91 lines
3.2 KiB
Rust
91 lines
3.2 KiB
Rust
//! Tests for the leap second table.
|
||
//!
|
||
//! 闰秒表的测试。
|
||
|
||
use apsis_leap::{
|
||
LEAP_SECONDS, TABLE_COVERS_FROM_MJD, TAI_MINUS_UTC_AFTER_LAST_ENTRY, mjd_from_ymd,
|
||
};
|
||
|
||
#[test]
|
||
fn table_is_ordered_and_monotonic() {
|
||
let mut previous = f64::NEG_INFINITY;
|
||
for entry in LEAP_SECONDS {
|
||
assert!(
|
||
(1..=12).contains(&entry.month),
|
||
"month out of range: {entry:?}"
|
||
);
|
||
assert!((1..=31).contains(&entry.day), "day out of range: {entry:?}");
|
||
let mjd = entry.effective_mjd();
|
||
assert!(mjd > previous, "table is not ordered at {entry:?}");
|
||
previous = mjd;
|
||
}
|
||
}
|
||
|
||
#[test]
|
||
fn every_entry_increases_the_offset_by_one_second() {
|
||
// The table starts at the inherited offset of ten seconds and every
|
||
// later announcement inserted exactly one second.
|
||
// 该表始于继承而来的十秒偏移，其后每次宣布都恰好插入一秒。
|
||
assert_eq!(LEAP_SECONDS[0].tai_minus_utc, 10.0);
|
||
for pair in LEAP_SECONDS.windows(2) {
|
||
let (earlier, later) = (pair[0], pair[1]);
|
||
assert!(
|
||
(later.tai_minus_utc - earlier.tai_minus_utc - 1.0).abs() < f64::EPSILON,
|
||
"offset step is not one second between {earlier:?} and {later:?}"
|
||
);
|
||
}
|
||
}
|
||
|
||
#[test]
|
||
fn table_extremes_match_the_announced_values() {
|
||
assert_eq!(LEAP_SECONDS[0].effective_mjd(), 41_317.0);
|
||
let last = LEAP_SECONDS[LEAP_SECONDS.len() - 1];
|
||
assert_eq!(last.year, 2017);
|
||
assert_eq!(last.month, 1);
|
||
assert_eq!(last.day, 1);
|
||
assert_eq!(last.tai_minus_utc, 37.0);
|
||
assert_eq!(last.effective_mjd(), 57_754.0);
|
||
}
|
||
|
||
#[test]
|
||
fn table_contains_every_announcement_since_1972() {
|
||
// Twenty seven leap seconds were introduced between 1972 and 2017
|
||
// inclusive of the initial 1972-01-01 entry.
|
||
// 1972 年到 2017 年间引入了二十七个闰秒，含 1972-01-01 的初项。
|
||
assert_eq!(LEAP_SECONDS.len(), 28);
|
||
}
|
||
|
||
#[test]
|
||
fn coverage_constants_match_the_table_boundaries() {
|
||
assert_eq!(TABLE_COVERS_FROM_MJD, LEAP_SECONDS[0].effective_mjd());
|
||
assert_eq!(TAI_MINUS_UTC_AFTER_LAST_ENTRY, 37.0);
|
||
}
|
||
|
||
#[test]
|
||
fn known_calendar_dates_map_to_known_modified_julian_dates() {
|
||
// MJD 0 is the start of 1858-11-17.
|
||
// MJD 0 是 1858-11-17 的起点。
|
||
assert_eq!(mjd_from_ymd(1858, 11, 17), 0.0);
|
||
// The calendar day of J2000.0 is MJD 51544.
|
||
// J2000.0 的日历日是 MJD 51544。
|
||
assert_eq!(mjd_from_ymd(2000, 1, 1), 51_544.0);
|
||
// The Unix epoch is MJD 40587.
|
||
// Unix 历元是 MJD 40587。
|
||
assert_eq!(mjd_from_ymd(1970, 1, 1), 40_587.0);
|
||
// The last leap second.
|
||
// 最后一个闰秒。
|
||
assert_eq!(mjd_from_ymd(2017, 1, 1), 57_754.0);
|
||
assert_eq!(mjd_from_ymd(2024, 1, 1), 60_310.0);
|
||
}
|
||
|
||
#[test]
|
||
fn calendar_conversion_handles_leap_days_and_month_ends() {
|
||
// 2000 is a leap year, 1900 is not.
|
||
// 2000 年是闰年，1900 年不是。
|
||
assert_eq!(mjd_from_ymd(2000, 3, 1) - mjd_from_ymd(2000, 2, 1), 29.0);
|
||
assert_eq!(mjd_from_ymd(1900, 3, 1) - mjd_from_ymd(1900, 2, 1), 28.0);
|
||
// Consecutive month ends are one day apart.
|
||
// 连续的月末相隔一天。
|
||
assert_eq!(mjd_from_ymd(2024, 3, 1) - mjd_from_ymd(2024, 2, 29), 1.0);
|
||
}
|