Expand time-stamp unit tests to cover all formatting options

* time-stamp-tests.el: Expand unit tests to cover all formatting options.
These tests validate time-stamp-pattern formatting that has existed
since at least Emacs 22 (released in 2007).  The tests cover both
documented behavior and behavior implemented to support future migrations.

* time-stamp.el (time-stamp-string): Add a second argument (TIME) to
open a testing seam.  Have the unit tests call this public function.

* time-stamp.el (time-stamp-string, time-stamp-string-preprocess):
Remove the second pass through time-string--format.  (Previously both
functions called it.)  It was used only to handle "%", but this is now
handled by having time-stamp-string-preprocess not double it.
Not doubling the "%" in time-stamp-string-preprocess fixes the padding
of "%2%", which was discovered by the new unit tests to be wrong.

1 files changed, 284 insertions, 9 deletions

diff --git a/test/lisp/time-stamp-tests.el b/test/lisp/time-stamp-tests.el
index 3aa659e7a6d..165b4f13c2f 100644
--- a/test/lisp/time-stamp-tests.el
+++ b/test/lisp/time-stamp-tests.el
@@ -20,17 +20,292 @@
 ;;; Code:
 
 (require 'ert)
+(eval-when-compile (require 'cl-lib))
 (require 'time-stamp)
 
-(defun test-stamp (ts-format time)
-  (time-stamp--format (time-stamp-string-preprocess ts-format time) time))
+(defmacro with-time-stamp-test-env (&rest body)
+  "Evaluates BODY with some standard time-stamp test variables bound."
+  `(let ((user-login-name "test-logname")
+         (user-full-name "Time Stamp Tester")
+         (buffer-file-name "/emacs/test/time-stamped-file")
+         (mail-host-address "test-mail-host-name")
+         (ref-time '(17337 16613))     ;Monday, Jan 2, 2006, 3:04:05 PM
+         (ref-time2 '(22574 61591))    ;Friday, Nov 18, 2016, 12:14:15 PM
+         (ref-time3 '(21377 23973 123456)) ;Sun, May 25, 2014, 03:04:05.123456am
+         (time-stamp-time-zone t))     ;use UTC
+     (cl-letf (((symbol-function 'time-stamp-conv-warn)
+                (lambda (old-format _new)
+                  (ert-fail
+                   (format "Unexpected format warning for '%s'" old-format))))
+               ((symbol-function 'system-name)
+                (lambda () "test-system-name.example.org")))
+       ;; Not all reference times are used in all tests;
+       ;; suppress the byte compiler's "unused" warning.
+       (list ref-time ref-time2 ref-time3)
+       ,@body)))
+(put 'with-time-stamp-test-env 'lisp-indent-hook 'defun)
 
