xref: /aosp_15_r20/external/abseil-cpp/absl/time/time_test.cc (revision 9356374a3709195abf420251b3e825997ff56c0f)
1 // Copyright 2017 The Abseil Authors.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 //      https://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 
15 #include "absl/time/time.h"
16 
17 #include <cstdint>
18 #include <ios>
19 
20 #include "absl/time/civil_time.h"
21 
22 #if defined(_MSC_VER)
23 #include <winsock2.h>  // for timeval
24 #endif
25 
26 #include <chrono>  // NOLINT(build/c++11)
27 
28 #ifdef __cpp_impl_three_way_comparison
29 #include <compare>
30 #endif  // __cpp_impl_three_way_comparison
31 
32 #include <cstring>
33 #include <ctime>
34 #include <iomanip>
35 #include <limits>
36 #include <string>
37 
38 #include "gmock/gmock.h"
39 #include "gtest/gtest.h"
40 #include "absl/numeric/int128.h"
41 #include "absl/strings/str_format.h"
42 #include "absl/time/clock.h"
43 #include "absl/time/internal/test_util.h"
44 
45 namespace {
46 
47 #if defined(GTEST_USES_SIMPLE_RE) && GTEST_USES_SIMPLE_RE
48 const char kZoneAbbrRE[] = ".*";  // just punt
49 #else
50 const char kZoneAbbrRE[] = "[A-Za-z]{3,4}|[-+][0-9]{2}([0-9]{2})?";
51 #endif
52 
53 // This helper is a macro so that failed expectations show up with the
54 // correct line numbers.
55 #define EXPECT_CIVIL_INFO(ci, y, m, d, h, min, s, off, isdst)      \
56   do {                                                             \
57     EXPECT_EQ(y, ci.cs.year());                                    \
58     EXPECT_EQ(m, ci.cs.month());                                   \
59     EXPECT_EQ(d, ci.cs.day());                                     \
60     EXPECT_EQ(h, ci.cs.hour());                                    \
61     EXPECT_EQ(min, ci.cs.minute());                                \
62     EXPECT_EQ(s, ci.cs.second());                                  \
63     EXPECT_EQ(off, ci.offset);                                     \
64     EXPECT_EQ(isdst, ci.is_dst);                                   \
65     EXPECT_THAT(ci.zone_abbr, testing::MatchesRegex(kZoneAbbrRE)); \
66   } while (0)
67 
68 // A gMock matcher to match timespec values. Use this matcher like:
69 // timespec ts1, ts2;
70 // EXPECT_THAT(ts1, TimespecMatcher(ts2));
71 MATCHER_P(TimespecMatcher, ts, "") {
72   if (ts.tv_sec == arg.tv_sec && ts.tv_nsec == arg.tv_nsec) return true;
73   *result_listener << "expected: {" << ts.tv_sec << ", " << ts.tv_nsec << "} ";
74   *result_listener << "actual: {" << arg.tv_sec << ", " << arg.tv_nsec << "}";
75   return false;
76 }
77 
78 // A gMock matcher to match timeval values. Use this matcher like:
79 // timeval tv1, tv2;
80 // EXPECT_THAT(tv1, TimevalMatcher(tv2));
81 MATCHER_P(TimevalMatcher, tv, "") {
82   if (tv.tv_sec == arg.tv_sec && tv.tv_usec == arg.tv_usec) return true;
83   *result_listener << "expected: {" << tv.tv_sec << ", " << tv.tv_usec << "} ";
84   *result_listener << "actual: {" << arg.tv_sec << ", " << arg.tv_usec << "}";
85   return false;
86 }
87 
TEST(Time,ConstExpr)88 TEST(Time, ConstExpr) {
89   constexpr absl::Time t0 = absl::UnixEpoch();
90   static_assert(t0 == absl::UnixEpoch(), "UnixEpoch");
91   constexpr absl::Time t1 = absl::InfiniteFuture();
92   static_assert(t1 != absl::UnixEpoch(), "InfiniteFuture");
93   constexpr absl::Time t2 = absl::InfinitePast();
94   static_assert(t2 != absl::UnixEpoch(), "InfinitePast");
95   constexpr absl::Time t3 = absl::FromUnixNanos(0);
96   static_assert(t3 == absl::UnixEpoch(), "FromUnixNanos");
97   constexpr absl::Time t4 = absl::FromUnixMicros(0);
98   static_assert(t4 == absl::UnixEpoch(), "FromUnixMicros");
99   constexpr absl::Time t5 = absl::FromUnixMillis(0);
100   static_assert(t5 == absl::UnixEpoch(), "FromUnixMillis");
101   constexpr absl::Time t6 = absl::FromUnixSeconds(0);
102   static_assert(t6 == absl::UnixEpoch(), "FromUnixSeconds");
103   constexpr absl::Time t7 = absl::FromTimeT(0);
104   static_assert(t7 == absl::UnixEpoch(), "FromTimeT");
105 }
106 
TEST(Time,ValueSemantics)107 TEST(Time, ValueSemantics) {
108   absl::Time a;      // Default construction
109   absl::Time b = a;  // Copy construction
110   EXPECT_EQ(a, b);
111   absl::Time c(a);  // Copy construction (again)
112   EXPECT_EQ(a, b);
113   EXPECT_EQ(a, c);
114   EXPECT_EQ(b, c);
115   b = c;  // Assignment
116   EXPECT_EQ(a, b);
117   EXPECT_EQ(a, c);
118   EXPECT_EQ(b, c);
119 }
120 
TEST(Time,UnixEpoch)121 TEST(Time, UnixEpoch) {
122   const auto ci = absl::UTCTimeZone().At(absl::UnixEpoch());
123   EXPECT_EQ(absl::CivilSecond(1970, 1, 1, 0, 0, 0), ci.cs);
124   EXPECT_EQ(absl::ZeroDuration(), ci.subsecond);
125   EXPECT_EQ(absl::Weekday::thursday, absl::GetWeekday(ci.cs));
126 }
127 
TEST(Time,Breakdown)128 TEST(Time, Breakdown) {
129   absl::TimeZone tz = absl::time_internal::LoadTimeZone("America/New_York");
130   absl::Time t = absl::UnixEpoch();
131 
132   // The Unix epoch as seen in NYC.
133   auto ci = tz.At(t);
134   EXPECT_CIVIL_INFO(ci, 1969, 12, 31, 19, 0, 0, -18000, false);
135   EXPECT_EQ(absl::ZeroDuration(), ci.subsecond);
136   EXPECT_EQ(absl::Weekday::wednesday, absl::GetWeekday(ci.cs));
137 
138   // Just before the epoch.
139   t -= absl::Nanoseconds(1);
140   ci = tz.At(t);
141   EXPECT_CIVIL_INFO(ci, 1969, 12, 31, 18, 59, 59, -18000, false);
142   EXPECT_EQ(absl::Nanoseconds(999999999), ci.subsecond);
143   EXPECT_EQ(absl::Weekday::wednesday, absl::GetWeekday(ci.cs));
144 
145   // Some time later.
146   t += absl::Hours(24) * 2735;
147   t += absl::Hours(18) + absl::Minutes(30) + absl::Seconds(15) +
148        absl::Nanoseconds(9);
149   ci = tz.At(t);
150   EXPECT_CIVIL_INFO(ci, 1977, 6, 28, 14, 30, 15, -14400, true);
151   EXPECT_EQ(8, ci.subsecond / absl::Nanoseconds(1));
152   EXPECT_EQ(absl::Weekday::tuesday, absl::GetWeekday(ci.cs));
153 }
154 
TEST(Time,AdditiveOperators)155 TEST(Time, AdditiveOperators) {
156   const absl::Duration d = absl::Nanoseconds(1);
157   const absl::Time t0;
158   const absl::Time t1 = t0 + d;
159 
160   EXPECT_EQ(d, t1 - t0);
161   EXPECT_EQ(-d, t0 - t1);
162   EXPECT_EQ(t0, t1 - d);
163 
164   absl::Time t(t0);
165   EXPECT_EQ(t0, t);
166   t += d;
167   EXPECT_EQ(t0 + d, t);
168   EXPECT_EQ(d, t - t0);
169   t -= d;
170   EXPECT_EQ(t0, t);
171 
172   // Tests overflow between subseconds and seconds.
