kBangkokTimeZoneId);
  ScopedLibcTZ scoped_libc_tz(kBangkokTimeZoneId);
  ASSERT_TRUE(scoped_libc_tz.is_success());

  Time::Exploded utc_exploded_orig;
  utc_exploded_orig.year = 2020;
  utc_exploded_orig.month = 7;
  utc_exploded_orig.day_of_week = 5;  // Friday
  utc_exploded_orig.day_of_month = 3;
  utc_exploded_orig.hour = 12;
  utc_exploded_orig.minute = 0;
  utc_exploded_orig.second = 0;
  utc_exploded_orig.millisecond = 0;

  Time time;
  ASSERT_TRUE(base::Time::FromUTCExploded(utc_exploded_orig, &time));

  // Round trip to UTC Exploded should produce the exact same result.
  Time::Exploded utc_exploded;
  time.UTCExplode(&utc_exploded);
  EXPECT_EQ(utc_exploded_orig.year, utc_exploded.year);
  EXPECT_EQ(utc_exploded_orig.month, utc_exploded.month);
  EXPECT_EQ(utc_exploded_orig.day_of_week, utc_exploded.day_of_week);
  EXPECT_EQ(utc_exploded_orig.day_of_month, utc_exploded.day_of_month);
  EXPECT_EQ(utc_exploded_orig.hour, utc_exploded.hour);
  EXPECT_EQ(utc_exploded_orig.minute, utc_exploded.minute);
  EXPECT_EQ(utc_exploded_orig.second, utc_exploded.second);
  EXPECT_EQ(utc_exploded_orig.millisecond, utc_exploded.millisecond);
}

TEST_F(TimeTest, LocalExplodedIsLocaleIndependent) {
  // Time-to-Exploded could be using libc or ICU functions.
  // Set the ICU locale and timezone and the libc timezone.
  // We're not setting the libc locale because the libc time functions are
  // locale-independent and the th_TH.utf8 locale was not available on all
  // trybots at the time this test was added.
  // th-TH maps to a non-gregorian calendar.
  test::ScopedRestoreICUDefaultLocale scoped_icu_locale(kThaiLocale);
  test::ScopedRestoreDefaultTimezone scoped_timezone(kBangkokTimeZoneId);
  ScopedLibcTZ scoped_libc_tz(kBangkokTimeZoneId);
  ASSERT_TRUE(scoped_libc_tz.is_success());

  Time::Exploded utc_exploded_orig;
  utc_exploded_orig.year = 2020;
  utc_exploded_orig.month = 7;
  utc_exploded_orig.day_of_week = 5;  // Friday
  utc_exploded_orig.day_of_month = 3;
  utc_exploded_orig.hour = 12;
  utc_exploded_orig.minute = 0;
  utc_exploded_orig.second = 0;
  utc_exploded_orig.millisecond = 0;

  Time time;
  ASSERT_TRUE(base::Time::FromUTCExploded(utc_exploded_orig, &time));

  std::optional<TimeDelta> expected_delta =
      GetTimeZoneOffsetAtTime(kBangkokTimeZoneId, time);

  ASSERT_TRUE(expected_delta.has_value());

  // This is to be sure that the day has not changed
  ASSERT_LT(*expected_delta, base::Hours(12));

  Time::Exploded local_exploded;
  time.LocalExplode(&local_exploded);

  TimeDelta actual_delta = TimePassedAfterMidnight(local_exploded) -
                           TimePassedAfterMidnight(utc_exploded_orig);

  EXPECT_EQ(utc_exploded_orig.year, local_exploded.year);
  EXPECT_EQ(utc_exploded_orig.month, local_exploded.month);
  EXPECT_EQ(utc_exploded_orig.day_of_week, local_exploded.day_of_week);
  EXPECT_EQ(utc_exploded_orig.day_of_month, local_exploded.day_of_month);
  EXPECT_EQ(actual_delta, *expected_delta);
}
#endif  // BUILDFLAG(IS_FUCHSIA) || BUILDFLAG(IS_CHROMEOS)

TEST_F(TimeTest, FromExploded_MinMax) {
  Time::Exploded exploded = {0};
  exploded.month = 1;
  exploded.day_of_month = 1;

  Time parsed_time;

  if (Time::kExplodedMinYear != std::numeric_limits<int>::min()) {
    exploded.year = Time::kExplodedMinYear;
    EXPECT_TRUE(Time::FromUTCExploded(exploded, &parsed_time));
#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
    // On Windows, January 1, 1601 00:00:00 is actually the null time.
    EXPECT_FALSE(parsed_time.is_null());
#endif

#if !BUILDFLAG(IS_ANDROID) && !BUILDFLAG(IS_APPLE)
    // The dates earlier than |kExplodedMinYear| that don't work are OS version
    // dependent on Android and Mac (for example, macOS 10.13 seems to support
    // dates before 1902).
    exploded.year--;
    EXPECT_FALSE(Time::FromUTCExploded(exploded, &parsed_time));
    EXPECT_TRUE(parsed_time.is_null());
#endif
  }

  if (Time::kExplodedMaxYear != std::numeric_limits<int>::max()) {
    exploded.year = Time::kExplodedMaxYear;
    exploded.month = 12;
    exploded.day_of_month = 31;
    exploded.hour = 23;
    exploded.minute = 59;
    exploded.second = 59;
    exploded.millisecond = 999;
    EXPECT_TRUE(Time::FromUTCExploded(exploded, &parsed_time));
    EXPECT_FALSE(parsed_time.is_null());

    exploded.year  ;
    EXPECT_FALSE(Time::FromUTCExploded(exploded, &parsed_time));
    EXPECT_TRUE(parsed_time.is_null());
  }
}

class TimeOverride {
 public:
  static Time Now() {
    now_time_  = Seconds(1);
    return now_time_;
  }

  static Time now_time_;
};

// static
Time TimeOverride::now_time_;

// Disabled on Android due to flakes; see https://crbug.com/1474884.
#if BUILDFLAG(IS_ANDROID)
#define MAYBE_NowOverride DISABLED_NowOverride
#else
#define MAYBE_NowOverride NowOverride
#endif
TEST_F(TimeTest, MAYBE_NowOverride) {
  TimeOverride::now_time_ = Time::UnixEpoch();

  // Choose a reference time that we know to be in the past but close to now.
  Time build_time = GetBuildTime();

  // Override is not active. All Now() methods should return a time greater than
  // the build time.
  EXPECT_LT(build_time, Time::Now());
  EXPECT_GT(Time::Max(), Time::Now());
  EXPECT_LT(build_time, subtle::TimeNowIgnoringOverride());
  EXPECT_GT(Time::Max(), subtle::TimeNowIgnoringOverride());
  EXPECT_LT(build_time, Time::NowFromSystemTime());
  EXPECT_GT(Time::Max(), Time::NowFromSystemTime());
  EXPECT_LT(build_time, subtle::TimeNowFromSystemTimeIgnoringOverride());
  EXPECT_GT(Time::Max(), subtle::TimeNowFromSystemTimeIgnoringOverride());

  {
    // Set override.
    subtle::ScopedTimeClockOverrides overrides(&TimeOverride::Now, nullptr,
                                               nullptr);

    // Overridden value is returned and incremented when Now() or
    // NowFromSystemTime() is called.
    EXPECT_EQ(Time::UnixEpoch()   Seconds(1), Time::Now());
    EXPECT_EQ(Time::UnixEpoch()   Seconds(2), Time::Now());
    EXPECT_EQ(Time::UnixEpoch()   Seconds(3), Time::NowFromSystemTime());
    EXPECT_EQ(Time::UnixEpoch()   Seconds(4), Time::NowFromSystemTime());

    // IgnoringOverride methods still return real time.
    EXPECT_LT(build_time, subtle::TimeNowIgnoringOverride());
    EXPECT_GT(Time::Max(), subtle::TimeNowIgnoringOverride());
    EXPECT_LT(build_time, subtle::TimeNowFromSystemTimeIgnoringOverride());
    EXPECT_GT(Time::Max(), subtle::TimeNowFromSystemTimeIgnoringOverride());

    // IgnoringOverride methods didn't call NowOverrideClock::Now().
    EXPECT_EQ(Time::UnixEpoch()   Seconds(5), Time::Now());
    EXPECT_EQ(Time::UnixEpoch()   Seconds(6), Time::NowFromSystemTime());
  }