-(ert-deftest test-time-stamp ()
-  (let ((user-login-name "foo")
-        (time-stamp-time-zone t)
-        (time '(23847 24475 657815 318000))
-        (format "%:y-%02m-%02d %02H:%02M:%02S %u"))
-    (should (equal (test-stamp format time)
-                   "2019-07-11 16:11:07 foo"))))
+(defmacro time-stamp-should-warn (form)
+  "Similar to `should' but verifies that a format warning is generated."
+  `(let ((warning-count 0))
+     (cl-letf (((symbol-function 'time-stamp-conv-warn)
+                (lambda (_old _new)
+                  (setq warning-count (1+ warning-count)))))
+       (should ,form)
+       (if (not (= warning-count 1))
+           (ert-fail (format "Should have warned about format: %S" ',form))))))
+
+;;; Tests:
+
+(ert-deftest time-stamp-test-day-of-week-documented ()
+  "Test documented time-stamp formats for day of week."
+  (with-time-stamp-test-env
+    (should (equal (time-stamp-string "%3a" ref-time) "Mon"))
+    (should (equal (time-stamp-string "%3A" ref-time) "MON"))
+    (should (equal (time-stamp-string "%:a" ref-time) "Monday"))
+    (should (equal (time-stamp-string "%#A" ref-time) "MONDAY"))
+    (should (equal (time-stamp-string "%3a" ref-time2) "Fri"))
+    (should (equal (time-stamp-string "%3A" ref-time2) "FRI"))
+    (should (equal (time-stamp-string "%:a" ref-time2) "Friday"))
+    (should (equal (time-stamp-string "%#A" ref-time2) "FRIDAY"))))
+
+(ert-deftest time-stamp-test-day-of-week-future ()
+  "Test implemented but as yet undocumented time-stamp formats for day of week."
+  (with-time-stamp-test-env
+    (should (equal (time-stamp-string "%#a" ref-time) "MON"))
+    (should (equal (time-stamp-string "%:A" ref-time) "Monday"))
+    (should (equal (time-stamp-string "%#a" ref-time2) "FRI"))
+    (should (equal (time-stamp-string "%:A" ref-time2) "Friday"))))
+
+(ert-deftest time-stamp-test-day-of-week-volatile-warns ()
+  "Test time-stamp formats for day of week that will change.
+Test that each generates a warning."
+  (with-time-stamp-test-env
+    (time-stamp-should-warn (equal
+                            (time-stamp-string "%a" ref-time) "Monday"))
+    (time-stamp-should-warn (equal
+                             (time-stamp-string "%A" ref-time) "MONDAY"))))
+
+(ert-deftest time-stamp-test-month-name-documented ()
+  "Test documented time-stamp formats for month name."
+  (with-time-stamp-test-env
+    (should (equal (time-stamp-string "%3b" ref-time) "Jan"))
+    (should (equal (time-stamp-string "%3B" ref-time) "JAN"))
+    (should (equal (time-stamp-string "%:b" ref-time) "January"))
+    (should (equal (time-stamp-string "%#B" ref-time) "JANUARY"))))
+
+(ert-deftest time-stamp-test-month-name-future ()
+  "Test implemented but as yet undocumented time-stamp formats for month name."
+  (with-time-stamp-test-env
+    (should (equal (time-stamp-string "%#b" ref-time) "JAN"))
+    (should (equal (time-stamp-string "%:B" ref-time) "January"))))
+
+(ert-deftest time-stamp-test-month-name-volatile-warns ()
+  "Test time-stamp formats for month name that will change.
+Test that each generates a warning."
+  (with-time-stamp-test-env
+    (time-stamp-should-warn (equal
+                             (time-stamp-string "%b" ref-time) "January"))
+    (time-stamp-should-warn (equal
+                             (time-stamp-string "%B" ref-time) "JANUARY"))))
+
+(ert-deftest time-stamp-test-day-of-month ()
+  "Test time-stamp formats for day of month."
+  (with-time-stamp-test-env
+    ;; documented 1-digit
+    (should (equal (time-stamp-string "%:d" ref-time) "2"))
+    (should (equal (time-stamp-string "%2d" ref-time) " 2"))
+    (should (equal (time-stamp-string "%02d" ref-time) "02"))
+    ;; documented 2-digit
+    (should (equal (time-stamp-string "%:d" ref-time2) "18"))
+    (should (equal (time-stamp-string "%2d" ref-time2) "18"))
+    (should (equal (time-stamp-string "%02d" ref-time2) "18"))
+    ;; undocumented future formats
+    (should (equal (time-stamp-string "%1d" ref-time) "2"))
+    (should (equal (time-stamp-string "%1d" ref-time2) "18"))
+    ;; changing formats
+    (time-stamp-should-warn (equal (time-stamp-string "%d" ref-time) "2"))
+    (time-stamp-should-warn (equal (time-stamp-string "%_d" ref-time) "2"))))
+
+(ert-deftest time-stamp-test-hours-24 ()
+  "Test time-stamp formats for hour on a 24-hour clock."