173   t = absl::UnixEpoch();
174   t += absl::Milliseconds(500);
175   EXPECT_EQ(absl::UnixEpoch() + absl::Milliseconds(500), t);
176   t += absl::Milliseconds(600);
177   EXPECT_EQ(absl::UnixEpoch() + absl::Milliseconds(1100), t);
178   t -= absl::Milliseconds(600);
179   EXPECT_EQ(absl::UnixEpoch() + absl::Milliseconds(500), t);
180   t -= absl::Milliseconds(500);
181   EXPECT_EQ(absl::UnixEpoch(), t);
182 }
183 
TEST(Time,RelationalOperators)184 TEST(Time, RelationalOperators) {
185   constexpr absl::Time t1 = absl::FromUnixNanos(0);
186   constexpr absl::Time t2 = absl::FromUnixNanos(1);
187   constexpr absl::Time t3 = absl::FromUnixNanos(2);
188 
189   static_assert(absl::UnixEpoch() == t1, "");
190   static_assert(t1 == t1, "");
191   static_assert(t2 == t2, "");
192   static_assert(t3 == t3, "");
193 
194   static_assert(t1 < t2, "");
195   static_assert(t2 < t3, "");
196   static_assert(t1 < t3, "");
197 
198   static_assert(t1 <= t1, "");
199   static_assert(t1 <= t2, "");
200   static_assert(t2 <= t2, "");
201   static_assert(t2 <= t3, "");
202   static_assert(t3 <= t3, "");
203   static_assert(t1 <= t3, "");
204 
205   static_assert(t2 > t1, "");
206   static_assert(t3 > t2, "");
207   static_assert(t3 > t1, "");
208 
209   static_assert(t2 >= t2, "");
210   static_assert(t2 >= t1, "");
211   static_assert(t3 >= t3, "");
212   static_assert(t3 >= t2, "");
213   static_assert(t1 >= t1, "");
214   static_assert(t3 >= t1, "");
215 
216 #ifdef __cpp_impl_three_way_comparison
217 
218   static_assert((t1 <=> t1) == std::strong_ordering::equal, "");
219   static_assert((t2 <=> t2) == std::strong_ordering::equal, "");
220   static_assert((t3 <=> t3) == std::strong_ordering::equal, "");
221 
222   static_assert((t1 <=> t2) == std::strong_ordering::less, "");
223   static_assert((t2 <=> t3) == std::strong_ordering::less, "");
224   static_assert((t1 <=> t3) == std::strong_ordering::less, "");
225 
226   static_assert((t2 <=> t1) == std::strong_ordering::greater, "");
227   static_assert((t3 <=> t2) == std::strong_ordering::greater, "");
228   static_assert((t3 <=> t1) == std::strong_ordering::greater, "");
229 
230 #endif  // __cpp_impl_three_way_comparison
231 }
232 
TEST(Time,Infinity)233 TEST(Time, Infinity) {
234   constexpr absl::Time ifuture = absl::InfiniteFuture();
235   constexpr absl::Time ipast = absl::InfinitePast();
236 
237   static_assert(ifuture == ifuture, "");
238   static_assert(ipast == ipast, "");
239   static_assert(ipast < ifuture, "");
240   static_assert(ifuture > ipast, "");
241 
242 #ifdef __cpp_impl_three_way_comparison
243 
244   static_assert((ifuture <=> ifuture) == std::strong_ordering::equal, "");
245   static_assert((ipast <=> ipast) == std::strong_ordering::equal, "");
246   static_assert((ipast <=> ifuture) == std::strong_ordering::less, "");
247   static_assert((ifuture <=> ipast) == std::strong_ordering::greater, "");
248 
249 #endif  // __cpp_impl_three_way_comparison
250 
251   // Arithmetic saturates
252   EXPECT_EQ(ifuture, ifuture + absl::Seconds(1));
253   EXPECT_EQ(ifuture, ifuture - absl::Seconds(1));
254   EXPECT_EQ(ipast, ipast + absl::Seconds(1));
255   EXPECT_EQ(ipast, ipast - absl::Seconds(1));
256 
257   EXPECT_EQ(absl::InfiniteDuration(), ifuture - ifuture);
258   EXPECT_EQ(absl::InfiniteDuration(), ifuture - ipast);
259   EXPECT_EQ(-absl::InfiniteDuration(), ipast - ifuture);
260   EXPECT_EQ(-absl::InfiniteDuration(), ipast - ipast);
261 
262   constexpr absl::Time t = absl::UnixEpoch();  // Any finite time.
263   static_assert(t < ifuture, "");
264   static_assert(t > ipast, "");
265 
266 #ifdef __cpp_impl_three_way_comparison
267 
268   static_assert((t <=> ifuture) == std::strong_ordering::less, "");
269   static_assert((t <=> ipast) == std::strong_ordering::greater, "");
270   static_assert((ipast <=> t) == std::strong_ordering::less, "");
271   static_assert((ifuture <=> t) == std::strong_ordering::greater, "");
272 
273 #endif  // __cpp_impl_three_way_comparison
274 
275   EXPECT_EQ(ifuture, t + absl::InfiniteDuration());
276   EXPECT_EQ(ipast, t - absl::InfiniteDuration());
277 }
278 
TEST(Time,FloorConversion)279 TEST(Time, FloorConversion) {
280 #define TEST_FLOOR_CONVERSION(TO, FROM) \
281   EXPECT_EQ(1, TO(FROM(1001)));         \
282   EXPECT_EQ(1, TO(FROM(1000)));         \
283   EXPECT_EQ(0, TO(FROM(999)));          \
284   EXPECT_EQ(0, TO(FROM(1)));            \
285   EXPECT_EQ(0, TO(FROM(0)));            \
286   EXPECT_EQ(-1, TO(FROM(-1)));          \
287   EXPECT_EQ(-1, TO(FROM(-999)));        \
288   EXPECT_EQ(-1, TO(FROM(-1000)));       \
289   EXPECT_EQ(-2, TO(FROM(-1001)));
290 
291   TEST_FLOOR_CONVERSION(absl::ToUnixMicros, absl::FromUnixNanos);
292   TEST_FLOOR_CONVERSION(absl::ToUnixMillis, absl::FromUnixMicros);
293   TEST_FLOOR_CONVERSION(absl::ToUnixSeconds, absl::FromUnixMillis);
294   TEST_FLOOR_CONVERSION(absl::ToTimeT, absl::FromUnixMillis);
295 
296 #undef TEST_FLOOR_CONVERSION
297 
298   // Tests ToUnixNanos.
299   EXPECT_EQ(1, absl::ToUnixNanos(absl::UnixEpoch() + absl::Nanoseconds(3) / 2));
300   EXPECT_EQ(1, absl::ToUnixNanos(absl::UnixEpoch() + absl::Nanoseconds(1)));
301   EXPECT_EQ(0, absl::ToUnixNanos(absl::UnixEpoch() + absl::Nanoseconds(1) / 2));
302   EXPECT_EQ(0, absl::ToUnixNanos(absl::UnixEpoch() + absl::ZeroDuration()));
303   EXPECT_EQ(-1,
304             absl::ToUnixNanos(absl::UnixEpoch() - absl::Nanoseconds(1) / 2));
305   EXPECT_EQ(-1, absl::ToUnixNanos(absl::UnixEpoch() - absl::Nanoseconds(1)));
306   EXPECT_EQ(-2,
307             absl::ToUnixNanos(absl::UnixEpoch() - absl::Nanoseconds(3) / 2));
308 
309   // Tests ToUniversal, which uses a different epoch than the tests above.
310   EXPECT_EQ(1,
311             absl::ToUniversal(absl::UniversalEpoch() + absl::Nanoseconds(101)));
312   EXPECT_EQ(1,
313             absl::ToUniversal(absl::UniversalEpoch() + absl::Nanoseconds(100)));
314   EXPECT_EQ(0,
315             absl::ToUniversal(absl::UniversalEpoch() + absl::Nanoseconds(99)));
316   EXPECT_EQ(0,
317             absl::ToUniversal(absl::UniversalEpoch() + absl::Nanoseconds(1)));
318   EXPECT_EQ(0,
319             absl::ToUniversal(absl::UniversalEpoch() + absl::ZeroDuration()));
320   EXPECT_EQ(-1,
321             absl::ToUniversal(absl::UniversalEpoch() + absl::Nanoseconds(-1)));
322   EXPECT_EQ(-1,
323             absl::ToUniversal(absl::UniversalEpoch() + absl::Nanoseconds(-99)));
324   EXPECT_EQ(
325       -1, absl::ToUniversal(absl::UniversalEpoch() + absl::Nanoseconds(-100)));
326   EXPECT_EQ(
327       -2, absl::ToUniversal(absl::UniversalEpoch() + absl::Nanoseconds(-101)));
328 
329   // Tests ToTimespec()/TimeFromTimespec()
330   const struct {
331     absl::Time t;
332     timespec ts;
333   } to_ts[] = {
334       {absl::FromUnixSeconds(1) + absl::Nanoseconds(1), {1, 1}},
335       {absl::FromUnixSeconds(1) + absl::Nanoseconds(1) / 2, {1, 0}},
336       {absl::FromUnixSeconds(1) + absl::ZeroDuration(), {1, 0}},
337       {absl::FromUnixSeconds(0) + absl::ZeroDuration(), {0, 0}},
338       {absl::FromUnixSeconds(0) - absl::Nanoseconds(1) / 2, {-1, 999999999}},
339       {absl::FromUnixSeconds(0) - absl::Nanoseconds(1), {-1, 999999999}},
340       {absl::FromUnixSeconds(-1) + absl::Nanoseconds(1), {-1, 1}},
341       {absl::FromUnixSeconds(-1) + absl::Nanoseconds(1) / 2, {-1, 0}},
342       {absl::FromUnixSeconds(-1) + absl::ZeroDuration(), {-1, 0}},
343       {absl::FromUnixSeconds(-1) - absl::Nanoseconds(1) / 2, {-2, 999999999}},
344   };
345   for (const auto& test : to_ts) {
346     EXPECT_THAT(absl::ToTimespec(test.t), TimespecMatcher(test.ts));
347   }
348   const struct {
349     timespec ts;
350     absl::Time t;
351   } from_ts[] = {
352       {{1, 1}, absl::FromUnixSeconds(1) + absl::Nanoseconds(1)},
353       {{1, 0}, absl::FromUnixSeconds(1) + absl::ZeroDuration()},
354       {{0, 0}, absl::FromUnixSeconds(0) + absl::ZeroDuration()},
355       {{0, -1}, absl::FromUnixSeconds(0) - absl::Nanoseconds(1)},
356       {{-1, 999999999}, absl::FromUnixSeconds(0) - absl::Nanoseconds(1)},
357       {{-1, 1}, absl::FromUnixSeconds(-1) + absl::Nanoseconds(1)},
358       {{-1, 0}, absl::FromUnixSeconds(-1) + absl::ZeroDuration()},
359       {{-1, -1}, absl::FromUnixSeconds(-1) - absl::Nanoseconds(1)},
360       {{-2, 999999999}, absl::FromUnixSeconds(-1) - absl::Nanoseconds(1)},
361   };
362   for (const auto& test : from_ts) {
363     EXPECT_EQ(test.t, absl::TimeFromTimespec(test.ts));
364   }
365 
366   // Tests  absl::ToTimeval()/TimeFromTimeval() (same as timespec above)
367   const struct {
368     absl::Time t;
369     timeval tv;
370   } to_tv[] = {
371       {absl::FromUnixSeconds(1) + absl::Microseconds(1), {1, 1}},
372       {absl::FromUnixSeconds(1) + absl::Microseconds(1) / 2, {1, 0}},
373       {absl::FromUnixSeconds(1) + absl::ZeroDuration(), {1, 0}},
374       {absl::FromUnixSeconds(0) + absl::ZeroDuration(), {0, 0}},
375       {absl::FromUnixSeconds(0) - absl::Microseconds(1) / 2, {-1, 999999}},
376       {absl::FromUnixSeconds(0) - absl::Microseconds(1), {-1, 999999}},
377       {absl::FromUnixSeconds(-1) + absl::Microseconds(1), {-1, 1}},
378       {absl::FromUnixSeconds(-1) + absl::Microseconds(1) / 2, {-1, 0}},
379       {absl::FromUnixSeconds(-1) + absl::ZeroDuration(), {-1, 0}},
380       {absl::FromUnixSeconds(-1) - absl::Microseconds(1) / 2, {-2, 999999}},
381   };
382   for (const auto& test : to_tv) {
383     EXPECT_THAT(absl::ToTimeval(test.t), TimevalMatcher(test.tv));
384   }
385   const struct {
386     timeval tv;
387     absl::Time t;
388   } from_tv[] = {
389       {{1, 1}, absl::FromUnixSeconds(1) + absl::Microseconds(1)},
390       {{1, 0}, absl::FromUnixSeconds(1) + absl::ZeroDuration()},
391       {{0, 0}, absl::FromUnixSeconds(0) + absl::ZeroDuration()},
392       {{0, -1}, absl::FromUnixSeconds(0) - absl::Microseconds(1)},
393       {{-1, 999999}, absl::FromUnixSeconds(0) - absl::Microseconds(1)},
394       {{-1, 1}, absl::FromUnixSeconds(-1) + absl::Microseconds(1)},
395       {{-1, 0}, absl::FromUnixSeconds(-1) + absl::ZeroDuration()},
396       {{-1, -1}, absl::FromUnixSeconds(-1) - absl::Microseconds(1)},
397       {{-2, 999999}, absl::FromUnixSeconds(-1) - absl::Microseconds(1)},
398   };
399   for (const auto& test : from_tv) {
400     EXPECT_EQ(test.t, absl::TimeFromTimeval(test.tv));
401   }
402 
403   // Tests flooring near negative infinity.
