;;; timefns-tests.el --- tests for timefns.c -*- lexical-binding: t -*-
;; Copyright (C) 2016-2025 Free Software Foundation, Inc.
;; This file is part of GNU Emacs.
;; GNU Emacs is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
;;; Code:
(require 'ert)
(defun timefns-tests--decode-time (look zone decoded-time)
(should (equal (decode-time look zone t) decoded-time))
(should (equal (decode-time look zone 'integer)
(cons (time-convert (car decoded-time) 'integer)
(cdr decoded-time)))))
;;; Check format-time-string and decode-time with various TZ settings.
;;; Use only POSIX-compatible TZ values, since the tests should work
;;; even if tzdb is not in use.
(ert-deftest format-time-string-with-zone ()
;; Don’t use (0 0 0 0) as the test case, as there are too many bugs
;; in MS-Windows (and presumably other) C libraries when formatting
;; time stamps near the Epoch of 1970-01-01 00:00:00 UTC, and this
;; test is for GNU Emacs, not for C runtimes. Instead, look before
;; you leap: "look" is the timestamp just before the first leap
;; second on 1972-06-30 23:59:60 UTC, so it should format to the
;; same string regardless of whether the underlying C library
;; ignores leap seconds, while avoiding circa-1970 glitches.
;;
;; Similarly, stick to the limited set of time zones that are
;; supported by both POSIX and MS-Windows: exactly 3 ASCII letters
;; in the abbreviation, and no DST.
(let ((format "%Y-%m-%d %H:%M:%S.%3N %z (%Z)"))
(dolist (look '((1202 22527 999999 999999)
(7879679999900 . 100000)
(78796799999999999999 . 1000000000000)))
;; UTC.
(let* ((look-ticks-hz (time-convert look t))
(hz (cdr look-ticks-hz))
(look-integer (time-convert look 'integer))
(sec (time-add (time-convert 59 hz)
(time-subtract look-ticks-hz
(time-convert look-integer hz)))))
(should (string-equal
(format-time-string "%Y-%m-%d %H:%M:%S.%3N %z" look t)
"1972-06-30 23:59:59.999 +0000"))
(timefns-tests--decode-time look t
(list sec 59 23 30 6 1972 5 nil 0))
;; "UTC0".
(should (string-equal
(format-time-string format look "UTC0")
"1972-06-30 23:59:59.999 +0000 (UTC)"))
(timefns-tests--decode-time look "UTC0"
(list sec 59 23 30 6 1972 5 nil 0))
;; Negative UTC offset, as a Lisp list.
(should (string-equal
(format-time-string format look '(-28800 "PST"))
"1972-06-30 15:59:59.999 -0800 (PST)"))
(timefns-tests--decode-time look '(-28800 "PST")
(list sec 59 15 30 6 1972 5 nil -28800))
;; Negative UTC offset, as a Lisp integer.
(should (string-equal
(format-time-string format look -28800)
;; MS-Windows build replaces unrecognizable TZ values,
;; such as "-08", with "ZZZ".
(if (eq system-type 'windows-nt)
"1972-06-30 15:59:59.999 -0800 (ZZZ)"
"1972-06-30 15:59:59.999 -0800 (-08)")))
(timefns-tests--decode-time look -28800
(list sec 59 15 30 6 1972 5 nil -28800))
;; Positive UTC offset that is not an hour multiple, as a string.
(should (string-equal
(format-time-string format look "IST-5:30")
"1972-07-01 05:29:59.999 +0530 (IST)"))
(timefns-tests--decode-time look "IST-5:30"
(list sec 29 5 1 7 1972 6 nil 19800))))))
(ert-deftest decode-then-encode-time ()
(let ((time-values (list 0 -2 1 0.0 -0.0 -2.0 1.0
most-negative-fixnum most-positive-fixnum
(1- most-negative-fixnum)
(1+ most-positive-fixnum)
'(0 1 0 0) '(1 0 0 0) '(-1 0 0 0)
'(123456789000000 . 1000000)
(cons (1+ most-positive-fixnum) 1000000000000)
(cons 1000000000000 (1+ most-positive-fixnum)))))
(dolist (a time-values)
(let* ((d (ignore-errors (decode-time a t t)))
(d-integer (ignore-errors (decode-time a t 'integer)))
(e (if d (encode-time d)))
(e-integer (if d-integer (encode-time d-integer))))
(should (or (not d) (time-equal-p a e)))
(should (or (not d-integer) (time-equal-p (time-convert a 'integer)
e-integer)))))))
;;; This should not dump core.
