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, 165 insertions, 0 deletions

diff --git a/tests/test-chime-warn-persistent-failures.el b/tests/test-chime-warn-persistent-failures.el
new file mode 100644
index 0000000..e24132a
--- /dev/null
+++ b/tests/test-chime-warn-persistent-failures.el
@@ -0,0 +1,165 @@
+;;; test-chime-warn-persistent-failures.el --- Tests for chime--maybe-warn-persistent-failures -*- 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--maybe-warn-persistent-failures function.
+;; This function warns the user when consecutive async failures reach
+;; the configured threshold. It should warn exactly once at the threshold.
+
+;;; 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)
+
+;;; Setup and Teardown
+
+(defun test-warn-failures-setup ()
+  "Setup function."
+  (setq chime--consecutive-async-failures 0)
+  (setq chime-max-consecutive-failures 5))
+
+(defun test-warn-failures-teardown ()
+  "Teardown function."
+  (setq chime--consecutive-async-failures 0)
+  (setq chime-max-consecutive-failures 5))
+
+;;; Normal Cases
+
+(ert-deftest test-chime-warn-failures-warns-at-threshold ()
+  "Should call display-warning when failures reach the threshold."
+  (test-warn-failures-setup)
+  (unwind-protect
+      (let ((warned nil))
+        (setq chime--consecutive-async-failures 5)
+        (setq chime-max-consecutive-failures 5)
+        (cl-letf (((symbol-function 'display-warning)
+                   (lambda (_type _msg &rest _args) (setq warned t))))
+          (chime--maybe-warn-persistent-failures)
+          (should warned)))
+    (test-warn-failures-teardown)))
+
+(ert-deftest test-chime-warn-failures-no-warn-below-threshold ()
+  "Should NOT warn when failures are below the threshold."
+  (test-warn-failures-setup)
+  (unwind-protect
+      (let ((warned nil))
+        (setq chime--consecutive-async-failures 4)
+        (setq chime-max-consecutive-failures 5)
+        (cl-letf (((symbol-function 'display-warning)
+                   (lambda (_type _msg &rest _args) (setq warned t))))
+          (chime--maybe-warn-persistent-failures)
+          (should-not warned)))
+    (test-warn-failures-teardown)))
+
+(ert-deftest test-chime-warn-failures-no-warn-above-threshold ()
+  "Should NOT warn again after exceeding the threshold (warns once)."
+  (test-warn-failures-setup)
+  (unwind-protect
+      (let ((warned nil))
+        (setq chime--consecutive-async-failures 6)
+        (setq chime-max-consecutive-failures 5)
+        (cl-letf (((symbol-function 'display-warning)
+                   (lambda (_type _msg &rest _args) (setq warned t))))
+          (chime--maybe-warn-persistent-failures)
+          (should-not warned)))
+    (test-warn-failures-teardown)))
+
+(ert-deftest test-chime-warn-failures-message-includes-count ()
+  "Warning message should include the failure count."
+  (test-warn-failures-setup)
+  (unwind-protect
+      (let ((warning-msg nil))
+        (setq chime--consecutive-async-failures 5)
+        (setq chime-max-consecutive-failures 5)
+        (cl-letf (((symbol-function 'display-warning)
+                   (lambda (_type msg &rest _args) (setq warning-msg msg))))
+          (chime--maybe-warn-persistent-failures)
+          (should warning-msg)
+          (should (string-match-p "5" warning-msg))))
+    (test-warn-failures-teardown)))
+
+(ert-deftest test-chime-warn-failures-severity-is-warning ()
+  "Warning should use :warning severity."
+  (test-warn-failures-setup)
+  (unwind-protect
+      (let ((warning-severity nil))
+        (setq chime--consecutive-async-failures 5)
+        (setq chime-max-consecutive-failures 5)
+        (cl-letf (((symbol-function 'display-warning)
+                   (lambda (_type _msg &rest args) (setq warning-severity (car args)))))
+          (chime--maybe-warn-persistent-failures)
+          (should (eq :warning warning-severity))))
+    (test-warn-failures-teardown)))
+
+;;; Boundary Cases
+
+(ert-deftest test-chime-warn-failures-threshold-of-1 ()
+  "Threshold of 1 should warn on the very first failure."
+  (test-warn-failures-setup)
+  (unwind-protect
+      (let ((warned nil))
+        (setq chime--consecutive-async-failures 1)
+        (setq chime-max-consecutive-failures 1)
+        (cl-letf (((symbol-function 'display-warning)
+                   (lambda (_type _msg &rest _args) (setq warned t))))
+          (chime--maybe-warn-persistent-failures)
+          (should warned)))
+    (test-warn-failures-teardown)))
+
+(ert-deftest test-chime-warn-failures-threshold-of-0-disables ()
+  "Threshold of 0 should disable warnings entirely."
+  (test-warn-failures-setup)
+  (unwind-protect
+      (let ((warned nil))
+        (setq chime--consecutive-async-failures 0)
+        (setq chime-max-consecutive-failures 0)
+        (cl-letf (((symbol-function 'display-warning)
+                   (lambda (_type _msg &rest _args) (setq warned t))))
+          (chime--maybe-warn-persistent-failures)
+          (should-not warned)))
+    (test-warn-failures-teardown)))
+
+(ert-deftest test-chime-warn-failures-zero-failures-no-warn ()
+  "Zero failures should never warn regardless of threshold."
+  (test-warn-failures-setup)
+  (unwind-protect
+      (let ((warned nil))
+        (setq chime--consecutive-async-failures 0)
+        (setq chime-max-consecutive-failures 5)
+        (cl-letf (((symbol-function 'display-warning)
+                   (lambda (_type _msg &rest _args) (setq warned t))))
+          (chime--maybe-warn-persistent-failures)
+          (should-not warned)))
+    (test-warn-failures-teardown)))
+
+(provide 'test-chime-warn-persistent-failures)
+;;; test-chime-warn-persistent-failures.el ends here