404   const int64_t min_plus_1 = std::numeric_limits<int64_t>::min() + 1;
405   EXPECT_EQ(min_plus_1, absl::ToUnixSeconds(absl::FromUnixSeconds(min_plus_1)));
406   EXPECT_EQ(std::numeric_limits<int64_t>::min(),
407             absl::ToUnixSeconds(absl::FromUnixSeconds(min_plus_1) -
408                                 absl::Nanoseconds(1) / 2));
409 
410   // Tests flooring near positive infinity.
411   EXPECT_EQ(std::numeric_limits<int64_t>::max(),
412             absl::ToUnixSeconds(
413                 absl::FromUnixSeconds(std::numeric_limits<int64_t>::max()) +
414                 absl::Nanoseconds(1) / 2));
415   EXPECT_EQ(std::numeric_limits<int64_t>::max(),
416             absl::ToUnixSeconds(
417                 absl::FromUnixSeconds(std::numeric_limits<int64_t>::max())));
418   EXPECT_EQ(std::numeric_limits<int64_t>::max() - 1,
419             absl::ToUnixSeconds(
420                 absl::FromUnixSeconds(std::numeric_limits<int64_t>::max()) -
421                 absl::Nanoseconds(1) / 2));
422 }
423 
TEST(Time,RoundtripConversion)424 TEST(Time, RoundtripConversion) {
425 #define TEST_CONVERSION_ROUND_TRIP(SOURCE, FROM, TO, MATCHER) \
426   EXPECT_THAT(TO(FROM(SOURCE)), MATCHER(SOURCE))
427 
428   // FromUnixNanos() and ToUnixNanos()
429   int64_t now_ns = absl::GetCurrentTimeNanos();
430   TEST_CONVERSION_ROUND_TRIP(-1, absl::FromUnixNanos, absl::ToUnixNanos,
431                              testing::Eq);
432   TEST_CONVERSION_ROUND_TRIP(0, absl::FromUnixNanos, absl::ToUnixNanos,
433                              testing::Eq);
434   TEST_CONVERSION_ROUND_TRIP(1, absl::FromUnixNanos, absl::ToUnixNanos,
435                              testing::Eq);
436   TEST_CONVERSION_ROUND_TRIP(now_ns, absl::FromUnixNanos, absl::ToUnixNanos,
437                              testing::Eq)
438       << now_ns;
439 
440   // FromUnixMicros() and ToUnixMicros()
441   int64_t now_us = absl::GetCurrentTimeNanos() / 1000;
442   TEST_CONVERSION_ROUND_TRIP(-1, absl::FromUnixMicros, absl::ToUnixMicros,
443                              testing::Eq);
444   TEST_CONVERSION_ROUND_TRIP(0, absl::FromUnixMicros, absl::ToUnixMicros,
445                              testing::Eq);
446   TEST_CONVERSION_ROUND_TRIP(1, absl::FromUnixMicros, absl::ToUnixMicros,
447                              testing::Eq);
448   TEST_CONVERSION_ROUND_TRIP(now_us, absl::FromUnixMicros, absl::ToUnixMicros,
449                              testing::Eq)
450       << now_us;
451 
452   // FromUnixMillis() and ToUnixMillis()
453   int64_t now_ms = absl::GetCurrentTimeNanos() / 1000000;
454   TEST_CONVERSION_ROUND_TRIP(-1, absl::FromUnixMillis, absl::ToUnixMillis,
455                              testing::Eq);
456   TEST_CONVERSION_ROUND_TRIP(0, absl::FromUnixMillis, absl::ToUnixMillis,
457                              testing::Eq);
458   TEST_CONVERSION_ROUND_TRIP(1, absl::FromUnixMillis, absl::ToUnixMillis,
459                              testing::Eq);
460   TEST_CONVERSION_ROUND_TRIP(now_ms, absl::FromUnixMillis, absl::ToUnixMillis,
461                              testing::Eq)
462       << now_ms;
463 
464   // FromUnixSeconds() and ToUnixSeconds()
465   int64_t now_s = std::time(nullptr);
466   TEST_CONVERSION_ROUND_TRIP(-1, absl::FromUnixSeconds, absl::ToUnixSeconds,
467                              testing::Eq);
468   TEST_CONVERSION_ROUND_TRIP(0, absl::FromUnixSeconds, absl::ToUnixSeconds,
469                              testing::Eq);
470   TEST_CONVERSION_ROUND_TRIP(1, absl::FromUnixSeconds, absl::ToUnixSeconds,
471                              testing::Eq);
472   TEST_CONVERSION_ROUND_TRIP(now_s, absl::FromUnixSeconds, absl::ToUnixSeconds,
473                              testing::Eq)
474       << now_s;
475 
476   // FromTimeT() and ToTimeT()
477   time_t now_time_t = std::time(nullptr);
478   TEST_CONVERSION_ROUND_TRIP(-1, absl::FromTimeT, absl::ToTimeT, testing::Eq);
479   TEST_CONVERSION_ROUND_TRIP(0, absl::FromTimeT, absl::ToTimeT, testing::Eq);
480   TEST_CONVERSION_ROUND_TRIP(1, absl::FromTimeT, absl::ToTimeT, testing::Eq);
481   TEST_CONVERSION_ROUND_TRIP(now_time_t, absl::FromTimeT, absl::ToTimeT,
482                              testing::Eq)
483       << now_time_t;
484 
485   // TimeFromTimeval() and  absl::ToTimeval()
486   timeval tv;
487   tv.tv_sec = -1;
488   tv.tv_usec = 0;
489   TEST_CONVERSION_ROUND_TRIP(tv, absl::TimeFromTimeval, absl::ToTimeval,
490                              TimevalMatcher);
491   tv.tv_sec = -1;
492   tv.tv_usec = 999999;
493   TEST_CONVERSION_ROUND_TRIP(tv, absl::TimeFromTimeval, absl::ToTimeval,
494                              TimevalMatcher);
495   tv.tv_sec = 0;
496   tv.tv_usec = 0;
497   TEST_CONVERSION_ROUND_TRIP(tv, absl::TimeFromTimeval, absl::ToTimeval,
498                              TimevalMatcher);
499   tv.tv_sec = 0;
500   tv.tv_usec = 1;
501   TEST_CONVERSION_ROUND_TRIP(tv, absl::TimeFromTimeval, absl::ToTimeval,
502                              TimevalMatcher);
503   tv.tv_sec = 1;
504   tv.tv_usec = 0;
505   TEST_CONVERSION_ROUND_TRIP(tv, absl::TimeFromTimeval, absl::ToTimeval,
506                              TimevalMatcher);
507 
508   // TimeFromTimespec() and ToTimespec()
509   timespec ts;
510   ts.tv_sec = -1;
511   ts.tv_nsec = 0;
512   TEST_CONVERSION_ROUND_TRIP(ts, absl::TimeFromTimespec, absl::ToTimespec,
513                              TimespecMatcher);
514   ts.tv_sec = -1;
515   ts.tv_nsec = 999999999;
516   TEST_CONVERSION_ROUND_TRIP(ts, absl::TimeFromTimespec, absl::ToTimespec,
517                              TimespecMatcher);
518   ts.tv_sec = 0;
519   ts.tv_nsec = 0;
520   TEST_CONVERSION_ROUND_TRIP(ts, absl::TimeFromTimespec, absl::ToTimespec,
521                              TimespecMatcher);
522   ts.tv_sec = 0;
523   ts.tv_nsec = 1;
524   TEST_CONVERSION_ROUND_TRIP(ts, absl::TimeFromTimespec, absl::ToTimespec,
525                              TimespecMatcher);
526   ts.tv_sec = 1;
527   ts.tv_nsec = 0;
528   TEST_CONVERSION_ROUND_TRIP(ts, absl::TimeFromTimespec, absl::ToTimespec,
529                              TimespecMatcher);
530 
531   // FromUDate() and ToUDate()
532   double now_ud = absl::GetCurrentTimeNanos() / 1000000;
533   TEST_CONVERSION_ROUND_TRIP(-1.5, absl::FromUDate, absl::ToUDate,
534                              testing::DoubleEq);
535   TEST_CONVERSION_ROUND_TRIP(-1, absl::FromUDate, absl::ToUDate,
536                              testing::DoubleEq);
537   TEST_CONVERSION_ROUND_TRIP(-0.5, absl::FromUDate, absl::ToUDate,
538                              testing::DoubleEq);
539   TEST_CONVERSION_ROUND_TRIP(0, absl::FromUDate, absl::ToUDate,
540                              testing::DoubleEq);
541   TEST_CONVERSION_ROUND_TRIP(0.5, absl::FromUDate, absl::ToUDate,
542                              testing::DoubleEq);
543   TEST_CONVERSION_ROUND_TRIP(1, absl::FromUDate, absl::ToUDate,
544                              testing::DoubleEq);
545   TEST_CONVERSION_ROUND_TRIP(1.5, absl::FromUDate, absl::ToUDate,
546                              testing::DoubleEq);
547   TEST_CONVERSION_ROUND_TRIP(now_ud, absl::FromUDate, absl::ToUDate,
548                              testing::DoubleEq)