  // All methods return real time again.
  EXPECT_LT(build_time, Time::Now());
  EXPECT_GT(Time::Max(), Time::Now());
  EXPECT_LT(build_time, subtle::TimeNowIgnoringOverride());
  EXPECT_GT(Time::Max(), subtle::TimeNowIgnoringOverride());
  EXPECT_LT(build_time, Time::NowFromSystemTime());
  EXPECT_GT(Time::Max(), Time::NowFromSystemTime());
  EXPECT_LT(build_time, subtle::TimeNowFromSystemTimeIgnoringOverride());
  EXPECT_GT(Time::Max(), subtle::TimeNowFromSystemTimeIgnoringOverride());
}

#undef MAYBE_NowOverride

#if BUILDFLAG(IS_FUCHSIA)
TEST(ZxTimeTest, ToFromConversions) {
  Time unix_epoch = Time::UnixEpoch();
  EXPECT_EQ(unix_epoch.ToZxTime(), 0);
  EXPECT_EQ(Time::FromZxTime(6000000000), unix_epoch   Seconds(6));

  TimeTicks ticks_now = TimeTicks::Now();
  EXPECT_GE(ticks_now.ToZxTime(), 0);
  TimeTicks ticks_later = ticks_now   Seconds(2);
  EXPECT_EQ((ticks_later.ToZxTime() - ticks_now.ToZxTime()), 2000000000);
  EXPECT_EQ(TimeTicks::FromZxTime(3000000000), TimeTicks()   Seconds(3));

  EXPECT_EQ(TimeDelta().ToZxDuration(), 0);
  EXPECT_EQ(TimeDelta::FromZxDuration(0), TimeDelta());

  EXPECT_EQ(Seconds(2).ToZxDuration(), 2000000000);
  EXPECT_EQ(TimeDelta::FromZxDuration(4000000000), Seconds(4));
}
#endif  // BUILDFLAG(IS_FUCHSIA)

TEST(TimeTicks, Deltas) {
  for (int index = 0; index < 50; index  ) {
    TimeTicks ticks_start = TimeTicks::Now();
    base::PlatformThread::Sleep(base::Milliseconds(10));
    TimeTicks ticks_stop = TimeTicks::Now();
    TimeDelta delta = ticks_stop - ticks_start;
    // Note:  Although we asked for a 10ms sleep, if the
    // time clock has a finer granularity than the Sleep()
    // clock, it is quite possible to wakeup early.  Here
    // is how that works:
    //      Time(ms timer)      Time(us timer)
    //          5                   5010
    //          6                   6010
    //          7                   7010
    //          8                   8010
    //          9                   9500
    // Elapsed  4ms                 3990us
    //
    // Unfortunately, our InMilliseconds() function truncates
    // rather than rounds.  We should consider fixing this
    // so that our averages come out better.
    EXPECT_GE(delta.InMilliseconds(), 9);
    EXPECT_GE(delta.InMicroseconds(), 9500);
    EXPECT_EQ(delta.InSeconds(), 0);
  }
}

static void HighResClockTest(TimeTicks (*GetTicks)()) {
  // IsHighResolution() is false on some systems.  Since the product still works
  // even if it's false, it makes this entire test questionable.
  if (!TimeTicks::IsHighResolution())
    return;

  // Why do we loop here?
  // We're trying to measure that intervals increment in a VERY small amount
  // of time --  less than 15ms.  Unfortunately, if we happen to have a
  // context switch in the middle of our test, the context switch could easily
  // exceed our limit.  So, we iterate on this several times.  As long as we're
  // able to detect the fine-granularity timers at least once, then the test
  // has succeeded.

  const int kTargetGranularityUs = 15000;  // 15ms

  bool success = false;
  int retries = 100;  // Arbitrary.
  TimeDelta delta;
  while (!success && retries--) {
    TimeTicks ticks_start = GetTicks();
    // Loop until we can detect that the clock has changed.  Non-HighRes timers
    // will increment in chunks, e.g. 15ms.  By spinning until we see a clock
    // change, we detect the minimum time between measurements.
    do {
      delta = GetTicks() - ticks_start;
    } while (delta.InMilliseconds() == 0);

    if (delta.InMicroseconds() <= kTargetGranularityUs)
      success = true;
  }

  // In high resolution mode, we expect to see the clock increment
  // in intervals less than 15ms.
  EXPECT_TRUE(success);
}

TEST(TimeTicks, HighRes) {
  HighResClockTest(&TimeTicks::Now);
}

class TimeTicksOverride {
 public:
  static TimeTicks Now() {
    now_ticks_  = Seconds(1);
    return now_ticks_;
  }

  static TimeTicks now_ticks_;
};

// static
TimeTicks TimeTicksOverride::now_ticks_;

TEST(TimeTicks, NowOverride) {
  TimeTicksOverride::now_ticks_ = TimeTicks::Min();

  // Override is not active. All Now() methods should return a sensible value.
  EXPECT_LT(TimeTicks::Min(), TimeTicks::UnixEpoch());
  EXPECT_LT(TimeTicks::UnixEpoch(), TimeTicks::Now());
  EXPECT_GT(TimeTicks::Max(), TimeTicks::Now());
  EXPECT_LT(TimeTicks::UnixEpoch(), subtle::TimeTicksNowIgnoringOverride());
  EXPECT_GT(TimeTicks::Max(), subtle::TimeTicksNowIgnoringOverride());

  {
    // Set override.
    subtle::ScopedTimeClockOverrides overrides(nullptr, &TimeTicksOverride::Now,
                                               nullptr);

    // Overridden value is returned and incremented when Now() is called.
    EXPECT_EQ(TimeTicks::Min()   Seconds(1), TimeTicks::Now());
    EXPECT_EQ(TimeTicks::Min()   Seconds(2), TimeTicks::Now());

    // NowIgnoringOverride() still returns real ticks.
    EXPECT_LT(TimeTicks::UnixEpoch(), subtle::TimeTicksNowIgnoringOverride());
    EXPECT_GT(TimeTicks::Max(), subtle::TimeTicksNowIgnoringOverride());

    // IgnoringOverride methods didn't call NowOverrideTickClock::NowTicks().
    EXPECT_EQ(TimeTicks::Min()   Seconds(3), TimeTicks::Now());
  }

  // All methods return real ticks again.
  EXPECT_LT(TimeTicks::UnixEpoch(), TimeTicks::Now());
  EXPECT_GT(TimeTicks::Max(), TimeTicks::Now());
  EXPECT_LT(TimeTicks::UnixEpoch(), subtle::TimeTicksNowIgnoringOverride());
  EXPECT_GT(TimeTicks::Max(), subtle::TimeTicksNowIgnoringOverride());
}

class ThreadTicksOverride {
 public:
  static ThreadTicks Now() {
    now_ticks_  = Seconds(1);
    return now_ticks_;
  }

  static ThreadTicks now_ticks_;
};

// static
ThreadTicks ThreadTicksOverride::now_ticks_;

// IOS doesn't support ThreadTicks::Now().
#if BUILDFLAG(IS_IOS)
#define MAYBE_NowOverride DISABLED_NowOverride
#else
#define MAYBE_NowOverride NowOverride
#endif
TEST(ThreadTicks, MAYBE_NowOverride) {
  ThreadTicksOverride::now_ticks_ = ThreadTicks::Min();

  // Override is not active. All Now() methods should return a sensible value.
  ThreadTicks initial_thread_ticks = ThreadTicks::Now();
  EXPECT_LE(initial_thread_ticks, ThreadTicks::Now());
  EXPECT_GT(ThreadTicks::Max(), ThreadTicks::Now());
  EXPECT_LE(initial_thread_ticks, subtle::ThreadTicksNowIgnoringOverride());
  EXPECT_GT(ThreadTicks::Max(), subtle::ThreadTicksNowIgnoringOverride());

  {
    // Set override.
    subtle::ScopedTimeClockOverrides overrides(nullptr, nullptr,
                                               &ThreadTicksOverride::Now);

    // Overridden value is returned and incremented when Now() is called.
    EXPECT_EQ(ThreadTicks::Min()   Seconds(1), ThreadTicks::Now());
    EXPECT_EQ(ThreadTicks::Min()   Seconds(2), ThreadTicks::Now());

    // NowIgnoringOverride() still returns real ticks.
    EXPECT_LE(initial_thread_ticks, subtle::ThreadTicksNowIgnoringOverride());
    EXPECT_GT(ThreadTicks::Max(), subtle::ThreadTicksNowIgnoringOverride());

    // IgnoringOverride methods didn't call NowOverrideTickClock::NowTicks().
    EXPECT_EQ(ThreadTicks::Min()   Seconds(3), ThreadTicks::Now());
  }

