feat: undead-buffers: Add `cj/make-buffer-undead` function and tests

Introduce a new function `cj/make-buffer-undead` that appends a
buffer name to the `cj/undead-buffer-list`, preventing it from being
killed. This comes along with a suite of tests to check various
scenarios and edge cases for handling undead buffers.

Additionally, add tests for related functions:
`cj/kill-buffer-or-bury-alive`, `cj/kill-buffer-and-window`, and
others to ensure they correctly manage buffers, particularly with
undead-status considerations.

Refactor `undead-buffer-list` naming for consistency and clarity in
the module.

1 files changed, 112 insertions, 0 deletions

diff --git a/tests/test-undead-buffers-kill-buffer-and-window.el b/tests/test-undead-buffers-kill-buffer-and-window.el
new file mode 100644
index 00000000..b49969f6
--- /dev/null
+++ b/tests/test-undead-buffers-kill-buffer-and-window.el
@@ -0,0 +1,112 @@
+;;; test-undead-buffers-kill-buffer-and-window.el --- Tests for cj/kill-buffer-and-window -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Tests for the cj/kill-buffer-and-window function from undead-buffers.el
+
+;;; Code:
+
+(require 'ert)
+(require 'undead-buffers)
+(require 'testutil-general)
+
+;;; Setup and Teardown
+
+(defun test-kill-buffer-and-window-setup ()
+  "Setup for kill-buffer-and-window tests."
+  (cj/create-test-base-dir)
+  (delete-other-windows))
+
+(defun test-kill-buffer-and-window-teardown ()
+  "Teardown for kill-buffer-and-window tests."
+  (delete-other-windows)
+  (cj/delete-test-base-dir))
+
+;;; Normal Cases
+
+(ert-deftest test-kill-buffer-and-window-multiple-windows-should-delete-window-and-kill-buffer ()
+  "With multiple windows, should delete window and kill buffer."
+  (test-kill-buffer-and-window-setup)
+  (unwind-protect
+      (let ((buf (generate-new-buffer "*test-multi*")))
+        (unwind-protect
+            (progn
+              (split-window)
+              (switch-to-buffer buf)
+              (let ((win (selected-window)))
+                (cj/kill-buffer-and-window)
+                (should-not (window-live-p win))
+                (should-not (buffer-live-p buf))))
+          (when (buffer-live-p buf) (kill-buffer buf))))
+    (test-kill-buffer-and-window-teardown)))
+
+(ert-deftest test-kill-buffer-and-window-multiple-windows-undead-buffer-should-delete-window-and-bury ()
+  "With multiple windows, undead buffer should be buried and window deleted."
+  (test-kill-buffer-and-window-setup)
+  (unwind-protect
+      (let ((orig (copy-sequence cj/undead-buffer-list))
+            (buf (generate-new-buffer "*test-undead-multi*")))
+        (unwind-protect
+            (progn
+              (add-to-list 'cj/undead-buffer-list "*test-undead-multi*")
+              (split-window)
+              (switch-to-buffer buf)
+              (let ((win (selected-window)))
+                (cj/kill-buffer-and-window)
+                (should-not (window-live-p win))
+                (should (buffer-live-p buf))))
+          (setq cj/undead-buffer-list orig)
+          (when (buffer-live-p buf) (kill-buffer buf))))
+    (test-kill-buffer-and-window-teardown)))
+
+;;; Boundary Cases
+
+(ert-deftest test-kill-buffer-and-window-single-window-should-only-kill-buffer ()
+  "With single window, should only kill buffer, not delete window."
+  (test-kill-buffer-and-window-setup)
+  (unwind-protect
+      (let ((buf (generate-new-buffer "*test-single*")))
+        (unwind-protect
+            (progn
+              (switch-to-buffer buf)
+              (should (one-window-p))
+              (cj/kill-buffer-and-window)
+              (should (one-window-p))
+              (should-not (buffer-live-p buf)))
+          (when (buffer-live-p buf) (kill-buffer buf))))
+    (test-kill-buffer-and-window-teardown)))
+
+(ert-deftest test-kill-buffer-and-window-single-window-undead-buffer-should-only-bury ()
+  "With single window, undead buffer should only be buried."
+  (test-kill-buffer-and-window-setup)
+  (unwind-protect
+      (let ((orig (copy-sequence cj/undead-buffer-list))
+            (buf (generate-new-buffer "*test-undead-single*")))
+        (unwind-protect
+            (progn
+              (add-to-list 'cj/undead-buffer-list "*test-undead-single*")
+              (switch-to-buffer buf)
+              (should (one-window-p))
+              (cj/kill-buffer-and-window)
+              (should (one-window-p))
+              (should (buffer-live-p buf)))
+          (setq cj/undead-buffer-list orig)
+          (when (buffer-live-p buf) (kill-buffer buf))))
+    (test-kill-buffer-and-window-teardown)))
+
+(ert-deftest test-kill-buffer-and-window-two-windows-should-leave-one ()
+  "With two windows, should leave one window after deletion."
+  (test-kill-buffer-and-window-setup)
+  (unwind-protect
+      (let ((buf (generate-new-buffer "*test-two*")))
+        (unwind-protect
+            (progn
+              (split-window)
+              (set-window-buffer (selected-window) buf)
+              (should (= 2 (length (window-list))))
+              (cj/kill-buffer-and-window)
+              (should (= 1 (length (window-list)))))
+          (when (buffer-live-p buf) (kill-buffer buf))))
+    (test-kill-buffer-and-window-teardown)))
+
+(provide 'test-undead-buffers-kill-buffer-and-window)
+;;; test-undead-buffers-kill-buffer-and-window.el ends here