549       << std::fixed << std::setprecision(17) << now_ud;
550 
551   // FromUniversal() and ToUniversal()
552   int64_t now_uni = ((719162LL * (24 * 60 * 60)) * (1000 * 1000 * 10)) +
553                     (absl::GetCurrentTimeNanos() / 100);
554   TEST_CONVERSION_ROUND_TRIP(-1, absl::FromUniversal, absl::ToUniversal,
555                              testing::Eq);
556   TEST_CONVERSION_ROUND_TRIP(0, absl::FromUniversal, absl::ToUniversal,
557                              testing::Eq);
558   TEST_CONVERSION_ROUND_TRIP(1, absl::FromUniversal, absl::ToUniversal,
559                              testing::Eq);
560   TEST_CONVERSION_ROUND_TRIP(now_uni, absl::FromUniversal, absl::ToUniversal,
561                              testing::Eq)
562       << now_uni;
563 
564 #undef TEST_CONVERSION_ROUND_TRIP
565 }
566 
567 template <typename Duration>
MakeChronoUnixTime(const Duration & d)568 std::chrono::system_clock::time_point MakeChronoUnixTime(const Duration& d) {
569   return std::chrono::system_clock::from_time_t(0) + d;
570 }
571 
TEST(Time,FromChrono)572 TEST(Time, FromChrono) {
573   EXPECT_EQ(absl::FromTimeT(-1),
574             absl::FromChrono(std::chrono::system_clock::from_time_t(-1)));
575   EXPECT_EQ(absl::FromTimeT(0),
576             absl::FromChrono(std::chrono::system_clock::from_time_t(0)));
577   EXPECT_EQ(absl::FromTimeT(1),
578             absl::FromChrono(std::chrono::system_clock::from_time_t(1)));
579 
580   EXPECT_EQ(
581       absl::FromUnixMillis(-1),
582       absl::FromChrono(MakeChronoUnixTime(std::chrono::milliseconds(-1))));
583   EXPECT_EQ(absl::FromUnixMillis(0),
584             absl::FromChrono(MakeChronoUnixTime(std::chrono::milliseconds(0))));
585   EXPECT_EQ(absl::FromUnixMillis(1),
586             absl::FromChrono(MakeChronoUnixTime(std::chrono::milliseconds(1))));
587 
588   // Chrono doesn't define exactly its range and precision (neither does
589   // absl::Time), so let's simply test +/- ~100 years to make sure things work.
590   const auto century_sec = 60 * 60 * 24 * 365 * int64_t{100};
591   const auto century = std::chrono::seconds(century_sec);
592   const auto chrono_future = MakeChronoUnixTime(century);
593   const auto chrono_past = MakeChronoUnixTime(-century);
594   EXPECT_EQ(absl::FromUnixSeconds(century_sec),
595             absl::FromChrono(chrono_future));
596   EXPECT_EQ(absl::FromUnixSeconds(-century_sec), absl::FromChrono(chrono_past));
597 
598   // Roundtrip them both back to chrono.
599   EXPECT_EQ(chrono_future,
600             absl::ToChronoTime(absl::FromUnixSeconds(century_sec)));
601   EXPECT_EQ(chrono_past,
602             absl::ToChronoTime(absl::FromUnixSeconds(-century_sec)));
603 }
604 
TEST(Time,ToChronoTime)605 TEST(Time, ToChronoTime) {
606   EXPECT_EQ(std::chrono::system_clock::from_time_t(-1),
607             absl::ToChronoTime(absl::FromTimeT(-1)));
608   EXPECT_EQ(std::chrono::system_clock::from_time_t(0),
609             absl::ToChronoTime(absl::FromTimeT(0)));
610   EXPECT_EQ(std::chrono::system_clock::from_time_t(1),
611             absl::ToChronoTime(absl::FromTimeT(1)));
612 
613   EXPECT_EQ(MakeChronoUnixTime(std::chrono::milliseconds(-1)),
614             absl::ToChronoTime(absl::FromUnixMillis(-1)));
615   EXPECT_EQ(MakeChronoUnixTime(std::chrono::milliseconds(0)),
616             absl::ToChronoTime(absl::FromUnixMillis(0)));
617   EXPECT_EQ(MakeChronoUnixTime(std::chrono::milliseconds(1)),
618             absl::ToChronoTime(absl::FromUnixMillis(1)));
619 
620   // Time before the Unix epoch should floor, not trunc.
621   const auto tick = absl::Nanoseconds(1) / 4;
622   EXPECT_EQ(std::chrono::system_clock::from_time_t(0) -
623                 std::chrono::system_clock::duration(1),
624             absl::ToChronoTime(absl::UnixEpoch() - tick));
625 }
626 
627 // Check that absl::int128 works as a std::chrono::duration representation.
TEST(Time,Chrono128)628 TEST(Time, Chrono128) {
629   // Define a std::chrono::time_point type whose time[sic]_since_epoch() is
630   // a signed 128-bit count of attoseconds. This has a range and resolution
631   // (currently) beyond those of absl::Time, and undoubtedly also beyond those
632   // of std::chrono::system_clock::time_point.
633   //
634   // Note: The to/from-chrono support should probably be updated to handle
635   // such wide representations.
636   using Timestamp =
637       std::chrono::time_point<std::chrono::system_clock,
638                               std::chrono::duration<absl::int128, std::atto>>;
639 
640   // Expect that we can round-trip the std::chrono::system_clock::time_point
641   // extremes through both absl::Time and Timestamp, and that Timestamp can
642   // handle the (current) absl::Time extremes.
643   //
644   // Note: We should use std::chrono::floor() instead of time_point_cast(),
645   // but floor() is only available since c++17.
646   for (const auto tp : {std::chrono::system_clock::time_point::min(),
647                         std::chrono::system_clock::time_point::max()}) {
648     EXPECT_EQ(tp, absl::ToChronoTime(absl::FromChrono(tp)));
649     EXPECT_EQ(tp, std::chrono::time_point_cast<
650                       std::chrono::system_clock::time_point::duration>(
651                       std::chrono::time_point_cast<Timestamp::duration>(tp)));
652   }
653   Timestamp::duration::rep v = std::numeric_limits<int64_t>::min();
654   v *= Timestamp::duration::period::den;
655   auto ts = Timestamp(Timestamp::duration(v));
656   ts += std::chrono::duration<int64_t, std::atto>(0);
657   EXPECT_EQ(std::numeric_limits<int64_t>::min(),
658             ts.time_since_epoch().count() / Timestamp::duration::period::den);
659   EXPECT_EQ(0,
660             ts.time_since_epoch().count() % Timestamp::duration::period::den);
661   v = std::numeric_limits<int64_t>::max();
662   v *= Timestamp::duration::period::den;
663   ts = Timestamp(Timestamp::duration(v));
664   ts += std::chrono::duration<int64_t, std::atto>(999999999750000000);
665   EXPECT_EQ(std::numeric_limits<int64_t>::max(),
666             ts.time_since_epoch().count() / Timestamp::duration::period::den);
667   EXPECT_EQ(999999999750000000,
668             ts.time_since_epoch().count() % Timestamp::duration::period::den);
669 }
670 
TEST(Time,TimeZoneAt)671 TEST(Time, TimeZoneAt) {
672   const absl::TimeZone nyc =
673       absl::time_internal::LoadTimeZone("America/New_York");
674   const std::string fmt = "%a, %e %b %Y %H:%M:%S %z (%Z)";
675 
676   // A non-transition where the civil time is unique.
677   absl::CivilSecond nov01(2013, 11, 1, 8, 30, 0);
678   const auto nov01_ci = nyc.At(nov01);
679   EXPECT_EQ(absl::TimeZone::TimeInfo::UNIQUE, nov01_ci.kind);
680   EXPECT_EQ("Fri,  1 Nov 2013 08:30:00 -0400 (EDT)",
681             absl::FormatTime(fmt, nov01_ci.pre, nyc));
682   EXPECT_EQ(nov01_ci.pre, nov01_ci.trans);
683   EXPECT_EQ(nov01_ci.pre, nov01_ci.post);
684   EXPECT_EQ(nov01_ci.pre, absl::FromCivil(nov01, nyc));
685 
686   // A Spring DST transition, when there is a gap in civil time
687   // and we prefer the later of the possible interpretations of a
688   // non-existent time.
