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+;;; test-wrap-up--bury-buffers.el --- Tests for cj/bury-buffers -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Characterization tests for cj/bury-buffers, which buries the noisy
+;; compile-and-shell buffers at the end of startup.
+;;
+;; Written to pin the buried set while a dead clause was removed.  The function
+;; tested `(derived-mode-p 'elisp-compile-mode)', and no such mode exists in
+;; Emacs -- the real one is `emacs-lisp-compilation-mode', which derives from
+;; `compilation-mode' and so was already matched by the clause above it.  The
+;; clause could never be true, and removing it must not change which buffers
+;; get buried.  These tests are what makes that claim checkable.
+;;
+;; Test organization:
+;; - Normal Cases: each buried mode is buried; byte-compilation output included
+;; - Boundary Cases: an ordinary buffer is left alone; an empty buffer list
+;; - Error Cases: a killed buffer in the list does not break the sweep
+;;
+;;; Code:
+
+(require 'ert)
+(add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
+(require 'wrap-up)
+
+;; Required explicitly so each test stands alone.  Without these the
+;; comint-mode test passed only because ERT runs tests in alphabetical order
+;; and an earlier test loaded `compile', which pulls in comint -- so renaming
+;; or running that test by itself made it fail with void-function comint-mode.
+(require 'comint)
+(require 'bytecomp)
+
+(defmacro test-wrap-up--with-mode-buffer (mode &rest body)
+  "Create a buffer in MODE, bind it to `buf', run BODY, then kill it."
+  (declare (indent 1))
+  `(let ((buf (generate-new-buffer "*test-bury*")))
+     (unwind-protect
+         (progn
+           (with-current-buffer buf (funcall ,mode))
+           ,@body)
+       (kill-buffer buf))))
+
+;;; Normal Cases
+
+(ert-deftest test-wrap-up-bury-buffers-buries-compilation ()
+  "Normal: a compilation-mode buffer is buried."
+  (test-wrap-up--with-mode-buffer #'compilation-mode
+    (switch-to-buffer buf)
+    (cj/bury-buffers)
+    (should-not (eq buf (car (buffer-list))))))
+
+(ert-deftest test-wrap-up-bury-buffers-buries-byte-compilation-output ()
+  "Normal: the real byte-compilation mode is buried.
+`emacs-lisp-compilation-mode' derives from `compilation-mode', which is
+why the never-matching elisp-compile-mode clause was redundant."
+  (should (eq 'compilation-mode
+              (get 'emacs-lisp-compilation-mode 'derived-mode-parent)))
+  (test-wrap-up--with-mode-buffer #'emacs-lisp-compilation-mode
+    (switch-to-buffer buf)
+    (cj/bury-buffers)
+    (should-not (eq buf (car (buffer-list))))))
+
+(ert-deftest test-wrap-up-bury-buffers-buries-comint ()
+  "Normal: a comint-mode buffer is buried."
+  (test-wrap-up--with-mode-buffer #'comint-mode
+    (switch-to-buffer buf)
+    (cj/bury-buffers)
+    (should-not (eq buf (car (buffer-list))))))
+
+;;; Boundary Cases
+
+(ert-deftest test-wrap-up-bury-buffers-leaves-ordinary-buffer ()
+  "Boundary: a fundamental-mode buffer is not buried."
+  (test-wrap-up--with-mode-buffer #'fundamental-mode
+    (switch-to-buffer buf)
+    (cj/bury-buffers)
+    (should (eq buf (car (buffer-list))))))
+
+(ert-deftest test-wrap-up-bury-buffers-leaves-text-buffer ()
+  "Boundary: an ordinary text-mode buffer is not buried."
+  (test-wrap-up--with-mode-buffer #'text-mode
+    (switch-to-buffer buf)
+    (cj/bury-buffers)
+    (should (eq buf (car (buffer-list))))))
+
+;;; Error Cases
+
+(ert-deftest test-wrap-up-bury-buffers-survives-dead-mode-name ()
+  "Error: the sweep completes even though elisp-compile-mode does not exist.
+The removed clause named a mode Emacs has never defined; this pins that
+the function still runs cleanly with no such mode anywhere."
+  (should-not (fboundp 'elisp-compile-mode))
+  (should-not (get 'elisp-compile-mode 'derived-mode-parent))
+  (cj/bury-buffers))
+
+(provide 'test-wrap-up--bury-buffers)
+;;; test-wrap-up--bury-buffers.el ends here