  // All methods return real ticks again.
  EXPECT_LE(initial_thread_ticks, ThreadTicks::Now());
  EXPECT_GT(ThreadTicks::Max(), ThreadTicks::Now());
  EXPECT_LE(initial_thread_ticks, subtle::ThreadTicksNowIgnoringOverride());
  EXPECT_GT(ThreadTicks::Max(), subtle::ThreadTicksNowIgnoringOverride());
}

TEST(ThreadTicks, ThreadNow) {
  if (ThreadTicks::IsSupported()) {
    ThreadTicks::WaitUntilInitialized();
    TimeTicks begin = TimeTicks::Now();
    ThreadTicks begin_thread = ThreadTicks::Now();
    // Make sure that ThreadNow value is non-zero.
    EXPECT_GT(begin_thread, ThreadTicks());
    // Sleep for 10 milliseconds to get the thread de-scheduled.
    base::PlatformThread::Sleep(base::Milliseconds(10));
    ThreadTicks end_thread = ThreadTicks::Now();
    TimeTicks end = TimeTicks::Now();
    TimeDelta delta = end - begin;
    TimeDelta delta_thread = end_thread - begin_thread;
    // Make sure that some thread time have elapsed.
    EXPECT_GE(delta_thread.InMicroseconds(), 0);
    // But the thread time is at least 9ms less than clock time.
    TimeDelta difference = delta - delta_thread;
    EXPECT_GE(difference.InMicroseconds(), 9500);
  }
}

TEST(TimeTicks, SnappedToNextTickBasic) {
  base::TimeTicks phase = base::TimeTicks::FromInternalValue(4000);
  base::TimeDelta interval = base::Microseconds(1000);
  base::TimeTicks timestamp;

  // Timestamp in previous interval.
  timestamp = base::TimeTicks::FromInternalValue(3500);
  EXPECT_EQ(4000,
            timestamp.SnappedToNextTick(phase, interval).ToInternalValue());

  // Timestamp in next interval.
  timestamp = base::TimeTicks::FromInternalValue(4500);
  EXPECT_EQ(5000,
            timestamp.SnappedToNextTick(phase, interval).ToInternalValue());

  // Timestamp multiple intervals before.
  timestamp = base::TimeTicks::FromInternalValue(2500);
  EXPECT_EQ(3000,
            timestamp.SnappedToNextTick(phase, interval).ToInternalValue());

  // Timestamp multiple intervals after.
  timestamp = base::TimeTicks::FromInternalValue(6500);
  EXPECT_EQ(7000,
            timestamp.SnappedToNextTick(phase, interval).ToInternalValue());

  // Timestamp on previous interval.
  timestamp = base::TimeTicks::FromInternalValue(3000);
  EXPECT_EQ(3000,
            timestamp.SnappedToNextTick(phase, interval).ToInternalValue());

  // Timestamp on next interval.
  timestamp = base::TimeTicks::FromInternalValue(5000);
  EXPECT_EQ(5000,
            timestamp.SnappedToNextTick(phase, interval).ToInternalValue());

  // Timestamp equal to phase.
  timestamp = base::TimeTicks::FromInternalValue(4000);
  EXPECT_EQ(4000,
            timestamp.SnappedToNextTick(phase, interval).ToInternalValue());
}

TEST(TimeTicks, SnappedToNextTickOverflow) {
  // int(big_timestamp / interval) < 0, so this causes a crash if the number of
  // intervals elapsed is attempted to be stored in an int.
  base::TimeTicks phase = base::TimeTicks::FromInternalValue(0);
  base::TimeDelta interval = base::Microseconds(4000);
  base::TimeTicks big_timestamp =
      base::TimeTicks::FromInternalValue(8635916564000);

  EXPECT_EQ(8635916564000,
            big_timestamp.SnappedToNextTick(phase, interval).ToInternalValue());
  EXPECT_EQ(8635916564000,
            big_timestamp.SnappedToNextTick(big_timestamp, interval)
                .ToInternalValue());
}

#if BUILDFLAG(IS_ANDROID)
TEST(TimeTicks, Android_FromUptimeMillis_ClocksMatch) {
  JNIEnv* const env = android::AttachCurrentThread();
  android::ScopedJavaLocalRef<jclass> clazz(
      android::GetClass(env, "android/os/SystemClock"));
  ASSERT_TRUE(clazz.obj());
  const jmethodID method_id =
      android::MethodID::Get<android::MethodID::TYPE_STATIC>(
          env, clazz.obj(), "uptimeMillis", "()J");
  ASSERT_FALSE(!method_id);
  // Subtract 1ms from the expected lower bound to allow millisecond-level
  // truncation performed in uptimeMillis().
  const TimeTicks lower_bound_ticks = TimeTicks::Now() - Milliseconds(1);
  const TimeTicks converted_ticks = TimeTicks::FromUptimeMillis(
      env->CallStaticLongMethod(clazz.obj(), method_id));
  const TimeTicks upper_bound_ticks = TimeTicks::Now();
  EXPECT_LE(lower_bound_ticks, converted_ticks);
  EXPECT_GE(upper_bound_ticks, converted_ticks);
}

TEST(TimeTicks, Android_FromJavaNanoTime_ClocksMatch) {
  JNIEnv* const env = android::AttachCurrentThread();
  android::ScopedJavaLocalRef<jclass> clazz(
      android::GetClass(env, "java/lang/System"));
  ASSERT_TRUE(clazz.obj());
  const jmethodID method_id =
      android::MethodID::Get<android::MethodID::TYPE_STATIC>(env, clazz.obj(),
                                                             "nanoTime", "()J");
  ASSERT_FALSE(!method_id);
  const TimeTicks lower_bound_ticks = TimeTicks::Now();
  const TimeTicks converted_ticks = TimeTicks::FromJavaNanoTime(
      env->CallStaticLongMethod(clazz.obj(), method_id));
  // Add 1us to the expected upper bound to allow microsecond-level
  // truncation performed in TimeTicks::Now().
  const TimeTicks upper_bound_ticks = TimeTicks::Now()   Microseconds(1);
  EXPECT_LE(lower_bound_ticks, converted_ticks);
  EXPECT_GE(upper_bound_ticks, converted_ticks);
}
#endif  // BUILDFLAG(IS_ANDROID)

class LiveTicksOverride {
 public:
  static LiveTicks Now() {
    now_ticks_  = Seconds(1);
    return now_ticks_;
  }

  static LiveTicks now_ticks_;
};

// static
LiveTicks LiveTicksOverride::now_ticks_;

TEST(LiveTicks, NowOverride) {
  LiveTicksOverride::now_ticks_ = LiveTicks::Min();

  // Override is not active. All Now() methods should return a sensible value.
  LiveTicks initial_live_ticks = LiveTicks::Now();
  EXPECT_LE(initial_live_ticks, LiveTicks::Now());
  EXPECT_LT(LiveTicks::Now(), LiveTicks::Max());
  EXPECT_LE(initial_live_ticks, subtle::LiveTicksNowIgnoringOverride());
  EXPECT_LT(subtle::LiveTicksNowIgnoringOverride(), LiveTicks::Max());

  {
    // Set override.
    subtle::ScopedTimeClockOverrides overrides(nullptr, nullptr, nullptr,
                                               &LiveTicksOverride::Now);

    // Overridden value is returned and incremented when Now() is called.
    EXPECT_EQ(LiveTicks::Min()   Seconds(1), LiveTicks::Now());
    EXPECT_EQ(LiveTicks::Min()   Seconds(2), LiveTicks::Now());

    // NowIgnoringOverride() still returns real ticks.
    EXPECT_LE(initial_live_ticks, subtle::LiveTicksNowIgnoringOverride());
    EXPECT_LT(subtle::LiveTicksNowIgnoringOverride(), LiveTicks::Max());

    // IgnoringOverride methods didn't call NowOverrideTickClock::NowTicks().
    EXPECT_EQ(LiveTicks::Min()   Seconds(3), LiveTicks::Now());
  }

  // All methods return real ticks again.
  EXPECT_LE(initial_live_ticks, LiveTicks::Now());
  EXPECT_LT(LiveTicks::Now(), LiveTicks::Max());
  EXPECT_LE(initial_live_ticks, subtle::LiveTicksNowIgnoringOverride());
  EXPECT_LT(subtle::LiveTicksNowIgnoringOverride(), LiveTicks::Max());
}