689   absl::CivilSecond mar13(2011, 3, 13, 2, 15, 0);
690   const auto mar_ci = nyc.At(mar13);
691   EXPECT_EQ(absl::TimeZone::TimeInfo::SKIPPED, mar_ci.kind);
692   EXPECT_EQ("Sun, 13 Mar 2011 03:15:00 -0400 (EDT)",
693             absl::FormatTime(fmt, mar_ci.pre, nyc));
694   EXPECT_EQ("Sun, 13 Mar 2011 03:00:00 -0400 (EDT)",
695             absl::FormatTime(fmt, mar_ci.trans, nyc));
696   EXPECT_EQ("Sun, 13 Mar 2011 01:15:00 -0500 (EST)",
697             absl::FormatTime(fmt, mar_ci.post, nyc));
698   EXPECT_EQ(mar_ci.trans, absl::FromCivil(mar13, nyc));
699 
700   // A Fall DST transition, when civil times are repeated and
701   // we prefer the earlier of the possible interpretations of an
702   // ambiguous time.
703   absl::CivilSecond nov06(2011, 11, 6, 1, 15, 0);
704   const auto nov06_ci = nyc.At(nov06);
705   EXPECT_EQ(absl::TimeZone::TimeInfo::REPEATED, nov06_ci.kind);
706   EXPECT_EQ("Sun,  6 Nov 2011 01:15:00 -0400 (EDT)",
707             absl::FormatTime(fmt, nov06_ci.pre, nyc));
708   EXPECT_EQ("Sun,  6 Nov 2011 01:00:00 -0500 (EST)",
709             absl::FormatTime(fmt, nov06_ci.trans, nyc));
710   EXPECT_EQ("Sun,  6 Nov 2011 01:15:00 -0500 (EST)",
711             absl::FormatTime(fmt, nov06_ci.post, nyc));
712   EXPECT_EQ(nov06_ci.pre, absl::FromCivil(nov06, nyc));
713 
714   // Check that (time_t) -1 is handled correctly.
715   absl::CivilSecond minus1(1969, 12, 31, 18, 59, 59);
716   const auto minus1_cl = nyc.At(minus1);
717   EXPECT_EQ(absl::TimeZone::TimeInfo::UNIQUE, minus1_cl.kind);
718   EXPECT_EQ(-1, absl::ToTimeT(minus1_cl.pre));
719   EXPECT_EQ("Wed, 31 Dec 1969 18:59:59 -0500 (EST)",
720             absl::FormatTime(fmt, minus1_cl.pre, nyc));
721   EXPECT_EQ("Wed, 31 Dec 1969 23:59:59 +0000 (UTC)",
722             absl::FormatTime(fmt, minus1_cl.pre, absl::UTCTimeZone()));
723 }
724 
725 // FromCivil(CivilSecond(year, mon, day, hour, min, sec), UTCTimeZone())
726 // has a specialized fastpath implementation, which we exercise here.
TEST(Time,FromCivilUTC)727 TEST(Time, FromCivilUTC) {
728   const absl::TimeZone utc = absl::UTCTimeZone();
729   const std::string fmt = "%a, %e %b %Y %H:%M:%S %z (%Z)";
730   const int kMax = std::numeric_limits<int>::max();
731   const int kMin = std::numeric_limits<int>::min();
732   absl::Time t;
733 
734   // 292091940881 is the last positive year to use the fastpath.
735   t = absl::FromCivil(
736       absl::CivilSecond(292091940881, kMax, kMax, kMax, kMax, kMax), utc);
737   EXPECT_EQ("Fri, 25 Nov 292277026596 12:21:07 +0000 (UTC)",
738             absl::FormatTime(fmt, t, utc));
739   t = absl::FromCivil(
740       absl::CivilSecond(292091940882, kMax, kMax, kMax, kMax, kMax), utc);
741   EXPECT_EQ("infinite-future", absl::FormatTime(fmt, t, utc));  // no overflow
742 
743   // -292091936940 is the last negative year to use the fastpath.
744   t = absl::FromCivil(
745       absl::CivilSecond(-292091936940, kMin, kMin, kMin, kMin, kMin), utc);
746   EXPECT_EQ("Fri,  1 Nov -292277022657 10:37:52 +0000 (UTC)",
747             absl::FormatTime(fmt, t, utc));
748   t = absl::FromCivil(
749       absl::CivilSecond(-292091936941, kMin, kMin, kMin, kMin, kMin), utc);
750   EXPECT_EQ("infinite-past", absl::FormatTime(fmt, t, utc));  // no underflow
751 
752   // Check that we're counting leap years correctly.
753   t = absl::FromCivil(absl::CivilSecond(1900, 2, 28, 23, 59, 59), utc);
754   EXPECT_EQ("Wed, 28 Feb 1900 23:59:59 +0000 (UTC)",
755             absl::FormatTime(fmt, t, utc));
756   t = absl::FromCivil(absl::CivilSecond(1900, 3, 1, 0, 0, 0), utc);
757   EXPECT_EQ("Thu,  1 Mar 1900 00:00:00 +0000 (UTC)",
758             absl::FormatTime(fmt, t, utc));
759   t = absl::FromCivil(absl::CivilSecond(2000, 2, 29, 23, 59, 59), utc);
760   EXPECT_EQ("Tue, 29 Feb 2000 23:59:59 +0000 (UTC)",
761             absl::FormatTime(fmt, t, utc));
762   t = absl::FromCivil(absl::CivilSecond(2000, 3, 1, 0, 0, 0), utc);
763   EXPECT_EQ("Wed,  1 Mar 2000 00:00:00 +0000 (UTC)",
764             absl::FormatTime(fmt, t, utc));
765 }
766 
TEST(Time,ToTM)767 TEST(Time, ToTM) {
768   const absl::TimeZone utc = absl::UTCTimeZone();
769 
770   // Compares the results of absl::ToTM() to gmtime_r() for lots of times over
771   // the course of a few days.
772   const absl::Time start =
773       absl::FromCivil(absl::CivilSecond(2014, 1, 2, 3, 4, 5), utc);
774   const absl::Time end =
775       absl::FromCivil(absl::CivilSecond(2014, 1, 5, 3, 4, 5), utc);
776   for (absl::Time t = start; t < end; t += absl::Seconds(30)) {
777     const struct tm tm_bt = absl::ToTM(t, utc);
778     const time_t tt = absl::ToTimeT(t);
779     struct tm tm_lc;
780 #ifdef _WIN32
781     gmtime_s(&tm_lc, &tt);
782 #else
783     gmtime_r(&tt, &tm_lc);
784 #endif
785     EXPECT_EQ(tm_lc.tm_year, tm_bt.tm_year);
786     EXPECT_EQ(tm_lc.tm_mon, tm_bt.tm_mon);
787     EXPECT_EQ(tm_lc.tm_mday, tm_bt.tm_mday);
788     EXPECT_EQ(tm_lc.tm_hour, tm_bt.tm_hour);
789     EXPECT_EQ(tm_lc.tm_min, tm_bt.tm_min);
790     EXPECT_EQ(tm_lc.tm_sec, tm_bt.tm_sec);
791     EXPECT_EQ(tm_lc.tm_wday, tm_bt.tm_wday);
792     EXPECT_EQ(tm_lc.tm_yday, tm_bt.tm_yday);
793     EXPECT_EQ(tm_lc.tm_isdst, tm_bt.tm_isdst);
794 
795     ASSERT_FALSE(HasFailure());
796   }
797 
798   // Checks that the tm_isdst field is correct when in standard time.
799   const absl::TimeZone nyc =
800       absl::time_internal::LoadTimeZone("America/New_York");
801   absl::Time t = absl::FromCivil(absl::CivilSecond(2014, 3, 1, 0, 0, 0), nyc);
802   struct tm tm = absl::ToTM(t, nyc);
803   EXPECT_FALSE(tm.tm_isdst);
804 
805   // Checks that the tm_isdst field is correct when in daylight time.
806   t = absl::FromCivil(absl::CivilSecond(2014, 4, 1, 0, 0, 0), nyc);
807   tm = absl::ToTM(t, nyc);
808   EXPECT_TRUE(tm.tm_isdst);
809 
810   // Checks overflow.
811   tm = absl::ToTM(absl::InfiniteFuture(), nyc);
812   EXPECT_EQ(std::numeric_limits<int>::max() - 1900, tm.tm_year);
813   EXPECT_EQ(11, tm.tm_mon);
814   EXPECT_EQ(31, tm.tm_mday);
815   EXPECT_EQ(23, tm.tm_hour);
816   EXPECT_EQ(59, tm.tm_min);
817   EXPECT_EQ(59, tm.tm_sec);
818   EXPECT_EQ(4, tm.tm_wday);
819   EXPECT_EQ(364, tm.tm_yday);
820   EXPECT_FALSE(tm.tm_isdst);
821 
822   // Checks underflow.
823   tm = absl::ToTM(absl::InfinitePast(), nyc);
824   EXPECT_EQ(std::numeric_limits<int>::min(), tm.tm_year);
825   EXPECT_EQ(0, tm.tm_mon);
826   EXPECT_EQ(1, tm.tm_mday);
827   EXPECT_EQ(0, tm.tm_hour);
828   EXPECT_EQ(0, tm.tm_min);
829   EXPECT_EQ(0, tm.tm_sec);
830   EXPECT_EQ(0, tm.tm_wday);
831   EXPECT_EQ(0, tm.tm_yday);
832   EXPECT_FALSE(tm.tm_isdst);
833 }
834 
TEST(Time,FromTM)835 TEST(Time, FromTM) {
836   const absl::TimeZone nyc =
837       absl::time_internal::LoadTimeZone("America/New_York");
838 
839   // Verifies that tm_isdst doesn't affect anything when the time is unique.
