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, 158 insertions, 0 deletions

diff --git a/tests/test-chime-get-tags.el b/tests/test-chime-get-tags.el
new file mode 100644
index 0000000..75cad00
--- /dev/null
+++ b/tests/test-chime-get-tags.el
@@ -0,0 +1,158 @@
+;;; test-chime-get-tags.el --- Tests for chime--get-tags and chime-done-keywords-predicate -*- 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 tag extraction and done-keyword predicate:
+;; - chime--get-tags: extracts org tags from a marker
+;; - chime-done-keywords-predicate: checks if heading has a done keyword
+
+;;; 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"))
+
+;;;; Tests for chime--get-tags
+
+;;; Normal Cases
+
+(ert-deftest test-chime-get-tags-single-tag ()
+  "Should extract a single tag from an org heading."
+  (with-temp-buffer
+    (org-mode)
+    (insert "* Task                                                        :work:\n")
+    (goto-char (point-min))
+    (let* ((marker (point-marker))
+           (tags (chime--get-tags marker)))
+      (should (member "work" tags)))))
+
+(ert-deftest test-chime-get-tags-multiple-tags ()
+  "Should extract multiple tags from an org heading."
+  (with-temp-buffer
+    (org-mode)
+    (insert "* Task                                                 :work:urgent:\n")
+    (goto-char (point-min))
+    (let* ((marker (point-marker))
+           (tags (chime--get-tags marker)))
+      (should (member "work" tags))
+      (should (member "urgent" tags)))))
+
+;;; Boundary Cases
+
+(ert-deftest test-chime-get-tags-no-tags ()
+  "Should return empty/nil list for heading with no tags."
+  (with-temp-buffer
+    (org-mode)
+    (insert "* Task without tags\n")
+    (goto-char (point-min))
+    (let* ((marker (point-marker))
+           (tags (chime--get-tags marker)))
+      ;; Should be empty (nil or empty list)
+      (should (null tags)))))
+
+(ert-deftest test-chime-get-tags-heading-with-todo-keyword ()
+  "Should extract tags correctly even with TODO keyword present."
+  (with-temp-buffer
+    (org-mode)
+    (insert "* TODO Task                                                 :meeting:\n")
+    (goto-char (point-min))
+    (let* ((marker (point-marker))
+           (tags (chime--get-tags marker)))
+      (should (member "meeting" tags)))))
+
+;;;; Tests for chime-done-keywords-predicate
+
+;;; Normal Cases
+
+(ert-deftest test-chime-done-predicate-done-keyword ()
+  "DONE heading should return truthy."
+  (with-temp-buffer
+    (org-mode)
+    (insert "* DONE Completed task\n")
+    (goto-char (point-min))
+    (let ((marker (point-marker)))
+      (should (chime-done-keywords-predicate marker)))))
+
+(ert-deftest test-chime-done-predicate-todo-keyword ()
+  "TODO heading should return nil."
+  (with-temp-buffer
+    (org-mode)
+    (insert "* TODO Active task\n")
+    (goto-char (point-min))
+    (let ((marker (point-marker)))
+      (should-not (chime-done-keywords-predicate marker)))))
+
+(ert-deftest test-chime-done-predicate-no-keyword ()
+  "Heading without any TODO keyword should return nil."
+  (with-temp-buffer
+    (org-mode)
+    (insert "* Plain heading\n")
+    (goto-char (point-min))
+    (let ((marker (point-marker)))
+      (should-not (chime-done-keywords-predicate marker)))))
+
+;;; Boundary Cases
+
+(ert-deftest test-chime-done-predicate-custom-done-keywords ()
+  "Custom done keywords (org-done-keywords) should be recognized."
+  (with-temp-buffer
+    (org-mode)
+    ;; CANCELLED is a standard done keyword in many org configs,
+    ;; but org-done-keywords defaults to just ("DONE").
+    ;; Test with the default DONE keyword.
+    (insert "* DONE Task\n")
+    (goto-char (point-min))
+    (let ((marker (point-marker)))
+      (should (member (nth 2 (org-heading-components)) org-done-keywords)))))
+
+(ert-deftest test-chime-done-predicate-heading-with-priority ()
+  "DONE heading with priority should still be detected."
+  (with-temp-buffer
+    (org-mode)
+    (insert "* DONE [#A] High priority done task\n")
+    (goto-char (point-min))
+    (let ((marker (point-marker)))
+      (should (chime-done-keywords-predicate marker)))))
+
+(ert-deftest test-chime-done-predicate-heading-with-tags ()
+  "DONE heading with tags should still be detected."
+  (with-temp-buffer
+    (org-mode)
+    (insert "* DONE Tagged task                                          :work:\n")
+    (goto-char (point-min))
+    (let ((marker (point-marker)))
+      (should (chime-done-keywords-predicate marker)))))
+
+(provide 'test-chime-get-tags)
+;;; test-chime-get-tags.el ends here