TEST(TimeDelta, FromAndIn) {
  // static_assert also checks that the contained expression is a constant
  // expression, meaning all its components are suitable for initializing global
  // variables.
  static_assert(Days(2) == Hours(48));
  static_assert(Hours(3) == Minutes(180));
  static_assert(Minutes(2) == Seconds(120));
  static_assert(Seconds(2) == Milliseconds(2000));
  static_assert(Milliseconds(2) == Microseconds(2000));
  static_assert(Seconds(2.3) == Milliseconds(2300));
  static_assert(Milliseconds(2.5) == Microseconds(2500));
  static_assert(Days(13).InDays() == 13);
  static_assert(Hours(13).InHours() == 13);
  static_assert(Minutes(13).InMinutes() == 13);
  static_assert(Seconds(13).InSeconds() == 13);
  static_assert(Seconds(13).InSecondsF() == 13.0);
  static_assert(Milliseconds(13).InMilliseconds() == 13);
  static_assert(Milliseconds(13).InMillisecondsF() == 13.0);
  static_assert(Seconds(13.1).InSeconds() == 13);
  static_assert(Seconds(13.1).InSecondsF() == 13.1);
  static_assert(Milliseconds(13.3).InMilliseconds() == 13);
  static_assert(Milliseconds(13.3).InMillisecondsF() == 13.3);
  static_assert(Microseconds(13).InMicroseconds() == 13);
  static_assert(Microseconds(13.3).InMicroseconds() == 13);
  static_assert(Milliseconds(3.45678).InMillisecondsF() == 3.456);
  static_assert(Nanoseconds(12345).InNanoseconds() == 12000);
  static_assert(Nanoseconds(12345.678).InNanoseconds() == 12000);
}

TEST(TimeDelta, InRoundsTowardsZero) {
  static_assert(Hours(23).InDays() == 0);
  static_assert(Hours(-23).InDays() == 0);
  static_assert(Minutes(59).InHours() == 0);
  static_assert(Minutes(-59).InHours() == 0);
  static_assert(Seconds(59).InMinutes() == 0);
  static_assert(Seconds(-59).InMinutes() == 0);
  static_assert(Milliseconds(999).InSeconds() == 0);
  static_assert(Milliseconds(-999).InSeconds() == 0);
  static_assert(Microseconds(999).InMilliseconds() == 0);
  static_assert(Microseconds(-999).InMilliseconds() == 0);
}

TEST(TimeDelta, InDaysFloored) {
  static_assert(Hours(-25).InDaysFloored() == -2);
  static_assert(Hours(-24).InDaysFloored() == -1);
  static_assert(Hours(-23).InDaysFloored() == -1);

  static_assert(Hours(-1).InDaysFloored() == -1);
  static_assert(Hours(0).InDaysFloored() == 0);
  static_assert(Hours(1).InDaysFloored() == 0);

  static_assert(Hours(23).InDaysFloored() == 0);
  static_assert(Hours(24).InDaysFloored() == 1);
  static_assert(Hours(25).InDaysFloored() == 1);
}

TEST(TimeDelta, InSecondsFloored) {
  static_assert(Seconds(13.1).InSecondsFloored() == 13);
  static_assert(Seconds(13.9).InSecondsFloored() == 13);
  static_assert(Seconds(13).InSecondsFloored() == 13);

  static_assert(Milliseconds(1001).InSecondsFloored() == 1);
  static_assert(Milliseconds(1000).InSecondsFloored() == 1);
  static_assert(Milliseconds(999).InSecondsFloored() == 0);
  static_assert(Milliseconds(1).InSecondsFloored() == 0);
  static_assert(Milliseconds(0).InSecondsFloored() == 0);
  static_assert(Milliseconds(-1).InSecondsFloored() == -1);
  static_assert(Milliseconds(-1000).InSecondsFloored() == -1);
  static_assert(Milliseconds(-1001).InSecondsFloored() == -2);
}

TEST(TimeDelta, InMillisecondsRoundedUp) {
  static_assert(Microseconds(-1001).InMillisecondsRoundedUp() == -1);
  static_assert(Microseconds(-1000).InMillisecondsRoundedUp() == -1);
  static_assert(Microseconds(-999).InMillisecondsRoundedUp() == 0);

  static_assert(Microseconds(-1).InMillisecondsRoundedUp() == 0);
  static_assert(Microseconds(0).InMillisecondsRoundedUp() == 0);
  static_assert(Microseconds(1).InMillisecondsRoundedUp() == 1);

  static_assert(Microseconds(999).InMillisecondsRoundedUp() == 1);
  static_assert(Microseconds(1000).InMillisecondsRoundedUp() == 1);
  static_assert(Microseconds(1001).InMillisecondsRoundedUp() == 2);
}

// Check that near-min/max values saturate rather than overflow when converted
// lossily with InXXX() functions.  Only integral hour, minute, and nanosecond
// conversions are checked, since those are the only cases where the return type
// is small enough for saturation or overflow to occur.
TEST(TimeDelta, InXXXOverflow) {
  constexpr TimeDelta kLargeDelta =
      Microseconds(std::numeric_limits<int64_t>::max() - 1);
  static_assert(!kLargeDelta.is_max());
  static_assert(std::numeric_limits<int>::max() == kLargeDelta.InHours());
  static_assert(std::numeric_limits<int>::max() == kLargeDelta.InMinutes());
  static_assert(
      std::numeric_limits<int64_t>::max() == kLargeDelta.InNanoseconds(), "");

  constexpr TimeDelta kLargeNegative =
      Microseconds(std::numeric_limits<int64_t>::min()   1);
  static_assert(!kLargeNegative.is_min());
  static_assert(std::numeric_limits<int>::min() == kLargeNegative.InHours(),
                "");
  static_assert(std::numeric_limits<int>::min() == kLargeNegative.InMinutes(),
                "");
  static_assert(
      std::numeric_limits<int64_t>::min() == kLargeNegative.InNanoseconds(),
      "");
}

#if BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)
TEST(TimeDelta, TimeSpecConversion) {
  TimeDelta delta = Seconds(0);
  struct timespec result = delta.ToTimeSpec();
  EXPECT_EQ(result.tv_sec, 0);
  EXPECT_EQ(result.tv_nsec, 0);
  EXPECT_EQ(delta, TimeDelta::FromTimeSpec(result));

  delta = Seconds(1);
  result = delta.ToTimeSpec();
  EXPECT_EQ(result.tv_sec, 1);
  EXPECT_EQ(result.tv_nsec, 0);
  EXPECT_EQ(delta, TimeDelta::FromTimeSpec(result));

  delta = Microseconds(1);
  result = delta.ToTimeSpec();
  EXPECT_EQ(result.tv_sec, 0);
  EXPECT_EQ(result.tv_nsec, 1000);
  EXPECT_EQ(delta, TimeDelta::FromTimeSpec(result));

  delta = Microseconds(Time::kMicrosecondsPerSecond   1);
  result = delta.ToTimeSpec();
  EXPECT_EQ(result.tv_sec, 1);
  EXPECT_EQ(result.tv_nsec, 1000);
  EXPECT_EQ(delta, TimeDelta::FromTimeSpec(result));
}
#endif  // BUILDFLAG(IS_POSIX) || BUILDFLAG(IS_FUCHSIA)

// Our internal time format is serialized in things like databases, so it's
// important that it's consistent across all our platforms.  We use the 1601
// Windows epoch as the internal format across all platforms.
TEST(TimeDelta, WindowsEpoch) {
  Time::Exploded exploded;
  exploded.year = 1970;
  exploded.month = 1;
  exploded.day_of_week = 0;  // Should be unusued.
  exploded.day_of_month = 1;
  exploded.hour = 0;
  exploded.minute = 0;
  exploded.second = 0;
  exploded.millisecond = 0;
  Time t;
  EXPECT_TRUE(Time::FromUTCExploded(exploded, &t));
  // Unix 1970 epoch.
  EXPECT_EQ(INT64_C(11644473600000000), t.ToInternalValue());

  // We can't test 1601 epoch, since the system time functions on Linux
  // only compute years starting from 1900.
}

TEST(TimeDelta, Hz) {
  static_assert(Hertz(1) == Seconds(1));
  EXPECT_EQ(Hertz(0), TimeDelta::Max());
  static_assert(Hertz(-1) == Seconds(-1));
  static_assert(Hertz(1000) == Milliseconds(1));
  static_assert(Hertz(0.5) == Seconds(2));
  static_assert(Hertz(std::numeric_limits<double>::infinity()) == TimeDelta(),
                "");

  static_assert(Seconds(1).ToHz() == 1);
  static_assert(TimeDelta::Max().ToHz() == 0);
  static_assert(Seconds(-1).ToHz() == -1);
  static_assert(Milliseconds(1).ToHz() == 1000);
  static_assert(Seconds(2).ToHz() == 0.5);
  EXPECT_EQ(TimeDelta().ToHz(), std::numeric_limits<double>::infinity());