840   struct tm tm;
841   std::memset(&tm, 0, sizeof(tm));
842   tm.tm_year = 2014 - 1900;
843   tm.tm_mon = 6 - 1;
844   tm.tm_mday = 28;
845   tm.tm_hour = 1;
846   tm.tm_min = 2;
847   tm.tm_sec = 3;
848   tm.tm_isdst = -1;
849   absl::Time t = absl::FromTM(tm, nyc);
850   EXPECT_EQ("2014-06-28T01:02:03-04:00", absl::FormatTime(t, nyc));  // DST
851   tm.tm_isdst = 0;
852   t = absl::FromTM(tm, nyc);
853   EXPECT_EQ("2014-06-28T01:02:03-04:00", absl::FormatTime(t, nyc));  // DST
854   tm.tm_isdst = 1;
855   t = absl::FromTM(tm, nyc);
856   EXPECT_EQ("2014-06-28T01:02:03-04:00", absl::FormatTime(t, nyc));  // DST
857 
858   // Adjusts tm to refer to an ambiguous time.
859   tm.tm_year = 2014 - 1900;
860   tm.tm_mon = 11 - 1;
861   tm.tm_mday = 2;
862   tm.tm_hour = 1;
863   tm.tm_min = 30;
864   tm.tm_sec = 42;
865   tm.tm_isdst = -1;
866   t = absl::FromTM(tm, nyc);
867   EXPECT_EQ("2014-11-02T01:30:42-04:00", absl::FormatTime(t, nyc));  // DST
868   tm.tm_isdst = 0;
869   t = absl::FromTM(tm, nyc);
870   EXPECT_EQ("2014-11-02T01:30:42-05:00", absl::FormatTime(t, nyc));  // STD
871   tm.tm_isdst = 1;
872   t = absl::FromTM(tm, nyc);
873   EXPECT_EQ("2014-11-02T01:30:42-04:00", absl::FormatTime(t, nyc));  // DST
874 
875   // Adjusts tm to refer to a skipped time.
876   tm.tm_year = 2014 - 1900;
877   tm.tm_mon = 3 - 1;
878   tm.tm_mday = 9;
879   tm.tm_hour = 2;
880   tm.tm_min = 30;
881   tm.tm_sec = 42;
882   tm.tm_isdst = -1;
883   t = absl::FromTM(tm, nyc);
884   EXPECT_EQ("2014-03-09T03:30:42-04:00", absl::FormatTime(t, nyc));  // DST
885   tm.tm_isdst = 0;
886   t = absl::FromTM(tm, nyc);
887   EXPECT_EQ("2014-03-09T01:30:42-05:00", absl::FormatTime(t, nyc));  // STD
888   tm.tm_isdst = 1;
889   t = absl::FromTM(tm, nyc);
890   EXPECT_EQ("2014-03-09T03:30:42-04:00", absl::FormatTime(t, nyc));  // DST
891 
892   // Adjusts tm to refer to a time with a year larger than 2147483647.
893   tm.tm_year = 2147483647 - 1900 + 1;
894   tm.tm_mon = 6 - 1;
895   tm.tm_mday = 28;
896   tm.tm_hour = 1;
897   tm.tm_min = 2;
898   tm.tm_sec = 3;
899   tm.tm_isdst = -1;
900   t = absl::FromTM(tm, absl::UTCTimeZone());
901   EXPECT_EQ("2147483648-06-28T01:02:03+00:00",
902             absl::FormatTime(t, absl::UTCTimeZone()));
903 
904   // Adjusts tm to refer to a time with a very large month.
905   tm.tm_year = 2019 - 1900;
906   tm.tm_mon = 2147483647;
907   tm.tm_mday = 28;
908   tm.tm_hour = 1;
909   tm.tm_min = 2;
910   tm.tm_sec = 3;
911   tm.tm_isdst = -1;
912   t = absl::FromTM(tm, absl::UTCTimeZone());
913   EXPECT_EQ("178958989-08-28T01:02:03+00:00",
914             absl::FormatTime(t, absl::UTCTimeZone()));
915 }
916 
TEST(Time,TMRoundTrip)917 TEST(Time, TMRoundTrip) {
918   const absl::TimeZone nyc =
919       absl::time_internal::LoadTimeZone("America/New_York");
920 
921   // Test round-tripping across a skipped transition
922   absl::Time start = absl::FromCivil(absl::CivilHour(2014, 3, 9, 0), nyc);
923   absl::Time end = absl::FromCivil(absl::CivilHour(2014, 3, 9, 4), nyc);
924   for (absl::Time t = start; t < end; t += absl::Minutes(1)) {
925     struct tm tm = absl::ToTM(t, nyc);
926     absl::Time rt = absl::FromTM(tm, nyc);
927     EXPECT_EQ(rt, t);
928   }
929 
930   // Test round-tripping across an ambiguous transition
931   start = absl::FromCivil(absl::CivilHour(2014, 11, 2, 0), nyc);
932   end = absl::FromCivil(absl::CivilHour(2014, 11, 2, 4), nyc);
933   for (absl::Time t = start; t < end; t += absl::Minutes(1)) {
934     struct tm tm = absl::ToTM(t, nyc);
935     absl::Time rt = absl::FromTM(tm, nyc);
936     EXPECT_EQ(rt, t);
937   }
938 
939   // Test round-tripping of unique instants crossing a day boundary
940   start = absl::FromCivil(absl::CivilHour(2014, 6, 27, 22), nyc);
941   end = absl::FromCivil(absl::CivilHour(2014, 6, 28, 4), nyc);
942   for (absl::Time t = start; t < end; t += absl::Minutes(1)) {
943     struct tm tm = absl::ToTM(t, nyc);
944     absl::Time rt = absl::FromTM(tm, nyc);
945     EXPECT_EQ(rt, t);
946   }
947 }
948 
TEST(Time,Range)949 TEST(Time, Range) {
950   // The API's documented range is +/- 100 billion years.
951   const absl::Duration range = absl::Hours(24) * 365.2425 * 100000000000;
952 
953   // Arithmetic and comparison still works at +/-range around base values.
954   absl::Time bases[2] = {absl::UnixEpoch(), absl::Now()};
955   for (const auto base : bases) {
956     absl::Time bottom = base - range;
957     EXPECT_GT(bottom, bottom - absl::Nanoseconds(1));
958     EXPECT_LT(bottom, bottom + absl::Nanoseconds(1));
959     absl::Time top = base + range;
960     EXPECT_GT(top, top - absl::Nanoseconds(1));
961     EXPECT_LT(top, top + absl::Nanoseconds(1));
962     absl::Duration full_range = 2 * range;
963     EXPECT_EQ(full_range, top - bottom);
964     EXPECT_EQ(-full_range, bottom - top);
965   }
966 }
967 
TEST(Time,Limits)968 TEST(Time, Limits) {
969   // It is an implementation detail that Time().rep_ == ZeroDuration(),
970   // and that the resolution of a Duration is 1/4 of a nanosecond.
971   const absl::Time zero;
972   const absl::Time max =
973       zero + absl::Seconds(std::numeric_limits<int64_t>::max()) +
974       absl::Nanoseconds(999999999) + absl::Nanoseconds(3) / 4;
975   const absl::Time min =
976       zero + absl::Seconds(std::numeric_limits<int64_t>::min());
977 
978   // Some simple max/min bounds checks.
979   EXPECT_LT(max, absl::InfiniteFuture());
980   EXPECT_GT(min, absl::InfinitePast());
981   EXPECT_LT(zero, max);
982   EXPECT_GT(zero, min);
983   EXPECT_GE(absl::UnixEpoch(), min);
984   EXPECT_LT(absl::UnixEpoch(), max);
985 
986   // Check sign of Time differences.
987   EXPECT_LT(absl::ZeroDuration(), max - zero);
988   EXPECT_LT(absl::ZeroDuration(),
989             zero - absl::Nanoseconds(1) / 4 - min);  // avoid zero - min
990 
991   // Arithmetic works at max - 0.25ns and min + 0.25ns.
