From fdc63ea6675709d6ca42362b1be1918f8bf24478 Mon Sep 17 00:00:00 2001
From: Craig Jennings <c@cjennings.net>
Date: Wed, 1 Apr 2026 08:13:33 -0500
Subject: feat(music): add test coverage for 7 functions, refactor with
 extracted helpers

Add 47 new unit tests across 7 test files covering playlist-modified-p,
assert-valid-playlist-file, playlist-tracks, create-radio-station,
ensure-playlist-buffer, after-playlist-clear, and header-text.

Extract three helpers to reduce duplication: assert-m3u-files-exist (dedupes
2 identical guards), sync-playlist-file (dedupes 3 state-sync patterns),
and select-m3u-file (reusable M3U selection with cancel). Simplify
append-track-to-playlist nesting from 6 to 4 levels. Delete unused
cj/music-keymap-prefix variable.
---
 tests/test-music-config--after-playlist-clear.el | 116 +++++++++++++++++++++++
 1 file changed, 116 insertions(+)
 create mode 100644 tests/test-music-config--after-playlist-clear.el

(limited to 'tests/test-music-config--after-playlist-clear.el')

diff --git a/tests/test-music-config--after-playlist-clear.el b/tests/test-music-config--after-playlist-clear.el
new file mode 100644
index 00000000..c23e2b5b
--- /dev/null
+++ b/tests/test-music-config--after-playlist-clear.el
@@ -0,0 +1,116 @@
+;;; test-music-config--after-playlist-clear.el --- Tests for playlist clear advice -*- coding: utf-8; lexical-binding: t; -*-
+;;
+;; Author: Craig Jennings <c@cjennings.net>
+;;
+;;; Commentary:
+;; Unit tests for cj/music--after-playlist-clear function.
+;; Tests the advice function that resets cj/music-playlist-file
+;; when the EMMS playlist is cleared.
+;;
+;; Test organization:
+;; - Normal Cases: Clears file variable, noop when no buffer
+;; - Boundary Cases: Already nil stays nil, idempotent on multiple calls
+;; - Error Cases: Killed buffer doesn't crash
+;;
+;;; Code:
+
+(require 'ert)
+
+;; Stub missing dependencies before loading music-config
+(defvar-keymap cj/custom-keymap
+  :doc "Stub keymap for testing")
+
+;; Add EMMS elpa directory to load path for batch testing
+(let ((emms-dir (car (file-expand-wildcards
+                      (expand-file-name "elpa/emms-*" user-emacs-directory)))))
+  (when emms-dir
+    (add-to-list 'load-path emms-dir)))
+
+(require 'emms)
+(require 'emms-playlist-mode)
+(require 'music-config)
+
+;;; Test helpers
+
+(defun test-after-clear--setup ()
+  "Create playlist buffer with a playlist file set."
+  (let ((buf (get-buffer-create cj/music-playlist-buffer-name)))
+    (with-current-buffer buf
+      (emms-playlist-mode)
+      (setq emms-playlist-buffer-p t))
+    (setq emms-playlist-buffer buf)
+    buf))
+
+(defun test-after-clear--teardown ()
+  "Clean up test playlist buffer."
+  (when-let ((buf (get-buffer cj/music-playlist-buffer-name)))
+    (with-current-buffer buf
+      (setq cj/music-playlist-file nil))
+    (kill-buffer buf)))
+
+;;; Normal Cases
+
+(ert-deftest test-music-config--after-playlist-clear-normal-clears-file-variable ()
+  "Calling after-playlist-clear sets cj/music-playlist-file to nil."
+  (unwind-protect
+      (progn
+        (test-after-clear--setup)
+        (with-current-buffer cj/music-playlist-buffer-name
+          (setq cj/music-playlist-file "/path/to/playlist.m3u"))
+        (cj/music--after-playlist-clear)
+        (with-current-buffer cj/music-playlist-buffer-name
+          (should-not cj/music-playlist-file)))
+    (test-after-clear--teardown)))
+
+(ert-deftest test-music-config--after-playlist-clear-normal-noop-when-no-buffer ()
+  "Does nothing when playlist buffer doesn't exist."
+  (unwind-protect
+      (progn
+        ;; Ensure no buffer exists
+        (when-let ((buf (get-buffer cj/music-playlist-buffer-name)))
+          (kill-buffer buf))
+        ;; Should not error
+        (cj/music--after-playlist-clear))
+    (test-after-clear--teardown)))
+
+;;; Boundary Cases
+
+(ert-deftest test-music-config--after-playlist-clear-boundary-already-nil-stays-nil ()
+  "Already-nil playlist file remains nil after clear."
+  (unwind-protect
+      (progn
+        (test-after-clear--setup)
+        (with-current-buffer cj/music-playlist-buffer-name
+          (setq cj/music-playlist-file nil))
+        (cj/music--after-playlist-clear)
+        (with-current-buffer cj/music-playlist-buffer-name
+          (should-not cj/music-playlist-file)))
+    (test-after-clear--teardown)))
+
+(ert-deftest test-music-config--after-playlist-clear-boundary-multiple-calls-idempotent ()
+  "Multiple calls produce same result as single call."
+  (unwind-protect
+      (progn
+        (test-after-clear--setup)
+        (with-current-buffer cj/music-playlist-buffer-name
+          (setq cj/music-playlist-file "/path/to/playlist.m3u"))
+        (cj/music--after-playlist-clear)
+        (cj/music--after-playlist-clear)
+        (cj/music--after-playlist-clear)
+        (with-current-buffer cj/music-playlist-buffer-name
+          (should-not cj/music-playlist-file)))
+    (test-after-clear--teardown)))
+
+;;; Error Cases
+
+(ert-deftest test-music-config--after-playlist-clear-error-killed-buffer-no-crash ()
+  "Killed buffer doesn't cause an error."
+  (let ((buf (test-after-clear--setup)))
+    (kill-buffer buf)
+    ;; Should not error when buffer is gone
+    (should-not (condition-case err
+                    (progn (cj/music--after-playlist-clear) nil)
+                  (error err)))))
+
+(provide 'test-music-config--after-playlist-clear)
+;;; test-music-config--after-playlist-clear.el ends here
-- 
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