  // 60 Hz can't be represented exactly.
  static_assert(Hertz(60) * 60 != Seconds(1));
  static_assert(Hertz(60).ToHz() != 60);
  EXPECT_EQ(base::ClampRound(Hertz(60).ToHz()), 60);
}

TEST(TimeDelta, Magnitude) {
  constexpr int64_t zero = 0;
  static_assert(Microseconds(zero) == Microseconds(zero).magnitude());

  constexpr int64_t one = 1;
  constexpr int64_t negative_one = -1;
  static_assert(Microseconds(one) == Microseconds(one).magnitude());
  static_assert(Microseconds(one) == Microseconds(negative_one).magnitude(),
                "");

  constexpr int64_t max_int64_minus_one =
      std::numeric_limits<int64_t>::max() - 1;
  constexpr int64_t min_int64_plus_two =
      std::numeric_limits<int64_t>::min()   2;
  static_assert(Microseconds(max_int64_minus_one) ==
                    Microseconds(max_int64_minus_one).magnitude(),
                "");
  static_assert(Microseconds(max_int64_minus_one) ==
                    Microseconds(min_int64_plus_two).magnitude(),
                "");

  static_assert(TimeDelta::Max() == TimeDelta::Min().magnitude());
}

TEST(TimeDelta, ZeroMinMax) {
  constexpr TimeDelta kZero;
  static_assert(kZero.is_zero());

  constexpr TimeDelta kMax = TimeDelta::Max();
  static_assert(kMax.is_max());
  static_assert(kMax == TimeDelta::Max());
  static_assert(kMax > Days(100 * 365));
  static_assert(kMax > kZero);

  constexpr TimeDelta kMin = TimeDelta::Min();
  static_assert(kMin.is_min());
  static_assert(kMin == TimeDelta::Min());
  static_assert(kMin < Days(-100 * 365));
  static_assert(kMin < kZero);
}

TEST(TimeDelta, MaxConversions) {
  // static_assert also confirms constexpr works as intended.
  constexpr TimeDelta kMax = TimeDelta::Max();
  static_assert(kMax.ToInternalValue() == std::numeric_limits<int64_t>::max(),
                "");
  static_assert(kMax.InDays() == std::numeric_limits<int>::max());
  static_assert(kMax.InHours() == std::numeric_limits<int>::max());
  static_assert(kMax.InMinutes() == std::numeric_limits<int>::max());
  static_assert(kMax.InSecondsF() == std::numeric_limits<double>::infinity(),
                "");
  static_assert(kMax.InSeconds() == std::numeric_limits<int64_t>::max());
  static_assert(kMax.InMillisecondsF() ==
                std::numeric_limits<double>::infinity());
  static_assert(kMax.InMilliseconds() == std::numeric_limits<int64_t>::max());
  static_assert(kMax.InMillisecondsRoundedUp() ==
                std::numeric_limits<int64_t>::max());

  static_assert(Days(std::numeric_limits<int64_t>::max()).is_max());

  static_assert(Hours(std::numeric_limits<int64_t>::max()).is_max());

  static_assert(Minutes(std::numeric_limits<int64_t>::max()).is_max());

  constexpr int64_t max_int = std::numeric_limits<int64_t>::max();
  constexpr int64_t min_int = std::numeric_limits<int64_t>::min();

  static_assert(Seconds(max_int / Time::kMicrosecondsPerSecond   1).is_max(),
                "");

  static_assert(
      Milliseconds(max_int / Time::kMillisecondsPerSecond   1).is_max(), "");

  static_assert(Microseconds(max_int).is_max());

  static_assert(Seconds(min_int / Time::kMicrosecondsPerSecond - 1).is_min(),
                "");

  static_assert(
      Milliseconds(min_int / Time::kMillisecondsPerSecond - 1).is_min(), "");

  static_assert(Microseconds(min_int).is_min());

  static_assert(Microseconds(std::numeric_limits<int64_t>::min()).is_min());

  static_assert(Seconds(std::numeric_limits<double>::infinity()).is_max());

  // Note that max_int/min_int will be rounded when converted to doubles - they
  // can't be exactly represented.
  constexpr double max_d = static_cast<double>(max_int);
  constexpr double min_d = static_cast<double>(min_int);

  static_assert(Seconds(max_d / Time::kMicrosecondsPerSecond   1).is_max());

  static_assert(
      Microseconds(max_d).is_max(),
      "Make sure that 2^63 correctly gets clamped to `max` (crbug.com/612601)");

  static_assert(Milliseconds(std::numeric_limits<double>::infinity()).is_max(),
                "");

  static_assert(Milliseconds(max_d / Time::kMillisecondsPerSecond * 2).is_max(),
                "");

  static_assert(Seconds(min_d / Time::kMicrosecondsPerSecond - 1).is_min());

  static_assert(Milliseconds(min_d / Time::kMillisecondsPerSecond * 2).is_min(),
                "");
}

TEST(TimeDelta, MinConversions) {
  constexpr TimeDelta kMin = TimeDelta::Min();

  static_assert(kMin.InDays() == std::numeric_limits<int>::min());
  static_assert(kMin.InHours() == std::numeric_limits<int>::min());
  static_assert(kMin.InMinutes() == std::numeric_limits<int>::min());
  static_assert(kMin.InSecondsF() == -std::numeric_limits<double>::infinity(),
                "");
  static_assert(kMin.InSeconds() == std::numeric_limits<int64_t>::min());
  static_assert(kMin.InMillisecondsF() ==
                -std::numeric_limits<double>::infinity());
  static_assert(kMin.InMilliseconds() == std::numeric_limits<int64_t>::min());
  static_assert(kMin.InMillisecondsRoundedUp() ==
                std::numeric_limits<int64_t>::min());
}

TEST(TimeDelta, FiniteMaxMin) {
  constexpr TimeDelta kFiniteMax = TimeDelta::FiniteMax();
  constexpr TimeDelta kUnit = Microseconds(1);
  static_assert(kFiniteMax   kUnit == TimeDelta::Max());
  static_assert(kFiniteMax - kUnit < kFiniteMax);

  constexpr TimeDelta kFiniteMin = TimeDelta::FiniteMin();
  static_assert(kFiniteMin - kUnit == TimeDelta::Min());
  static_assert(kFiniteMin   kUnit > kFiniteMin);
}

TEST(TimeDelta, NumericOperators) {
  constexpr double d = 0.5;
  static_assert(Milliseconds(500) == Milliseconds(1000) * d);
  static_assert(Milliseconds(2000) == (Milliseconds(1000) / d));
  static_assert(Milliseconds(500) == (Milliseconds(1000) *= d));
  static_assert(Milliseconds(2000) == (Milliseconds(1000) /= d));
  static_assert(Milliseconds(500) == d * Milliseconds(1000));

  constexpr float f = 0.5;
  static_assert(Milliseconds(500) == Milliseconds(1000) * f);
  static_assert(Milliseconds(2000) == (Milliseconds(1000) / f));
  static_assert(Milliseconds(500) == (Milliseconds(1000) *= f));
  static_assert(Milliseconds(2000) == (Milliseconds(1000) /= f));
  static_assert(Milliseconds(500) == f * Milliseconds(1000));

  constexpr int i = 2;
  static_assert(Milliseconds(2000) == Milliseconds(1000) * i);
  static_assert(Milliseconds(500) == (Milliseconds(1000) / i));
  static_assert(Milliseconds(2000) == (Milliseconds(1000) *= i));
  static_assert(Milliseconds(500) == (Milliseconds(1000) /= i));
  static_assert(Milliseconds(2000) == i * Milliseconds(1000));

  constexpr int64_t i64 = 2;
  static_assert(Milliseconds(2000) == Milliseconds(1000) * i64);
  static_assert(Milliseconds(500) == (Milliseconds(1000) / i64));
  static_assert(Milliseconds(2000) == (Milliseconds(1000) *= i64));
  static_assert(Milliseconds(500) == (Milliseconds(1000) /= i64));
  static_assert(Milliseconds(2000) == i64 * Milliseconds(1000));

  static_assert(Milliseconds(500) == Milliseconds(1000) * 0.5);
  static_assert(Milliseconds(2000) == (Milliseconds(1000) / 0.5));
  static_assert(Milliseconds(500) == (Milliseconds(1000) *= 0.5));
  static_assert(Milliseconds(2000) == (Milliseconds(1000) /= 0.5));
  static_assert(Milliseconds(500) == 0.5 * Milliseconds(1000));

  static_assert(Milliseconds(2000) == Milliseconds(1000) * 2);
  static_assert(Milliseconds(500) == (Milliseconds(1000) / 2));
  static_assert(Milliseconds(2000) == (Milliseconds(1000) *= 2));
  static_assert(Milliseconds(500) == (Milliseconds(1000) /= 2));
  static_assert(Milliseconds(2000) == 2 * Milliseconds(1000));
}