(ert-deftest format-time-string-with-outlandish-zone ()
(should (stringp
(format-time-string "%Y-%m-%d %H:%M:%S.%3N %z" nil
(concat (make-string 2048 ?X) "0")))))
(defun timefns-tests--have-leap-seconds ()
(string-equal (format-time-string "%Y-%m-%d %H:%M:%S" 78796800 t)
"1972-06-30 23:59:60"))
(ert-deftest format-time-string-with-bignum-on-32-bit ()
(should (or (string-equal
(format-time-string "%Y-%m-%d %H:%M:%S" (- (ash 1 31) 3600) t)
"2038-01-19 02:14:08")
(timefns-tests--have-leap-seconds))))
;;; Tests of format-time-string padding
(ert-deftest format-time-string-padding-minimal-deletes-unneeded-zeros ()
(let ((ref-time (encode-time '((123450 . 1000000) 0 0 15 2 2000 - - t))))
(should (equal (format-time-string "%-:::z" ref-time "FJT-12") "+12"))
(should (equal (format-time-string "%-N" ref-time t) "12345"))
(should (equal (format-time-string "%-6N" ref-time t) "12345"))
(should (equal (format-time-string "%-m" ref-time t) "2")))) ;not "02"
(ert-deftest format-time-string-padding-minimal-retains-needed-zeros ()
(let ((ref-time (encode-time '((3450 . 1000000) 0 0 20 10 2000 - - t))))
(should (equal (format-time-string "%-z" ref-time "IST-5:30") "+530"))
(should (equal (format-time-string "%-4z" ref-time "IST-5:30") "+530"))
(should (equal (format-time-string "%4z" ref-time "IST-5:30") "+530"))
(should (equal (format-time-string "%-N" ref-time t) "00345"))
(should (equal (format-time-string "%-3N" ref-time t) "003"))
(should (equal (format-time-string "%3N" ref-time t) "003"))
(should (equal (format-time-string "%-m" ref-time t) "10")) ;not "1"
(should (equal (format-time-string "%-1m" ref-time t) "10")) ;not "1"
(should (equal (format-time-string "%1m" ref-time t) "10")))) ;not "1"
(ert-deftest format-time-string-padding-spaces ()
(let ((ref-time (encode-time '((123000 . 1000000) 0 0 10 12 2000 - - t))))
(should (equal (format-time-string "%_7z" ref-time "CHA-12:45") " +1245"))
(should (equal (format-time-string "%_6N" ref-time t) "123 "))
(should (equal (format-time-string "%_9N" ref-time t) "123 "))
(should (equal (format-time-string "%_12N" ref-time t) "123 "))
(should (equal (format-time-string "%_m" ref-time t) "12"))
(should (equal (format-time-string "%_2m" ref-time t) "12"))
(should (equal (format-time-string "%_3m" ref-time t) " 12"))))
(ert-deftest format-time-string-padding-zeros-adds-on-insignificant-side ()
"Fractional seconds have a fixed place on the left,
and any padding must happen on the right. All other numbers have
a fixed place on the right and are padded on the left."