+  (with-time-stamp-test-env
+    ;; documented PM
+    (should (equal (time-stamp-string "%:H" ref-time) "15"))
+    (should (equal (time-stamp-string "%2H" ref-time) "15"))
+    (should (equal (time-stamp-string "%02H" ref-time) "15"))
+    ;; documented AM
+    (should (equal (time-stamp-string "%:H" ref-time2) "12"))
+    (should (equal (time-stamp-string "%2H" ref-time2) "12"))
+    (should (equal (time-stamp-string "%02H" ref-time2) "12"))
+    ;; documented 1-digit
+    (should (equal (time-stamp-string "%:H" ref-time3) "3"))
+    (should (equal (time-stamp-string "%2H" ref-time3) " 3"))
+    (should (equal (time-stamp-string "%02H" ref-time3) "03"))
+    ;; undocumented future formats
+    (should (equal (time-stamp-string "%1H" ref-time) "15"))
+    (should (equal (time-stamp-string "%1H" ref-time2) "12"))
+    (should (equal (time-stamp-string "%1H" ref-time3) "3"))
+    ;; changing formats
+    (time-stamp-should-warn (equal (time-stamp-string "%H" ref-time) "15"))
+    (time-stamp-should-warn (equal (time-stamp-string "%_H" ref-time) "15"))))
+
+(ert-deftest time-stamp-test-hours-12 ()
+  "Test time-stamp formats for hour on a 12-hour clock."
+  (with-time-stamp-test-env
+    ;; documented 1-digit, PM
+    (should (equal (time-stamp-string "%:I" ref-time) "3"))
+    (should (equal (time-stamp-string "%2I" ref-time) " 3"))
+    (should (equal (time-stamp-string "%02I" ref-time) "03"))
+    ;; documented 2-digit
+    (should (equal (time-stamp-string "%:I" ref-time2) "12"))
+    (should (equal (time-stamp-string "%2I" ref-time2) "12"))
+    (should (equal (time-stamp-string "%02I" ref-time2) "12"))
+    ;; undocumented future formats
+    (should (equal (time-stamp-string "%1I" ref-time) "3"))
+    (should (equal (time-stamp-string "%1I" ref-time2) "12"))
+    ;; changing formats
+    (time-stamp-should-warn (equal (time-stamp-string "%I" ref-time) "3"))
+    (time-stamp-should-warn (equal (time-stamp-string "%_I" ref-time) "3"))))
+
+(ert-deftest time-stamp-test-month-number ()
+  "Test time-stamp formats for month number."
+  (with-time-stamp-test-env
+    ;; documented 1-digit
+    (should (equal (time-stamp-string "%:m" ref-time) "1"))
+    (should (equal (time-stamp-string "%2m" ref-time) " 1"))
+    (should (equal (time-stamp-string "%02m" ref-time) "01"))
+    ;; documented 2-digit
+    (should (equal (time-stamp-string "%:m" ref-time2) "11"))
+    (should (equal (time-stamp-string "%2m" ref-time2) "11"))
+    (should (equal (time-stamp-string "%02m" ref-time2) "11"))
+    ;; undocumented future formats
+    (should (equal (time-stamp-string "%1m" ref-time) "1"))
+    (should (equal (time-stamp-string "%1m" ref-time2) "11"))
+    ;; changing formats
+    (time-stamp-should-warn (equal (time-stamp-string "%m" ref-time) "1"))
+    (time-stamp-should-warn (equal (time-stamp-string "%_m" ref-time) "1"))))
+
+(ert-deftest time-stamp-test-minute ()
+  "Test time-stamp formats for minute."
+  (with-time-stamp-test-env
+    ;; documented 1-digit
+    (should (equal (time-stamp-string "%:M" ref-time) "4"))
+    (should (equal (time-stamp-string "%2M" ref-time) " 4"))
+    (should (equal (time-stamp-string "%02M" ref-time) "04"))
+    ;; documented 2-digit
+    (should (equal (time-stamp-string "%:M" ref-time2) "14"))
+    (should (equal (time-stamp-string "%2M" ref-time2) "14"))
+    (should (equal (time-stamp-string "%02M" ref-time2) "14"))
+    ;; undocumented future formats
+    (should (equal (time-stamp-string "%1M" ref-time) "4"))
+    (should (equal (time-stamp-string "%1M" ref-time2) "14"))
+    ;; changing formats
+    (time-stamp-should-warn (equal (time-stamp-string "%M" ref-time) "4"))
+    (time-stamp-should-warn (equal (time-stamp-string "%_M" ref-time) "4"))))
+
+(ert-deftest time-stamp-test-second ()
+  "Test time-stamp formats for second."
+  (with-time-stamp-test-env
+    ;; documented 1-digit
+    (should (equal (time-stamp-string "%:S" ref-time) "5"))
+    (should (equal (time-stamp-string "%2S" ref-time) " 5"))
+    (should (equal (time-stamp-string "%02S" ref-time) "05"))
+    ;; documented 2-digit
+    (should (equal (time-stamp-string "%:S" ref-time2) "15"))
+    (should (equal (time-stamp-string "%2S" ref-time2) "15"))
+    (should (equal (time-stamp-string "%02S" ref-time2) "15"))
+    ;; undocumented future formats
+    (should (equal (time-stamp-string "%1S" ref-time) "5"))