// Basic test of operators between TimeDeltas (without overflow -- next test
// handles overflow).
TEST(TimeDelta, TimeDeltaOperators) {
  constexpr TimeDelta kElevenSeconds = Seconds(11);
  constexpr TimeDelta kThreeSeconds = Seconds(3);

  static_assert(Seconds(14) == kElevenSeconds   kThreeSeconds);
  static_assert(Seconds(14) == kThreeSeconds   kElevenSeconds);
  static_assert(Seconds(8) == kElevenSeconds - kThreeSeconds);
  static_assert(Seconds(-8) == kThreeSeconds - kElevenSeconds);
  static_assert(11.0 / 3.0 == kElevenSeconds / kThreeSeconds);
  static_assert(3.0 / 11.0 == kThreeSeconds / kElevenSeconds);
  static_assert(3 == kElevenSeconds.IntDiv(kThreeSeconds));
  static_assert(0 == kThreeSeconds.IntDiv(kElevenSeconds));
  static_assert(Seconds(2) == kElevenSeconds % kThreeSeconds);
}

TEST(TimeDelta, Overflows) {
  // Some sanity checks. static_asserts used where possible to verify constexpr
  // evaluation at the same time.
  static_assert(TimeDelta::Max().is_max());
  static_assert(TimeDelta::Max().is_positive());
  static_assert((-TimeDelta::Max()).is_negative());
  static_assert(-TimeDelta::Max() == TimeDelta::Min());
  static_assert(TimeDelta() > -TimeDelta::Max());

  static_assert(TimeDelta::Min().is_min());
  static_assert(TimeDelta::Min().is_negative());
  static_assert((-TimeDelta::Min()).is_positive());
  static_assert(-TimeDelta::Min() == TimeDelta::Max());
  static_assert(TimeDelta() < -TimeDelta::Min());

  constexpr TimeDelta kLargeDelta = TimeDelta::Max() - Milliseconds(1);
  constexpr TimeDelta kLargeNegative = -kLargeDelta;
  static_assert(TimeDelta() > kLargeNegative);
  static_assert(!kLargeDelta.is_max());
  static_assert(!(-kLargeNegative).is_min());

  // Test  , -, * and / operators.
  constexpr TimeDelta kOneSecond = Seconds(1);
  static_assert((kLargeDelta   kOneSecond).is_max());
  static_assert((kLargeNegative   (-kOneSecond)).is_min());
  static_assert((kLargeNegative - kOneSecond).is_min());
  static_assert((kLargeDelta - (-kOneSecond)).is_max());
  static_assert((kLargeDelta * 2).is_max());
  static_assert((kLargeDelta * -2).is_min());
  static_assert((kLargeDelta / 0.5).is_max());
  static_assert((kLargeDelta / -0.5).is_min());

  // Test math operators on Max() and Min() values
  // Calculations that would overflow are saturated.
  static_assert(TimeDelta::Max()   kOneSecond == TimeDelta::Max());
  static_assert(TimeDelta::Max() * 7 == TimeDelta::Max());
  static_assert(TimeDelta::FiniteMax()   kOneSecond == TimeDelta::Max());
  static_assert(TimeDelta::Min() - kOneSecond == TimeDelta::Min());
  static_assert(TimeDelta::Min() * 7 == TimeDelta::Min());
  static_assert(TimeDelta::FiniteMin() - kOneSecond == TimeDelta::Min());

  // Division is done by converting to double with Max()/Min() converted to
  //  /- infinities.
  static_assert(
      TimeDelta::Max() / kOneSecond == std::numeric_limits<double>::infinity(),
      "");
  static_assert(TimeDelta::Max() / -kOneSecond ==
                    -std::numeric_limits<double>::infinity(),
                "");
  static_assert(
      TimeDelta::Min() / kOneSecond == -std::numeric_limits<double>::infinity(),
      "");
  static_assert(
      TimeDelta::Min() / -kOneSecond == std::numeric_limits<double>::infinity(),
      "");
  static_assert(TimeDelta::Max().IntDiv(kOneSecond) ==
                    std::numeric_limits<int64_t>::max(),
                "");
  static_assert(TimeDelta::Max().IntDiv(-kOneSecond) ==
                    std::numeric_limits<int64_t>::min(),
                "");
  static_assert(TimeDelta::Min().IntDiv(kOneSecond) ==
                    std::numeric_limits<int64_t>::min(),
                "");
  static_assert(TimeDelta::Min().IntDiv(-kOneSecond) ==
                    std::numeric_limits<int64_t>::max(),
                "");
  static_assert(TimeDelta::Max() % kOneSecond == TimeDelta::Max());
  static_assert(TimeDelta::Max() % -kOneSecond == TimeDelta::Max());
  static_assert(TimeDelta::Min() % kOneSecond == TimeDelta::Min());
  static_assert(TimeDelta::Min() % -kOneSecond == TimeDelta::Min());

  // Division by zero.
  static_assert((kOneSecond / 0).is_max());
  static_assert((-kOneSecond / 0).is_min());
  static_assert((TimeDelta::Max() / 0).is_max());
  static_assert((TimeDelta::Min() / 0).is_min());
  EXPECT_EQ(std::numeric_limits<double>::infinity(), kOneSecond / TimeDelta());
  EXPECT_EQ(-std::numeric_limits<double>::infinity(),
            -kOneSecond / TimeDelta());
  EXPECT_EQ(std::numeric_limits<double>::infinity(),
            TimeDelta::Max() / TimeDelta());
  EXPECT_EQ(-std::numeric_limits<double>::infinity(),
            TimeDelta::Min() / TimeDelta());
  static_assert(
      kOneSecond.IntDiv(TimeDelta()) == std::numeric_limits<int64_t>::max(),
      "");
  static_assert(
      (-kOneSecond).IntDiv(TimeDelta()) == std::numeric_limits<int64_t>::min(),
      "");
  static_assert(TimeDelta::Max().IntDiv(TimeDelta()) ==
                    std::numeric_limits<int64_t>::max(),
                "");
  static_assert(TimeDelta::Min().IntDiv(TimeDelta()) ==
                    std::numeric_limits<int64_t>::min(),
                "");
  static_assert(kOneSecond % TimeDelta() == kOneSecond);
  static_assert(-kOneSecond % TimeDelta() == -kOneSecond);
  static_assert(TimeDelta::Max() % TimeDelta() == TimeDelta::Max());
  static_assert(TimeDelta::Min() % TimeDelta() == TimeDelta::Min());

  // Division by infinity.
  static_assert(kLargeDelta / TimeDelta::Min() == 0);
  static_assert(kLargeDelta / TimeDelta::Max() == 0);
  static_assert(kLargeNegative / TimeDelta::Min() == 0);
  static_assert(kLargeNegative / TimeDelta::Max() == 0);
  static_assert(kLargeDelta.IntDiv(TimeDelta::Min()) == 0);
  static_assert(kLargeDelta.IntDiv(TimeDelta::Max()) == 0);
  static_assert(kLargeNegative.IntDiv(TimeDelta::Min()) == 0);
  static_assert(kLargeNegative.IntDiv(TimeDelta::Max()) == 0);
  static_assert(kOneSecond % TimeDelta::Min() == kOneSecond);
  static_assert(kOneSecond % TimeDelta::Max() == kOneSecond);

  // Test that double conversions overflow to infinity.
  static_assert((kLargeDelta   kOneSecond).InSecondsF() ==
                    std::numeric_limits<double>::infinity(),
                "");
  static_assert((kLargeDelta   kOneSecond).InMillisecondsF() ==
                std::numeric_limits<double>::infinity());
  static_assert((kLargeDelta   kOneSecond).InMicrosecondsF() ==
                std::numeric_limits<double>::infinity());

  // Test op=.
  static_assert((TimeDelta::FiniteMax()  = kOneSecond).is_max());
  static_assert((TimeDelta::FiniteMin()  = -kOneSecond).is_min());

  static_assert((TimeDelta::FiniteMin() -= kOneSecond).is_min());
  static_assert((TimeDelta::FiniteMax() -= -kOneSecond).is_max());

  static_assert((TimeDelta::FiniteMax() *= 2).is_max());
  static_assert((TimeDelta::FiniteMin() *= 1.5).is_min());

  static_assert((TimeDelta::FiniteMax() /= 0.5).is_max());
  static_assert((TimeDelta::FiniteMin() /= 0.5).is_min());

  static_assert((Seconds(1) %= TimeDelta::Max()) == Seconds(1));
  static_assert((Seconds(1) %= TimeDelta()) == Seconds(1));