(let ((ref-time (encode-time '((123000 . 1000000) 0 0 10 12 2000 - - t))))
(should (equal (format-time-string "%3m" ref-time t) "012"))
(should (equal (format-time-string "%7z" ref-time "CHA-12:45") "+001245"))
(should (equal (format-time-string "%12N" ref-time t) "123000000000"))
(should (equal (format-time-string "%9N" ref-time t) "123000000"))
(should (equal (format-time-string "%6N" ref-time t) "123000"))))
(ert-deftest time-equal-p-nil-nil ()
(should (time-equal-p nil nil)))
(ert-deftest time-arith-tests ()
(let ((time-values (list 0 -1 1 0.0 -0.0 -1.0 1.0
most-negative-fixnum most-positive-fixnum
(1- most-negative-fixnum)
(1+ most-positive-fixnum)
1e1 -1e1 1e-1 -1e-1
1e8 -1e8 1e-8 -1e-8
1e9 -1e9 1e-9 -1e-9
1e10 -1e10 1e-10 -1e-10
1e16 -1e16 1e-16 -1e-16
1e37 -1e37 1e-37 -1e-37
'(0 0 0 1) '(0 0 1 0) '(0 1 0 0) '(1 0 0 0)
'(-1 0 0 0) '(1 2 3 4) '(-1 2 3 4)
'(-123456789 . 100000) '(123456789 . 1000000)
(cons (1+ most-positive-fixnum) 1000000000000)
(cons 1000000000000 (1+ most-positive-fixnum)))))
(dolist (a time-values)
(should-error (time-add a 'ouch))
(should-error (time-add 'ouch a))
(should-error (time-subtract a 'ouch))
(should-error (time-subtract 'ouch a))
(dolist (b time-values)
(let ((aa (time-subtract (time-add a b) b)))
(should (or (time-equal-p a aa) (and (floatp aa) (isnan aa)))))
(should (= 1 (+ (if (time-less-p a b) 1 0)
(if (time-equal-p a b) 1 0)
(if (time-less-p b a) 1 0)
(if (or (and (floatp a) (isnan a))
(and (floatp b) (isnan b)))
1 0))))
(should (or (not (time-less-p 0 b))
(time-less-p a (time-add a b))
(time-equal-p a (time-add a b))
(and (floatp (time-add a b)) (isnan (time-add a b)))))
(let ((x (float-time (time-add a b)))
(y (+ (float-time a) (float-time b))))
(should (or (and (isnan x) (isnan y))
(= x y)
(< 0.99 (/ x y) 1.01)
(< 0.99 (/ (- (float-time a)) (float-time b))
1.01))))))))
(ert-deftest time-rounding-tests ()
(should (time-equal-p 1e-13 (time-add 0 1e-13))))
(ert-deftest encode-time-dst-numeric-zone ()
"Check for Bug#35502."
(should (time-equal-p
(encode-time '(29 31 17 30 4 2019 2 t 7200))
'(23752 27217))))
(ert-deftest encode-time-alternate-apis ()
(let* ((time '(30 30 12 15 6 1970))
(time-1 (append time '(nil -1 nil)))
(etime (encode-time time)))
(should (time-equal-p etime (encode-time time-1)))
(should (time-equal-p etime (apply #'encode-time time)))
(should (time-equal-p etime (apply #'encode-time time-1)))
(should (time-equal-p etime (apply #'encode-time (append time '(nil)))))))
(ert-deftest float-time-precision ()
(should (= (float-time '(0 1 0 4025)) 1.000000004025))
(should (= (float-time '(1000000004025 . 1000000000000)) 1.000000004025))
(should (< 0 (float-time '(1 . 10000000000))))
(should (< (float-time '(-1 . 10000000000)) 0))
(let ((x 1.0))
(while (not (zerop x))
(dolist (multiplier '(-1.9 -1.5 -1.1 -1 1 1.1 1.5 1.9))
(let ((xmult (* x multiplier)))
(should (= xmult (float-time (time-convert xmult t))))))
(setq x (/ x 2))))
(let ((x 1.0))
(while (ignore-errors (time-convert x t))
(dolist (divisor '(-1.9 -1.5 -1.1 -1 1 1.1 1.5 1.9))
(let ((xdiv (/ x divisor)))
(should (= xdiv (float-time (time-convert xdiv t))))))
(setq x (* x 2)))))
(ert-deftest time-convert-forms ()
;; These computations involve numbers that should have exact
;; representations on any Emacs platform.
(dolist (time '(-86400 -1 0 1 86400))
(dolist (delta '(0 0.0 0.25 3.25 1000 1000.25))
(let ((time+ (+ time delta))
(time- (- time delta)))
(dolist (form '(nil t list 4 1000 1000000 1000000000))
(should (time-equal-p time (time-convert time form)))
(should (time-equal-p time- (time-convert time- form)))
(should (time-equal-p time+ (time-convert time+ form))))))))
(ert-deftest current-time-zone ()
(should (listp (current-time-zone)))
(should (= (length (current-time-zone)) 2)))
;;; timefns-tests.el ends here