Add 94 tests across 10 new test files and fix 2 bugs

New test coverage for previously untested functions:
- filter-day-wide-events, time utilities, day-wide time matching
- make-tooltip, event-is-today, get-tags, done-keywords-predicate
- extract-title, propertize-modeline-string, warn-persistent-failures
- log-silently

Bug fixes discovered by new tests:
- Fix pluralization in no-events tooltip ("1 hours" -> "1 hour", etc.)
- Fix chime--get-tags returning ("") instead of nil for untagged headings

1 files changed, 174 insertions, 0 deletions

diff --git a/tests/test-chime-time-utilities.el b/tests/test-chime-time-utilities.el
new file mode 100644
index 0000000..06e1a3b
--- /dev/null
+++ b/tests/test-chime-time-utilities.el
@@ -0,0 +1,174 @@
+;;; test-chime-time-utilities.el --- Tests for time utility functions -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2024-2026 Craig Jennings
+
+;; Author: Craig Jennings <c@cjennings.net>
+
+;; This program 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.
+
+;; This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; Unit tests for chime time utility functions:
+;; - chime-get-minutes-into-day
+;; - chime-get-hours-minutes-from-time
+;; - chime-set-hours-minutes-for-time
+
+;;; Code:
+
+;; Initialize package system for batch mode
+(when noninteractive
+  (package-initialize))
+
+(require 'ert)
+
+;; Load dependencies required by chime
+(require 'dash)
+(require 'alert)
+(require 'async)
+(require 'org-agenda)
+
+;; Load chime from parent directory
+(load (expand-file-name "../chime.el") nil t)
+
+;; Load test utilities
+(require 'testutil-general (expand-file-name "testutil-general.el"))
+(require 'testutil-time (expand-file-name "testutil-time.el"))
+
+;;;; Tests for chime-get-minutes-into-day
+
+;;; Normal Cases
+
+(ert-deftest test-chime-get-minutes-into-day-noon ()
+  "Noon (12:00) should be 720 minutes into the day."
+  (should (= 720 (chime-get-minutes-into-day "12:00"))))
+
+(ert-deftest test-chime-get-minutes-into-day-afternoon ()
+  "14:30 should be 870 minutes into the day."
+  (should (= 870 (chime-get-minutes-into-day "14:30"))))
+
+(ert-deftest test-chime-get-minutes-into-day-morning ()
+  "8:00 should be 480 minutes into the day."
+  (should (= 480 (chime-get-minutes-into-day "8:00"))))
+
+;;; Boundary Cases
+
+(ert-deftest test-chime-get-minutes-into-day-midnight ()
+  "Midnight (0:00) should be 0 minutes into the day."
+  (should (= 0 (chime-get-minutes-into-day "0:00"))))
+
+(ert-deftest test-chime-get-minutes-into-day-end-of-day ()
+  "23:59 should be 1439 minutes into the day."
+  (should (= 1439 (chime-get-minutes-into-day "23:59"))))
+
+(ert-deftest test-chime-get-minutes-into-day-one-minute-past-midnight ()
+  "0:01 should be 1 minute into the day."
+  (should (= 1 (chime-get-minutes-into-day "0:01"))))
+
+;;;; Tests for chime-get-hours-minutes-from-time
+
+;;; Normal Cases
+
+(ert-deftest test-chime-get-hours-minutes-afternoon ()
+  "14:30 should return (14 30)."
+  (should (equal '(14 30) (chime-get-hours-minutes-from-time "14:30"))))
+
+(ert-deftest test-chime-get-hours-minutes-morning ()
+  "8:00 should return (8 0)."
+  (should (equal '(8 0) (chime-get-hours-minutes-from-time "8:00"))))
+
+(ert-deftest test-chime-get-hours-minutes-with-minutes ()
+  "9:45 should return (9 45)."
+  (should (equal '(9 45) (chime-get-hours-minutes-from-time "9:45"))))
+
+;;; Boundary Cases
+
+(ert-deftest test-chime-get-hours-minutes-midnight ()