  // Test operations with Time and TimeTicks.
  EXPECT_TRUE((kLargeDelta   Time::Now()).is_max());
  EXPECT_TRUE((kLargeDelta   TimeTicks::Now()).is_max());
  EXPECT_TRUE((Time::Now()   kLargeDelta).is_max());
  EXPECT_TRUE((TimeTicks::Now()   kLargeDelta).is_max());

  Time time_now = Time::Now();
  EXPECT_EQ(kOneSecond, (time_now   kOneSecond) - time_now);
  EXPECT_EQ(-kOneSecond, (time_now - kOneSecond) - time_now);

  TimeTicks ticks_now = TimeTicks::Now();
  EXPECT_EQ(-kOneSecond, (ticks_now - kOneSecond) - ticks_now);
  EXPECT_EQ(kOneSecond, (ticks_now   kOneSecond) - ticks_now);
}

TEST(TimeDelta, CeilToMultiple) {
  for (const auto interval : {Seconds(10), Seconds(-10)}) {
    SCOPED_TRACE(interval);
    EXPECT_EQ(TimeDelta().CeilToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(1).CeilToMultiple(interval), Seconds(10));
    EXPECT_EQ(Seconds(9).CeilToMultiple(interval), Seconds(10));
    EXPECT_EQ(Seconds(10).CeilToMultiple(interval), Seconds(10));
    EXPECT_EQ(Seconds(15).CeilToMultiple(interval), Seconds(20));
    EXPECT_EQ(Seconds(20).CeilToMultiple(interval), Seconds(20));
    EXPECT_EQ(TimeDelta::Max().CeilToMultiple(interval), TimeDelta::Max());
    EXPECT_EQ(Seconds(-1).CeilToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(-9).CeilToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(-10).CeilToMultiple(interval), Seconds(-10));
    EXPECT_EQ(Seconds(-15).CeilToMultiple(interval), Seconds(-10));
    EXPECT_EQ(Seconds(-20).CeilToMultiple(interval), Seconds(-20));
    EXPECT_EQ(TimeDelta::Min().CeilToMultiple(interval), TimeDelta::Min());
  }

  for (const auto interval : {TimeDelta::Max(), TimeDelta::Min()}) {
    SCOPED_TRACE(interval);
    EXPECT_EQ(TimeDelta().CeilToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(1).CeilToMultiple(interval), TimeDelta::Max());
    EXPECT_EQ(Seconds(9).CeilToMultiple(interval), TimeDelta::Max());
    EXPECT_EQ(Seconds(10).CeilToMultiple(interval), TimeDelta::Max());
    EXPECT_EQ(Seconds(15).CeilToMultiple(interval), TimeDelta::Max());
    EXPECT_EQ(Seconds(20).CeilToMultiple(interval), TimeDelta::Max());
    EXPECT_EQ(TimeDelta::Max().CeilToMultiple(interval), TimeDelta::Max());
    EXPECT_EQ(Seconds(-1).CeilToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(-9).CeilToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(-10).CeilToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(-15).CeilToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(-20).CeilToMultiple(interval), TimeDelta());
    EXPECT_EQ(TimeDelta::Min().CeilToMultiple(interval), TimeDelta::Min());
  }
}

TEST(TimeDelta, FloorToMultiple) {
  for (const auto interval : {Seconds(10), Seconds(-10)}) {
    SCOPED_TRACE(interval);
    EXPECT_EQ(TimeDelta().FloorToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(1).FloorToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(9).FloorToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(10).FloorToMultiple(interval), Seconds(10));
    EXPECT_EQ(Seconds(15).FloorToMultiple(interval), Seconds(10));
    EXPECT_EQ(Seconds(20).FloorToMultiple(interval), Seconds(20));
    EXPECT_EQ(TimeDelta::Max().FloorToMultiple(interval), TimeDelta::Max());
    EXPECT_EQ(Seconds(-1).FloorToMultiple(interval), Seconds(-10));
    EXPECT_EQ(Seconds(-9).FloorToMultiple(interval), Seconds(-10));
    EXPECT_EQ(Seconds(-10).FloorToMultiple(interval), Seconds(-10));
    EXPECT_EQ(Seconds(-15).FloorToMultiple(interval), Seconds(-20));
    EXPECT_EQ(Seconds(-20).FloorToMultiple(interval), Seconds(-20));
    EXPECT_EQ(TimeDelta::Min().FloorToMultiple(interval), TimeDelta::Min());
  }

  for (const auto interval : {TimeDelta::Max(), TimeDelta::Min()}) {
    SCOPED_TRACE(interval);
    EXPECT_EQ(TimeDelta().FloorToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(1).FloorToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(9).FloorToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(10).FloorToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(15).FloorToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(20).FloorToMultiple(interval), TimeDelta());
    EXPECT_EQ(TimeDelta::Max().FloorToMultiple(interval), TimeDelta::Max());
    EXPECT_EQ(Seconds(-1).FloorToMultiple(interval), TimeDelta::Min());
    EXPECT_EQ(Seconds(-9).FloorToMultiple(interval), TimeDelta::Min());
    EXPECT_EQ(Seconds(-10).FloorToMultiple(interval), TimeDelta::Min());
    EXPECT_EQ(Seconds(-15).FloorToMultiple(interval), TimeDelta::Min());
    EXPECT_EQ(Seconds(-20).FloorToMultiple(interval), TimeDelta::Min());
    EXPECT_EQ(TimeDelta::Min().FloorToMultiple(interval), TimeDelta::Min());
  }
}

TEST(TimeDelta, RoundToMultiple) {
  for (const auto interval : {Seconds(10), Seconds(-10)}) {
    SCOPED_TRACE(interval);
    EXPECT_EQ(TimeDelta().RoundToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(1).RoundToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(9).RoundToMultiple(interval), Seconds(10));
    EXPECT_EQ(Seconds(10).RoundToMultiple(interval), Seconds(10));
    EXPECT_EQ(Seconds(15).RoundToMultiple(interval), Seconds(20));
    EXPECT_EQ(Seconds(20).RoundToMultiple(interval), Seconds(20));
    EXPECT_EQ(TimeDelta::Max().RoundToMultiple(interval), TimeDelta::Max());
    EXPECT_EQ(Seconds(-1).RoundToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(-9).RoundToMultiple(interval), Seconds(-10));
    EXPECT_EQ(Seconds(-10).RoundToMultiple(interval), Seconds(-10));
    EXPECT_EQ(Seconds(-15).RoundToMultiple(interval), Seconds(-20));
    EXPECT_EQ(Seconds(-20).RoundToMultiple(interval), Seconds(-20));
    EXPECT_EQ(TimeDelta::Min().RoundToMultiple(interval), TimeDelta::Min());
  }

  for (const auto interval : {TimeDelta::Max(), TimeDelta::Min()}) {
    SCOPED_TRACE(interval);
    EXPECT_EQ(TimeDelta().RoundToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(1).RoundToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(9).RoundToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(10).RoundToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(15).RoundToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(20).RoundToMultiple(interval), TimeDelta());
    EXPECT_EQ(TimeDelta::Max().RoundToMultiple(interval), TimeDelta::Max());
    EXPECT_EQ(Seconds(-1).RoundToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(-9).RoundToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(-10).RoundToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(-15).RoundToMultiple(interval), TimeDelta());
    EXPECT_EQ(Seconds(-20).RoundToMultiple(interval), TimeDelta());
    EXPECT_EQ(TimeDelta::Min().RoundToMultiple(interval), TimeDelta::Min());
  }
}

