ladybird/Tests/LibUnicode/TestTimeZone.cpp
Timothy Flynn 672a555f98 LibCore+LibJS+LibUnicode: Port retrieving time zone offsets to ICU
The changes to tests are due to LibTimeZone incorrectly interpreting
time stamps in the TZDB. The TZDB will list zone transitions in either
UTC or the zone's local time (which is then subject to DST offsets).
LibTimeZone did not handle the latter at all.

For example:

The following rule is in effect until November 18, 6PM UTC.

    America/Chicago -5:50:36 - LMT 1883 Nov 18 18:00u

The following rule is in effect until March 1, 2AM in Chicago time. But
at that time, a DST transition occurs, so the local time is actually
3AM.

    America/Chicago -6:00 Chicago C%sT 1936 Mar 1 2:00
2024-06-26 10:14:02 +02:00

145 lines
7.3 KiB
C++

/*
* Copyright (c) 2024, Tim Flynn <trflynn89@serenityos.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibTest/TestCase.h>
#include <AK/StringView.h>
#include <LibCore/Environment.h>
#include <LibUnicode/TimeZone.h>
class TimeZoneGuard {
public:
explicit TimeZoneGuard(StringView time_zone)
: m_time_zone(Core::Environment::get("TZ"sv))
{
MUST(Core::Environment::set("TZ"sv, time_zone, Core::Environment::Overwrite::Yes));
}
~TimeZoneGuard()
{
if (m_time_zone.has_value())
MUST(Core::Environment::set("TZ"sv, *m_time_zone, Core::Environment::Overwrite::Yes));
else
MUST(Core::Environment::unset("TZ"sv));
}
private:
Optional<StringView> m_time_zone;
};
TEST_CASE(current_time_zone)
{
{
TimeZoneGuard guard { "America/New_York"sv };
EXPECT_EQ(Unicode::current_time_zone(), "America/New_York"sv);
}
{
TimeZoneGuard guard { "ladybird"sv };
EXPECT_EQ(Unicode::current_time_zone(), "UTC"sv);
}
}
TEST_CASE(available_time_zones)
{
auto const& time_zones = Unicode::available_time_zones();
EXPECT(time_zones.contains_slow("UTC"sv));
EXPECT(!time_zones.contains_slow("EAT"sv));
}
TEST_CASE(available_time_zones_in_region)
{
{
auto time_zones = Unicode::available_time_zones_in_region("AD"sv);
EXPECT_EQ(time_zones, to_array({ "Europe/Andorra"_string }));
}
{
auto time_zones = Unicode::available_time_zones_in_region("ES"sv);
EXPECT_EQ(time_zones, to_array({ "Africa/Ceuta"_string, "Atlantic/Canary"_string, "Europe/Madrid"_string }));
}
}
TEST_CASE(resolve_primary_time_zone)
{
EXPECT_EQ(Unicode::resolve_primary_time_zone("UTC"sv), "Etc/UTC"sv);
EXPECT_EQ(Unicode::resolve_primary_time_zone("Asia/Katmandu"sv), "Asia/Kathmandu"sv);
EXPECT_EQ(Unicode::resolve_primary_time_zone("Australia/Canberra"sv), "Australia/Sydney"sv);
}
using enum Unicode::TimeZoneOffset::InDST;
static void test_offset(StringView time_zone, i64 time, Duration expected_offset, Unicode::TimeZoneOffset::InDST expected_in_dst)
{
auto actual_offset = Unicode::time_zone_offset(time_zone, AK::UnixDateTime::from_seconds_since_epoch(time));
VERIFY(actual_offset.has_value());
EXPECT_EQ(actual_offset->offset, expected_offset);
EXPECT_EQ(actual_offset->in_dst, expected_in_dst);
}
static constexpr Duration offset(i64 sign, i64 hours, i64 minutes, i64 seconds)
{
return Duration::from_seconds(sign * ((hours * 3600) + (minutes * 60) + seconds));
}
// Useful website to convert times in the TZDB (which sometimes are and aren't UTC) to UTC and the desired local time:
// https://www.epochconverter.com/#tools
//
// In the tests below, if only UTC time is shown as a comment, then the corresponding Rule change in the TZDB was specified
// as UTC. Otherwise, the TZDB time was local, and was converted to a UTC timestamp for that test.
TEST_CASE(time_zone_offset)
{
EXPECT(!Unicode::time_zone_offset("I don't exist"sv, {}).has_value());
test_offset("America/Chicago"sv, -2717647201, offset(-1, 5, 50, 36), No); // November 18, 1883 5:59:59 PM UTC
test_offset("America/Chicago"sv, -2717647200, offset(-1, 6, 0, 0), No); // November 18, 1883 6:00:00 PM UTC
test_offset("America/Chicago"sv, -1067788860, offset(-1, 6, 0, 0), No); // March 1, 1936 1:59:00 AM Chicago (March 1, 1936 7:59:00 AM UTC)