992   EXPECT_GT(max, max - absl::Nanoseconds(1) / 4);
993   EXPECT_LT(min, min + absl::Nanoseconds(1) / 4);
994 }
995 
TEST(Time,ConversionSaturation)996 TEST(Time, ConversionSaturation) {
997   const absl::TimeZone utc = absl::UTCTimeZone();
998   absl::Time t;
999 
1000   const auto max_time_t = std::numeric_limits<time_t>::max();
1001   const auto min_time_t = std::numeric_limits<time_t>::min();
1002   time_t tt = max_time_t - 1;
1003   t = absl::FromTimeT(tt);
1004   tt = absl::ToTimeT(t);
1005   EXPECT_EQ(max_time_t - 1, tt);
1006   t += absl::Seconds(1);
1007   tt = absl::ToTimeT(t);
1008   EXPECT_EQ(max_time_t, tt);
1009   t += absl::Seconds(1);  // no effect
1010   tt = absl::ToTimeT(t);
1011   EXPECT_EQ(max_time_t, tt);
1012 
1013   tt = min_time_t + 1;
1014   t = absl::FromTimeT(tt);
1015   tt = absl::ToTimeT(t);
1016   EXPECT_EQ(min_time_t + 1, tt);
1017   t -= absl::Seconds(1);
1018   tt = absl::ToTimeT(t);
1019   EXPECT_EQ(min_time_t, tt);
1020   t -= absl::Seconds(1);  // no effect
1021   tt = absl::ToTimeT(t);
1022   EXPECT_EQ(min_time_t, tt);
1023 
1024   const auto max_timeval_sec =
1025       std::numeric_limits<decltype(timeval::tv_sec)>::max();
1026   const auto min_timeval_sec =
1027       std::numeric_limits<decltype(timeval::tv_sec)>::min();
1028   timeval tv;
1029   tv.tv_sec = max_timeval_sec;
1030   tv.tv_usec = 999998;
1031   t = absl::TimeFromTimeval(tv);
1032   tv = absl::ToTimeval(t);
1033   EXPECT_EQ(max_timeval_sec, tv.tv_sec);
1034   EXPECT_EQ(999998, tv.tv_usec);
1035   t += absl::Microseconds(1);
1036   tv = absl::ToTimeval(t);
1037   EXPECT_EQ(max_timeval_sec, tv.tv_sec);
1038   EXPECT_EQ(999999, tv.tv_usec);
1039   t += absl::Microseconds(1);  // no effect
1040   tv = absl::ToTimeval(t);
1041   EXPECT_EQ(max_timeval_sec, tv.tv_sec);
1042   EXPECT_EQ(999999, tv.tv_usec);
1043 
1044   tv.tv_sec = min_timeval_sec;
1045   tv.tv_usec = 1;
1046   t = absl::TimeFromTimeval(tv);
1047   tv = absl::ToTimeval(t);
1048   EXPECT_EQ(min_timeval_sec, tv.tv_sec);
1049   EXPECT_EQ(1, tv.tv_usec);
1050   t -= absl::Microseconds(1);
1051   tv = absl::ToTimeval(t);
1052   EXPECT_EQ(min_timeval_sec, tv.tv_sec);
1053   EXPECT_EQ(0, tv.tv_usec);
1054   t -= absl::Microseconds(1);  // no effect
1055   tv = absl::ToTimeval(t);
1056   EXPECT_EQ(min_timeval_sec, tv.tv_sec);
1057   EXPECT_EQ(0, tv.tv_usec);
1058 
1059   const auto max_timespec_sec =
1060       std::numeric_limits<decltype(timespec::tv_sec)>::max();
1061   const auto min_timespec_sec =
1062       std::numeric_limits<decltype(timespec::tv_sec)>::min();
1063   timespec ts;
1064   ts.tv_sec = max_timespec_sec;
1065   ts.tv_nsec = 999999998;
1066   t = absl::TimeFromTimespec(ts);
1067   ts = absl::ToTimespec(t);
1068   EXPECT_EQ(max_timespec_sec, ts.tv_sec);
1069   EXPECT_EQ(999999998, ts.tv_nsec);
1070   t += absl::Nanoseconds(1);
1071   ts = absl::ToTimespec(t);
1072   EXPECT_EQ(max_timespec_sec, ts.tv_sec);
1073   EXPECT_EQ(999999999, ts.tv_nsec);
1074   t += absl::Nanoseconds(1);  // no effect
1075   ts = absl::ToTimespec(t);
1076   EXPECT_EQ(max_timespec_sec, ts.tv_sec);
1077   EXPECT_EQ(999999999, ts.tv_nsec);
1078 
1079   ts.tv_sec = min_timespec_sec;
1080   ts.tv_nsec = 1;
1081   t = absl::TimeFromTimespec(ts);
1082   ts = absl::ToTimespec(t);
1083   EXPECT_EQ(min_timespec_sec, ts.tv_sec);
1084   EXPECT_EQ(1, ts.tv_nsec);
1085   t -= absl::Nanoseconds(1);
1086   ts = absl::ToTimespec(t);
1087   EXPECT_EQ(min_timespec_sec, ts.tv_sec);
1088   EXPECT_EQ(0, ts.tv_nsec);
1089   t -= absl::Nanoseconds(1);  // no effect
1090   ts = absl::ToTimespec(t);
1091   EXPECT_EQ(min_timespec_sec, ts.tv_sec);
1092   EXPECT_EQ(0, ts.tv_nsec);
1093 
1094   // Checks how TimeZone::At() saturates on infinities.
1095   auto ci = utc.At(absl::InfiniteFuture());
1096   EXPECT_CIVIL_INFO(ci, std::numeric_limits<int64_t>::max(), 12, 31, 23, 59, 59,
1097                     0, false);
1098   EXPECT_EQ(absl::InfiniteDuration(), ci.subsecond);
1099   EXPECT_EQ(absl::Weekday::thursday, absl::GetWeekday(ci.cs));
1100   EXPECT_EQ(365, absl::GetYearDay(ci.cs));
1101   EXPECT_STREQ("-00", ci.zone_abbr);  // artifact of TimeZone::At()
1102   ci = utc.At(absl::InfinitePast());
1103   EXPECT_CIVIL_INFO(ci, std::numeric_limits<int64_t>::min(), 1, 1, 0, 0, 0, 0,
1104                     false);
1105   EXPECT_EQ(-absl::InfiniteDuration(), ci.subsecond);
1106   EXPECT_EQ(absl::Weekday::sunday, absl::GetWeekday(ci.cs));
1107   EXPECT_EQ(1, absl::GetYearDay(ci.cs));
1108   EXPECT_STREQ("-00", ci.zone_abbr);  // artifact of TimeZone::At()
1109 
1110   // Approach the maximal Time value from below.
1111   t = absl::FromCivil(absl::CivilSecond(292277026596, 12, 4, 15, 30, 6), utc);
1112   EXPECT_EQ("292277026596-12-04T15:30:06+00:00",
1113             absl::FormatTime(absl::RFC3339_full, t, utc));
1114   t = absl::FromCivil(absl::CivilSecond(292277026596, 12, 4, 15, 30, 7), utc);
1115   EXPECT_EQ("292277026596-12-04T15:30:07+00:00",
1116             absl::FormatTime(absl::RFC3339_full, t, utc));
1117   EXPECT_EQ(
1118       absl::UnixEpoch() + absl::Seconds(std::numeric_limits<int64_t>::max()),
1119       t);
1120 
1121   // Checks that we can also get the maximal Time value for a far-east zone.
1122   const absl::TimeZone plus14 = absl::FixedTimeZone(14 * 60 * 60);
1123   t = absl::FromCivil(absl::CivilSecond(292277026596, 12, 5, 5, 30, 7), plus14);
1124   EXPECT_EQ("292277026596-12-05T05:30:07+14:00",
1125             absl::FormatTime(absl::RFC3339_full, t, plus14));
1126   EXPECT_EQ(
1127       absl::UnixEpoch() + absl::Seconds(std::numeric_limits<int64_t>::max()),
1128       t);
1129 
1130   // One second later should push us to infinity.
1131   t = absl::FromCivil(absl::CivilSecond(292277026596, 12, 4, 15, 30, 8), utc);
1132   EXPECT_EQ("infinite-future", absl::FormatTime(absl::RFC3339_full, t, utc));
1133 
1134   // Approach the minimal Time value from above.
1135   t = absl::FromCivil(absl::CivilSecond(-292277022657, 1, 27, 8, 29, 53), utc);
1136   EXPECT_EQ("-292277022657-01-27T08:29:53+00:00",
1137             absl::FormatTime(absl::RFC3339_full, t, utc));
1138   t = absl::FromCivil(absl::CivilSecond(-292277022657, 1, 27, 8, 29, 52), utc);
1139   EXPECT_EQ("-292277022657-01-27T08:29:52+00:00",
1140             absl::FormatTime(absl::RFC3339_full, t, utc));
1141   EXPECT_EQ(
1142       absl::UnixEpoch() + absl::Seconds(std::numeric_limits<int64_t>::min()),
1143       t);
1144 
1145   // Checks that we can also get the minimal Time value for a far-west zone.
1146   const absl::TimeZone minus12 = absl::FixedTimeZone(-12 * 60 * 60);
1147   t = absl::FromCivil(absl::CivilSecond(-292277022657, 1, 26, 20, 29, 52),
1148                       minus12);
1149   EXPECT_EQ("-292277022657-01-26T20:29:52-12:00",
1150             absl::FormatTime(absl::RFC3339_full, t, minus12));
1151   EXPECT_EQ(
1152       absl::UnixEpoch() + absl::Seconds(std::numeric_limits<int64_t>::min()),
1153       t);
1154 
1155   // One second before should push us to -infinity.
1156   t = absl::FromCivil(absl::CivilSecond(-292277022657, 1, 27, 8, 29, 51), utc);
1157   EXPECT_EQ("infinite-past", absl::FormatTime(absl::RFC3339_full, t, utc));
1158 }
1159 
1160 // In zones with POSIX-style recurring rules we use special logic to
1161 // handle conversions in the distant future.  Here we check the limits
1162 // of those conversions, particularly with respect to integer overflow.
TEST(Time,ExtendedConversionSaturation)1163 TEST(Time, ExtendedConversionSaturation) {
1164   const absl::TimeZone syd =
1165       absl::time_internal::LoadTimeZone("Australia/Sydney");
1166   const absl::TimeZone nyc =
1167       absl::time_internal::LoadTimeZone("America/New_York");
1168   const absl::Time max =
1169       absl::FromUnixSeconds(std::numeric_limits<int64_t>::max());
1170   absl::TimeZone::CivilInfo ci;
1171   absl::Time t;
1172 
1173   // The maximal time converted in each zone.
1174   ci = syd.At(max);
1175   EXPECT_CIVIL_INFO(ci, 292277026596, 12, 5, 2, 30, 7, 39600, true);
1176   t = absl::FromCivil(absl::CivilSecond(292277026596, 12, 5, 2, 30, 7), syd);
1177   EXPECT_EQ(max, t);
1178   ci = nyc.At(max);
1179   EXPECT_CIVIL_INFO(ci, 292277026596, 12, 4, 10, 30, 7, -18000, false);
1180   t = absl::FromCivil(absl::CivilSecond(292277026596, 12, 4, 10, 30, 7), nyc);
1181   EXPECT_EQ(max, t);
1182 
1183   // One second later should push us to infinity.
1184   t = absl::FromCivil(absl::CivilSecond(292277026596, 12, 5, 2, 30, 8), syd);
1185   EXPECT_EQ(absl::InfiniteFuture(), t);
1186   t = absl::FromCivil(absl::CivilSecond(292277026596, 12, 4, 10, 30, 8), nyc);
1187   EXPECT_EQ(absl::InfiniteFuture(), t);
1188 
1189   // And we should stick there.