TEST(TimeBase, AddSubDeltaSaturates) {
  constexpr TimeTicks kLargeTimeTicks =
      TimeTicks::FromInternalValue(std::numeric_limits<int64_t>::max() - 1);

  constexpr TimeTicks kLargeNegativeTimeTicks =
      TimeTicks::FromInternalValue(std::numeric_limits<int64_t>::min()   1);

  static_assert((kLargeTimeTicks   TimeDelta::Max()).is_max());
  static_assert((kLargeNegativeTimeTicks   TimeDelta::Max()).is_max());
  static_assert((kLargeTimeTicks - TimeDelta::Max()).is_min());
  static_assert((kLargeNegativeTimeTicks - TimeDelta::Max()).is_min());
  static_assert((TimeTicks()   TimeDelta::Max()).is_max());
  static_assert((TimeTicks() - TimeDelta::Max()).is_min());
  EXPECT_TRUE((TimeTicks::Now()   TimeDelta::Max()).is_max())
      << (TimeTicks::Now()   TimeDelta::Max());
  EXPECT_TRUE((TimeTicks::Now() - TimeDelta::Max()).is_min())
      << (TimeTicks::Now() - TimeDelta::Max());

  static_assert((kLargeTimeTicks   TimeDelta::Min()).is_min());
  static_assert((kLargeNegativeTimeTicks   TimeDelta::Min()).is_min());
  static_assert((kLargeTimeTicks - TimeDelta::Min()).is_max());
  static_assert((kLargeNegativeTimeTicks - TimeDelta::Min()).is_max());
  static_assert((TimeTicks()   TimeDelta::Min()).is_min());
  static_assert((TimeTicks() - TimeDelta::Min()).is_max());
  EXPECT_TRUE((TimeTicks::Now()   TimeDelta::Min()).is_min())
      << (TimeTicks::Now()   TimeDelta::Min());
  EXPECT_TRUE((TimeTicks::Now() - TimeDelta::Min()).is_max())
      << (TimeTicks::Now() - TimeDelta::Min());
}

TEST(TimeBase, AddSubInfinities) {
  // CHECK when adding opposite signs or subtracting same sign.
  EXPECT_CHECK_DEATH({ TimeTicks::Min()   TimeDelta::Max(); });
  EXPECT_CHECK_DEATH({ TimeTicks::Max()   TimeDelta::Min(); });
  EXPECT_CHECK_DEATH({ TimeTicks::Min() - TimeDelta::Min(); });
  EXPECT_CHECK_DEATH({ TimeTicks::Max() - TimeDelta::Max(); });

  // Saturates when adding same sign or subtracting opposite signs.
  static_assert((TimeTicks::Max()   TimeDelta::Max()).is_max());
  static_assert((TimeTicks::Min()   TimeDelta::Min()).is_min());
  static_assert((TimeTicks::Max() - TimeDelta::Min()).is_max());
  static_assert((TimeTicks::Min() - TimeDelta::Max()).is_min());
}

constexpr TimeTicks TestTimeTicksConstexprCopyAssignment() {
  TimeTicks a = TimeTicks::FromInternalValue(12345);
  TimeTicks b;
  b = a;
  return b;
}

TEST(TimeTicks, ConstexprAndTriviallyCopiable) {
  // "Trivially copyable" is necessary for use in std::atomic<TimeTicks>.
  static_assert(std::is_trivially_copyable<TimeTicks>());

  // Copy ctor.
  constexpr TimeTicks a = TimeTicks::FromInternalValue(12345);
  constexpr TimeTicks b{a};
  static_assert(a.ToInternalValue() == b.ToInternalValue());

  // Copy assignment.
  static_assert(a.ToInternalValue() ==
                    TestTimeTicksConstexprCopyAssignment().ToInternalValue(),
                "");
}

constexpr ThreadTicks TestThreadTicksConstexprCopyAssignment() {
  ThreadTicks a = ThreadTicks::FromInternalValue(12345);
  ThreadTicks b;
  b = a;
  return b;
}

TEST(ThreadTicks, ConstexprAndTriviallyCopiable) {
  // "Trivially copyable" is necessary for use in std::atomic<ThreadTicks>.
  static_assert(std::is_trivially_copyable<ThreadTicks>());

  // Copy ctor.
  constexpr ThreadTicks a = ThreadTicks::FromInternalValue(12345);
  constexpr ThreadTicks b{a};
  static_assert(a.ToInternalValue() == b.ToInternalValue());

  // Copy assignment.
  static_assert(a.ToInternalValue() ==
                    TestThreadTicksConstexprCopyAssignment().ToInternalValue(),
                "");
}

constexpr TimeDelta TestTimeDeltaConstexprCopyAssignment() {
  TimeDelta a = Seconds(1);
  TimeDelta b;
  b = a;
  return b;
}

TEST(TimeDelta, ConstexprAndTriviallyCopiable) {
  // "Trivially copyable" is necessary for use in std::atomic<TimeDelta>.
  static_assert(std::is_trivially_copyable<TimeDelta>());

  // Copy ctor.
  constexpr TimeDelta a = Seconds(1);
  constexpr TimeDelta b{a};
  static_assert(a == b);

  // Copy assignment.
  static_assert(a == TestTimeDeltaConstexprCopyAssignment());
}

TEST(TimeDeltaLogging, DCheckEqCompiles) {
  DCHECK_EQ(TimeDelta(), TimeDelta());
}

TEST(TimeDeltaLogging, EmptyIsZero) {
  constexpr TimeDelta kZero;
  EXPECT_EQ("0 s", ToString(kZero));
}

TEST(TimeDeltaLogging, FiveHundredMs) {
  constexpr TimeDelta kFiveHundredMs = Milliseconds(500);
  EXPECT_EQ("0.5 s", ToString(kFiveHundredMs));
}

TEST(TimeDeltaLogging, MinusTenSeconds) {
  constexpr TimeDelta kMinusTenSeconds = Seconds(-10);
  EXPECT_EQ("-10 s", ToString(kMinusTenSeconds));
}

TEST(TimeDeltaLogging, DoesNotMessUpFormattingFlags) {
  std::ostringstream oss;
  std::ios_base::fmtflags flags_before = oss.flags();
  oss << TimeDelta();
  EXPECT_EQ(flags_before, oss.flags());
}

TEST(TimeDeltaLogging, DoesNotMakeStreamBad) {
  std::ostringstream oss;
  oss << TimeDelta();
  EXPECT_TRUE(oss.good());
}

TEST(TimeLogging, DCheckEqCompiles) {
  DCHECK_EQ(Time(), Time());
}

TEST(TimeLogging, ChromeBirthdate) {
  Time birthdate;
  ASSERT_TRUE(Time::FromString("Tue, 02 Sep 2008 09:42:18 GMT", &birthdate));
  EXPECT_EQ("2008-09-02 09:42:18.000000 UTC", ToString(birthdate));
}

TEST(TimeLogging, Microseconds) {
  // Some Time with a non-zero number of microseconds.
  Time now = Time::Now();
  if (now.ToDeltaSinceWindowsEpoch().InMicroseconds() %
          Time::kMicrosecondsPerMillisecond ==
      0) {
    now  = Microseconds(1);
  }

  // Crudely parse the microseconds portion out of the stringified Time. Use
  // find() and ASSERTs to try to give an accurate test result, without
  // crashing, even if the logging format changes in the future (e.g. someone
  // removes microseconds, adds nanoseconds, changes the timezone format, etc.).
  const std::string now_str = ToString(now);
  ASSERT_GT(now_str.length(), 6u);
  const size_t period = now_str.find('.');
  ASSERT_LT(period, now_str.length() - 6);
  int microseconds = 0;
  EXPECT_TRUE(StringToInt(now_str.substr(period   4, 3), &microseconds));

  // The stringified microseconds should also be nonzero.
  EXPECT_NE(0, microseconds);
}

TEST(TimeLogging, DoesNotMessUpFormattingFlags) {
  std::ostringstream oss;
  std::ios_base::fmtflags flags_before = oss.flags();
  oss << Time();
  EXPECT_EQ(flags_before, oss.flags());
}

TEST(TimeLogging, DoesNotMakeStreamBad) {
  std::ostringstream oss;
  oss << Time();
  EXPECT_TRUE(oss.good());
}

TEST(TimeTicksLogging, DCheckEqCompiles) {
  DCHECK_EQ(TimeTicks(), TimeTicks());
}

TEST(TimeTicksLogging, ZeroTime) {
  TimeTicks zero;
  EXPECT_EQ("0 bogo-microseconds", ToString(zero));
}

TEST(TimeTicksLogging, FortyYearsLater) {
  TimeTicks forty_years_later = TimeTicks()   Days(365.25 * 40);
  EXPECT_EQ("1262304000000000 bogo-microseconds", ToString(forty_years_later));
}

TEST(TimeTicksLogging, DoesNotMessUpFormattingFlags) {
  std::ostringstream oss;
  std::ios_base::fmtflags flags_before = oss.flags();
  oss << TimeTicks();
  EXPECT_EQ(flags_before, oss.flags());
}

TEST(TimeTicksLogging, DoesNotMakeStreamBad) {
  std::ostringstream oss;
  oss << TimeTicks();
  EXPECT_TRUE(oss.good());
}

}  // namespace

}  // namespace base