test_offset("America/Chicago"sv, -1067788800, offset(-1, 5, 0, 0), No); // March 1, 1936 3:00:00 AM Chicago (March 1, 1936 8:00:00 AM UTC)
test_offset("America/Chicago"sv, -1045414860, offset(-1, 5, 0, 0), No); // November 15, 1936 1:59:00 AM Chicago (November 15, 1936 6:59:00 AM UTC)
test_offset("America/Chicago"sv, -1045411200, offset(-1, 6, 0, 0), No); // November 15, 1936 2:00:00 AM Chicago (November 15, 1936 8:00:00 AM UTC)
test_offset("Europe/London"sv, -3852662326, offset(-1, 0, 1, 15), No); // November 30, 1847 11:59:59 PM London (December 1, 1847 12:01:14 AM UTC)
test_offset("Europe/London"sv, -3852662325, offset(+1, 0, 0, 0), No); // December 1, 1847 12:01:15 AM London (December 1, 1847 12:01:15 AM UTC)
test_offset("Europe/London"sv, -59004001, offset(+1, 0, 0, 0), No); // February 18, 1968 1:59:59 AM London (February 18, 1968 1:59:59 AM UTC)
test_offset("Europe/London"sv, -59004000, offset(+1, 1, 0, 0), Yes); // February 18, 1968 3:00:00 AM London (February 18, 1968 2:00:00 AM UTC)
test_offset("Europe/London"sv, 57722399, offset(+1, 1, 0, 0), No); // October 31, 1971 1:59:59 AM UTC
test_offset("Europe/London"sv, 57722400, offset(+1, 0, 0, 0), No); // October 31, 1971 2:00:00 AM UTC
test_offset("UTC"sv, -1641846268, offset(+1, 0, 00, 00), No);
test_offset("UTC"sv, 0, offset(+1, 0, 00, 00), No);
test_offset("UTC"sv, 1641846268, offset(+1, 0, 00, 00), No);
test_offset("Etc/GMT+4"sv, -1641846268, offset(-1, 4, 00, 00), No);
test_offset("Etc/GMT+5"sv, 0, offset(-1, 5, 00, 00), No);
test_offset("Etc/GMT+6"sv, 1641846268, offset(-1, 6, 00, 00), No);
test_offset("Etc/GMT-12"sv, -1641846268, offset(+1, 12, 00, 00), No);
test_offset("Etc/GMT-13"sv, 0, offset(+1, 13, 00, 00), No);
test_offset("Etc/GMT-14"sv, 1641846268, offset(+1, 14, 00, 00), No);
}
TEST_CASE(time_zone_offset_with_dst)
{
test_offset("America/New_York"sv, 1642576528, offset(-1, 5, 00, 00), No); // January 19, 2022 2:15:28 AM New York (January 19, 2022 7:15:28 AM UTC)
test_offset("America/New_York"sv, 1663568128, offset(-1, 4, 00, 00), Yes); // September 19, 2022 2:15:28 AM New York (September 19, 2022 6:15:28 AM UTC)
test_offset("America/New_York"sv, 1671471238, offset(-1, 5, 00, 00), No); // December 19, 2022 12:33:58 PM New York (December 19, 2022 5:33:58 PM UTC)
// Phoenix does not observe DST.
test_offset("America/Phoenix"sv, 1642583728, offset(-1, 7, 00, 00), No); // January 19, 2022 2:15:28 AM Phoenix (January 19, 2022 9:15:28 AM UTC)
test_offset("America/Phoenix"sv, 1663578928, offset(-1, 7, 00, 00), No); // September 19, 2022 2:15:28 AM Phoenix (September 19, 2022 9:15:28 AM UTC)
test_offset("America/Phoenix"sv, 1671478438, offset(-1, 7, 00, 00), No); // December 19, 2022 12:33:58 PM Phoenix (December 19, 2022 7:33:58 PM UTC)
// Moscow's observed DST changed several times in 1919.
test_offset("Europe/Moscow"sv, -1609459200, offset(+1, 3, 31, 19), Yes); // January 1, 1919 12:00:00 AM UTC
test_offset("Europe/Moscow"sv, -1596429079, offset(+1, 4, 31, 19), Yes); // June 1, 1919 12:00:00 AM Moscow (May 31, 1919 7:28:41 PM UTC)
test_offset("Europe/Moscow"sv, -1592625600, offset(+1, 4, 00, 00), Yes); // July 15, 1919 12:00:00 AM Moscow (July 14, 1919 8:00:00 PM UTC)
test_offset("Europe/Moscow"sv, -1589079600, offset(+1, 3, 00, 00), No); // August 25, 1919 12:00:00 AM Moscow (August 24, 1919 9:00:00 PM UTC)
// Paraguay begins the year in DST.
test_offset("America/Asuncion"sv, 1642569328, offset(-1, 3, 00, 00), Yes); // January 19, 2022 2:15:28 AM Asuncion (January 19, 2022 5:15:28 AM UTC)
test_offset("America/Asuncion"sv, 1663568128, offset(-1, 4, 00, 00), No); // September 19, 2022 2:15:28 AM Asuncion (September 19, 2022 6:15:28 AM UTC)
test_offset("America/Asuncion"sv, 1671464038, offset(-1, 3, 00, 00), Yes); // December 19, 2022 12:33:58 PM Asuncion (December 19, 2022 3:33:58 PM UTC)
}