+  "0:00 should return (0 0)."
+  (should (equal '(0 0) (chime-get-hours-minutes-from-time "0:00"))))
+
+(ert-deftest test-chime-get-hours-minutes-exact-hour ()
+  "10:00 should return (10 0) with no leftover minutes."
+  (should (equal '(10 0) (chime-get-hours-minutes-from-time "10:00"))))
+
+(ert-deftest test-chime-get-hours-minutes-end-of-day ()
+  "23:59 should return (23 59)."
+  (should (equal '(23 59) (chime-get-hours-minutes-from-time "23:59"))))
+
+(ert-deftest test-chime-get-hours-minutes-noon ()
+  "12:00 should return (12 0)."
+  (should (equal '(12 0) (chime-get-hours-minutes-from-time "12:00"))))
+
+;;;; Tests for chime-set-hours-minutes-for-time
+
+;;; Normal Cases
+
+(ert-deftest test-chime-set-hours-minutes-preserves-date ()
+  "Setting hours/minutes should preserve the date."
+  (let* ((base (test-time-tomorrow-at 10 0))
+         (result (chime-set-hours-minutes-for-time base 14 30))
+         (decoded (decode-time result))
+         (base-decoded (decode-time base)))
+    ;; Date should be the same
+    (should (= (decoded-time-day base-decoded) (decoded-time-day decoded)))
+    (should (= (decoded-time-month base-decoded) (decoded-time-month decoded)))
+    (should (= (decoded-time-year base-decoded) (decoded-time-year decoded)))
+    ;; Time should be changed
+    (should (= 14 (decoded-time-hour decoded)))
+    (should (= 30 (decoded-time-minute decoded)))
+    (should (= 0 (decoded-time-second decoded)))))
+
+(ert-deftest test-chime-set-hours-minutes-changes-time ()
+  "Setting different hours/minutes should produce different time."
+  (let* ((base (test-time-tomorrow-at 10 0))
+         (result (chime-set-hours-minutes-for-time base 15 45))
+         (decoded (decode-time result)))
+    (should (= 15 (decoded-time-hour decoded)))
+    (should (= 45 (decoded-time-minute decoded)))))
+
+;;; Boundary Cases
+
+(ert-deftest test-chime-set-hours-minutes-midnight ()
+  "Setting to midnight (0, 0) should work."
+  (let* ((base (test-time-tomorrow-at 10 0))
+         (result (chime-set-hours-minutes-for-time base 0 0))
+         (decoded (decode-time result)))
+    (should (= 0 (decoded-time-hour decoded)))
+    (should (= 0 (decoded-time-minute decoded)))))
+
+(ert-deftest test-chime-set-hours-minutes-end-of-day ()
+  "Setting to 23:59 should work."
+  (let* ((base (test-time-tomorrow-at 10 0))
+         (result (chime-set-hours-minutes-for-time base 23 59))
+         (decoded (decode-time result)))
+    (should (= 23 (decoded-time-hour decoded)))
+    (should (= 59 (decoded-time-minute decoded)))))
+
+(ert-deftest test-chime-set-hours-minutes-roundtrip ()
+  "Extracting hours/minutes and setting them back should produce same time-of-day."
+  (let* ((base (test-time-tomorrow-at 14 30))
+         (hm (chime-get-hours-minutes-from-time "14:30"))
+         (result (chime-set-hours-minutes-for-time base (car hm) (cadr hm)))
+         (decoded (decode-time result)))
+    (should (= 14 (decoded-time-hour decoded)))
+    (should (= 30 (decoded-time-minute decoded)))))
+
+(ert-deftest test-chime-set-hours-minutes-seconds-always-zero ()
+  "Seconds should always be set to 0 regardless of base time."
+  (let* ((base (test-time-now)) ;; may have non-zero seconds internally
+         (result (chime-set-hours-minutes-for-time base 10 0))
+         (decoded (decode-time result)))
+    (should (= 0 (decoded-time-second decoded)))))
+
+(provide 'test-chime-time-utilities)
+;;; test-chime-time-utilities.el ends here