1190   t = absl::FromCivil(absl::CivilSecond(292277026596, 12, 5, 2, 30, 9), syd);
1191   EXPECT_EQ(absl::InfiniteFuture(), t);
1192   t = absl::FromCivil(absl::CivilSecond(292277026596, 12, 4, 10, 30, 9), nyc);
1193   EXPECT_EQ(absl::InfiniteFuture(), t);
1194 
1195   // All the way up to a saturated date/time, without overflow.
1196   t = absl::FromCivil(absl::CivilSecond::max(), syd);
1197   EXPECT_EQ(absl::InfiniteFuture(), t);
1198   t = absl::FromCivil(absl::CivilSecond::max(), nyc);
1199   EXPECT_EQ(absl::InfiniteFuture(), t);
1200 }
1201 
TEST(Time,FromCivilAlignment)1202 TEST(Time, FromCivilAlignment) {
1203   const absl::TimeZone utc = absl::UTCTimeZone();
1204   const absl::CivilSecond cs(2015, 2, 3, 4, 5, 6);
1205   absl::Time t = absl::FromCivil(cs, utc);
1206   EXPECT_EQ("2015-02-03T04:05:06+00:00", absl::FormatTime(t, utc));
1207   t = absl::FromCivil(absl::CivilMinute(cs), utc);
1208   EXPECT_EQ("2015-02-03T04:05:00+00:00", absl::FormatTime(t, utc));
1209   t = absl::FromCivil(absl::CivilHour(cs), utc);
1210   EXPECT_EQ("2015-02-03T04:00:00+00:00", absl::FormatTime(t, utc));
1211   t = absl::FromCivil(absl::CivilDay(cs), utc);
1212   EXPECT_EQ("2015-02-03T00:00:00+00:00", absl::FormatTime(t, utc));
1213   t = absl::FromCivil(absl::CivilMonth(cs), utc);
1214   EXPECT_EQ("2015-02-01T00:00:00+00:00", absl::FormatTime(t, utc));
1215   t = absl::FromCivil(absl::CivilYear(cs), utc);
1216   EXPECT_EQ("2015-01-01T00:00:00+00:00", absl::FormatTime(t, utc));
1217 }
1218 
TEST(Time,LegacyDateTime)1219 TEST(Time, LegacyDateTime) {
1220   const absl::TimeZone utc = absl::UTCTimeZone();
1221   const std::string ymdhms = "%Y-%m-%d %H:%M:%S";
1222   const int kMax = std::numeric_limits<int>::max();
1223   const int kMin = std::numeric_limits<int>::min();
1224   absl::Time t;
1225 
1226   t = absl::FromDateTime(std::numeric_limits<absl::civil_year_t>::max(), kMax,
1227                          kMax, kMax, kMax, kMax, utc);
1228   EXPECT_EQ("infinite-future",
1229             absl::FormatTime(ymdhms, t, utc));  // no overflow
1230   t = absl::FromDateTime(std::numeric_limits<absl::civil_year_t>::min(), kMin,
1231                          kMin, kMin, kMin, kMin, utc);
1232   EXPECT_EQ("infinite-past", absl::FormatTime(ymdhms, t, utc));  // no overflow
1233 
1234   // Check normalization.
1235   EXPECT_TRUE(absl::ConvertDateTime(2013, 10, 32, 8, 30, 0, utc).normalized);
1236   t = absl::FromDateTime(2015, 1, 1, 0, 0, 60, utc);
1237   EXPECT_EQ("2015-01-01 00:01:00", absl::FormatTime(ymdhms, t, utc));
1238   t = absl::FromDateTime(2015, 1, 1, 0, 60, 0, utc);
1239   EXPECT_EQ("2015-01-01 01:00:00", absl::FormatTime(ymdhms, t, utc));
1240   t = absl::FromDateTime(2015, 1, 1, 24, 0, 0, utc);
1241   EXPECT_EQ("2015-01-02 00:00:00", absl::FormatTime(ymdhms, t, utc));
1242   t = absl::FromDateTime(2015, 1, 32, 0, 0, 0, utc);
1243   EXPECT_EQ("2015-02-01 00:00:00", absl::FormatTime(ymdhms, t, utc));
1244   t = absl::FromDateTime(2015, 13, 1, 0, 0, 0, utc);
1245   EXPECT_EQ("2016-01-01 00:00:00", absl::FormatTime(ymdhms, t, utc));
1246   t = absl::FromDateTime(2015, 13, 32, 60, 60, 60, utc);
1247   EXPECT_EQ("2016-02-03 13:01:00", absl::FormatTime(ymdhms, t, utc));
1248   t = absl::FromDateTime(2015, 1, 1, 0, 0, -1, utc);
1249   EXPECT_EQ("2014-12-31 23:59:59", absl::FormatTime(ymdhms, t, utc));
1250   t = absl::FromDateTime(2015, 1, 1, 0, -1, 0, utc);
1251   EXPECT_EQ("2014-12-31 23:59:00", absl::FormatTime(ymdhms, t, utc));
1252   t = absl::FromDateTime(2015, 1, 1, -1, 0, 0, utc);
1253   EXPECT_EQ("2014-12-31 23:00:00", absl::FormatTime(ymdhms, t, utc));
1254   t = absl::FromDateTime(2015, 1, -1, 0, 0, 0, utc);
1255   EXPECT_EQ("2014-12-30 00:00:00", absl::FormatTime(ymdhms, t, utc));
1256   t = absl::FromDateTime(2015, -1, 1, 0, 0, 0, utc);
1257   EXPECT_EQ("2014-11-01 00:00:00", absl::FormatTime(ymdhms, t, utc));
1258   t = absl::FromDateTime(2015, -1, -1, -1, -1, -1, utc);
1259   EXPECT_EQ("2014-10-29 22:58:59", absl::FormatTime(ymdhms, t, utc));
1260 }
1261 
TEST(Time,NextTransitionUTC)1262 TEST(Time, NextTransitionUTC) {
1263   const auto tz = absl::UTCTimeZone();
1264   absl::TimeZone::CivilTransition trans;
1265 
1266   auto t = absl::InfinitePast();
1267   EXPECT_FALSE(tz.NextTransition(t, &trans));
1268 
1269   t = absl::InfiniteFuture();
1270   EXPECT_FALSE(tz.NextTransition(t, &trans));
1271 }
1272 
TEST(Time,PrevTransitionUTC)1273 TEST(Time, PrevTransitionUTC) {
1274   const auto tz = absl::UTCTimeZone();
1275   absl::TimeZone::CivilTransition trans;
1276 
1277   auto t = absl::InfiniteFuture();
1278   EXPECT_FALSE(tz.PrevTransition(t, &trans));
1279 
1280   t = absl::InfinitePast();
1281   EXPECT_FALSE(tz.PrevTransition(t, &trans));
1282 }
1283 
TEST(Time,NextTransitionNYC)1284 TEST(Time, NextTransitionNYC) {
1285   const auto tz = absl::time_internal::LoadTimeZone("America/New_York");
1286   absl::TimeZone::CivilTransition trans;
1287 
1288   auto t = absl::FromCivil(absl::CivilSecond(2018, 6, 30, 0, 0, 0), tz);
1289   EXPECT_TRUE(tz.NextTransition(t, &trans));
1290   EXPECT_EQ(absl::CivilSecond(2018, 11, 4, 2, 0, 0), trans.from);
1291   EXPECT_EQ(absl::CivilSecond(2018, 11, 4, 1, 0, 0), trans.to);
1292 
1293   t = absl::InfiniteFuture();
1294   EXPECT_FALSE(tz.NextTransition(t, &trans));
1295 
1296   t = absl::InfinitePast();
1297   EXPECT_TRUE(tz.NextTransition(t, &trans));
1298   if (trans.from == absl::CivilSecond(1918, 03, 31, 2, 0, 0)) {
1299     // It looks like the tzdata is only 32 bit (probably macOS),
1300     // which bottoms out at 1901-12-13T20:45:52+00:00.
1301     EXPECT_EQ(absl::CivilSecond(1918, 3, 31, 3, 0, 0), trans.to);
1302   } else {
1303     EXPECT_EQ(absl::CivilSecond(1883, 11, 18, 12, 3, 58), trans.from);
1304     EXPECT_EQ(absl::CivilSecond(1883, 11, 18, 12, 0, 0), trans.to);
1305   }
1306 }
1307 
TEST(Time,PrevTransitionNYC)1308 TEST(Time, PrevTransitionNYC) {
1309   const auto tz = absl::time_internal::LoadTimeZone("America/New_York");
1310   absl::TimeZone::CivilTransition trans;
1311 
1312   auto t = absl::FromCivil(absl::CivilSecond(2018, 6, 30, 0, 0, 0), tz);
1313   EXPECT_TRUE(tz.PrevTransition(t, &trans));
1314   EXPECT_EQ(absl::CivilSecond(2018, 3, 11, 2, 0, 0), trans.from);
1315   EXPECT_EQ(absl::CivilSecond(2018, 3, 11, 3, 0, 0), trans.to);
1316 
1317   t = absl::InfinitePast();
1318   EXPECT_FALSE(tz.PrevTransition(t, &trans));
1319 
1320   t = absl::InfiniteFuture();
1321   EXPECT_TRUE(tz.PrevTransition(t, &trans));
1322   // We have a transition but we don't know which one.
1323 }
1324 
TEST(Time,AbslStringify)1325 TEST(Time, AbslStringify) {
1326   // FormatTime is already well tested, so just use one test case here to
1327   // verify that StrFormat("%v", t) works as expected.
1328   absl::Time t = absl::Now();
1329   EXPECT_EQ(absl::StrFormat("%v", t), absl::FormatTime(t));
1330 }
1331 
1332 }  // namespace
1333