+    (should (equal (time-stamp-string "%1S" ref-time2) "15"))
+    ;; changing formats
+    (time-stamp-should-warn (equal (time-stamp-string "%S" ref-time) "5"))
+    (time-stamp-should-warn (equal (time-stamp-string "%_S" ref-time) "5"))))
+
+(ert-deftest time-stamp-test-am-pm ()
+  "Test time-stamp formats for AM and PM strings."
+  (with-time-stamp-test-env
+    ;; documented
+    (should (equal (time-stamp-string "%#p" ref-time) "pm"))
+    (should (equal (time-stamp-string "%P" ref-time) "PM"))
+    (should (equal (time-stamp-string "%#p" ref-time3) "am"))
+    (should (equal (time-stamp-string "%P" ref-time3) "AM"))
+    ;; changing
+    (time-stamp-should-warn (equal (time-stamp-string "%p" ref-time) "pm"))))
+
+(ert-deftest time-stamp-test-day-number-in-week ()
+  "Test time-stamp formats for day number in week."
+  (with-time-stamp-test-env
+    (should (equal (time-stamp-string "%w" ref-time) "1"))
+    (should (equal (time-stamp-string "%w" ref-time2) "5"))
+    (should (equal (time-stamp-string "%w" ref-time3) "0"))))
+
+(ert-deftest time-stamp-test-year ()
+  "Test time-stamp formats for year."
+  (with-time-stamp-test-env
+    ;; documented
+    (should (equal (time-stamp-string "%02y" ref-time) "06"))
+    (should (equal (time-stamp-string "%:y" ref-time) "2006"))
+    ;; undocumented future formats
+    (should (equal (time-stamp-string "%Y" ref-time) "2006"))
+    ;; changing
+    (time-stamp-should-warn (equal (time-stamp-string "%y" ref-time) "2006"))))
+
+(ert-deftest time-stamp-test-time-zone ()
+  "Test time-stamp formats for time zone."
+  (with-time-stamp-test-env
+    ;; documented
+    (should (equal (time-stamp-string "%z" ref-time) "gmt"))
+    (should (equal (time-stamp-string "%Z" ref-time) "GMT"))
+    ;; undocumented future formats
+    (should (equal (time-stamp-string "%#Z" ref-time) "gmt"))))
+
+(ert-deftest time-stamp-test-non-date-conversions ()
+  "Test time-stamp formats for non-date items."
+  (with-time-stamp-test-env
+    ;; documented
+    (should (equal (time-stamp-string "%%" ref-time) "%")) ;% last char
+    (should (equal (time-stamp-string "%%P" ref-time) "%P")) ;% not last char
+    (should (equal (time-stamp-string "%f" ref-time) "time-stamped-file"))
+    (should (equal
+             (time-stamp-string "%F" ref-time) "/emacs/test/time-stamped-file"))
+    (should
+     (equal (time-stamp-string "%s" ref-time) "test-system-name.example.org"))
+    (should (equal (time-stamp-string "%u" ref-time) "test-logname"))
+    (should (equal (time-stamp-string "%U" ref-time) "Time Stamp Tester"))
+    (should (equal (time-stamp-string "%h" ref-time) "test-mail-host-name"))
+    ;; undocumented
+    (should (equal (time-stamp-string "%L" ref-time) "Time Stamp Tester"))
+    (should (equal (time-stamp-string "%l" ref-time) "test-logname"))
+    (should (equal
+             (time-stamp-string "%Q" ref-time) "test-system-name.example.org"))
+    (should (equal
+             (time-stamp-string "%q" ref-time) "test-system-name"))))
+
+(ert-deftest time-stamp-test-ignored-modifiers ()
+  "Test additional args allowed (but ignored) to allow for future expansion."
+  (with-time-stamp-test-env
+    ;; allowed modifiers
+    (should (equal (time-stamp-string "%.,@-+_ ^(stuff)P" ref-time3) "AM"))
+    ;; not all punctuation is allowed
+    (should-not (equal (time-stamp-string "%&P" ref-time3) "AM"))))
+
+(ert-deftest time-stamp-test-non-conversions ()
+  "Test that without a %, the text is copied literally."
+  (with-time-stamp-test-env
+    (should (equal (time-stamp-string "No percent" ref-time) "No percent"))))
+
+(ert-deftest time-stamp-test-string-width ()
+  "Test time-stamp string width modifiers."
+  (with-time-stamp-test-env
+    ;; strings truncate on the right or are blank-padded on the left
+    (should (equal (time-stamp-string "%0P" ref-time3) ""))
+    (should (equal (time-stamp-string "%1P" ref-time3) "A"))
+    (should (equal (time-stamp-string "%2P" ref-time3) "AM"))
+    (should (equal (time-stamp-string "%3P" ref-time3) " AM"))
+    (should (equal (time-stamp-string "%0%" ref-time3) ""))
+    (should (equal (time-stamp-string "%1%" ref-time3) "%"))
+    (should (equal (time-stamp-string "%2%" ref-time3) " %"))
+    (should (equal (time-stamp-string "%#3a" ref-time3) "SUN"))))
 
 ;;; time-stamp-tests.el ends here