From 0b93863689038a385fd320440ac0a413ce81c4e1 Mon Sep 17 00:00:00 2001 From: Craig Jennings Date: Fri, 31 Jul 2026 12:39:27 -0500 Subject: fix(prompts): make destructive confirms one keystroke I had to kill an Emacs session today over a prompt I could not answer. A second agent session held the selected window while "Overwrite hiroshi.m3u? (yes or no)" waited in another frame, so my keystrokes went to a terminal and the minibuffer stayed empty. Losing unsaved buffers is a far worse outcome than a mis-keyed confirm. So cj/confirm-strong becomes cj/confirm-destructive, and instead of binding use-short-answers to nil for a typed "yes" it reads a single y or n. Two things I kept: - No default. Only y and n answer, so a stray RET or space re-prompts rather than confirming a shutdown. - Pending input is discarded before the read. Without that the change would have been a bad trade: read-char-choice reads the input queue, so a key typed before the prompt painted would confirm instantly, where the old typed-"yes" absorbed it harmlessly. Worth being honest about what this does not fix. One keystroke does not make a prompt reachable when focus is elsewhere, and C-g is still the escape. It lowers the cost of the situation rather than preventing it. Six call sites: shutdown and reboot, shred, playlist overwrite and delete, and the two file overwrites. --- tests/test-system-commands-resolve-and-run.el | 45 ++++++++++++++++++++++----- 1 file changed, 38 insertions(+), 7 deletions(-) (limited to 'tests/test-system-commands-resolve-and-run.el') diff --git a/tests/test-system-commands-resolve-and-run.el b/tests/test-system-commands-resolve-and-run.el index 7e5146b1..3dae8cda 100644 --- a/tests/test-system-commands-resolve-and-run.el +++ b/tests/test-system-commands-resolve-and-run.el @@ -85,26 +85,34 @@ (put 'test-sc-confirm-cmd 'cj/system-confirm nil))) (ert-deftest test-system-cmd-strong-confirm-decline-aborts () - "Boundary: a strong-confirm var uses yes-or-no-p; declining aborts and -does not run the command." + "Boundary: a strong-confirm var asks a single y/n; declining aborts and +does not run the command. + +The strong path used to demand a typed \"yes\", and this test used to assert +that by erroring if `read-char-choice' was called at all. It now asserts the +opposite, because a long-form prompt is only as safe as it is answerable: on +2026-07-31 one became unanswerable when a second agent session held the +selected window, and the Emacs session had to be killed with buffers unsaved. +What survives the change is the part that mattered -- the prompt still has no +default, so RET and space re-prompt rather than confirming a shutdown." (defvar test-sc-strong-cmd "test-strong-cmd") (put 'test-sc-strong-cmd 'cj/system-confirm 'strong) (unwind-protect - (cl-letf (((symbol-function 'yes-or-no-p) (lambda (&rest _) nil)) - ((symbol-function 'read-char-choice) - (lambda (&rest _) (error "strong confirm must not use read-char-choice"))) + (cl-letf (((symbol-function 'read-char-choice) (lambda (&rest _) ?n)) + ((symbol-function 'yes-or-no-p) + (lambda (&rest _) (error "strong confirm must not demand a typed yes"))) ((symbol-function 'start-process-shell-command) (lambda (&rest _) (error "shouldn't run")))) (should-error (cj/system-cmd 'test-sc-strong-cmd) :type 'user-error)) (put 'test-sc-strong-cmd 'cj/system-confirm nil))) (ert-deftest test-system-cmd-strong-confirm-accept-runs () - "Normal: a strong-confirm var runs the command when yes-or-no-p returns t." + "Normal: a strong-confirm var runs the command on a single y." (defvar test-sc-strong-cmd-2 "echo strong") (put 'test-sc-strong-cmd-2 'cj/system-confirm 'strong) (let (cmd-line) (unwind-protect - (cl-letf (((symbol-function 'yes-or-no-p) (lambda (&rest _) t)) + (cl-letf (((symbol-function 'read-char-choice) (lambda (&rest _) ?y)) ((symbol-function 'start-process-shell-command) (lambda (_name _buf c) (setq cmd-line c) 'fake-proc)) ((symbol-function 'set-process-query-on-exit-flag) #'ignore) @@ -114,6 +122,29 @@ does not run the command." (put 'test-sc-strong-cmd-2 'cj/system-confirm nil)) (should (string-match-p "echo strong" cmd-line)))) +(ert-deftest test-system-cmd-strong-confirm-rejects-stray-keys () + "Boundary: the strong prompt offers only y and n, so a stray RET or space +cannot confirm an irreversible command. + +This is the protection the typed-\"yes\" form existed for, kept while the +answer became a single keystroke. Asserted on the accepted-character set +handed to `read-char-choice' rather than on the prompt text, because the set +is what actually decides." + (defvar test-sc-strong-cmd-3 "echo strong") + (put 'test-sc-strong-cmd-3 'cj/system-confirm 'strong) + (let (chars) + (unwind-protect + (cl-letf (((symbol-function 'read-char-choice) + (lambda (_prompt cs &rest _) (setq chars cs) ?n)) + ((symbol-function 'start-process-shell-command) + (lambda (&rest _) (error "shouldn't run")))) + (should-error (cj/system-cmd 'test-sc-strong-cmd-3) :type 'user-error)) + (put 'test-sc-strong-cmd-3 'cj/system-confirm nil)) + (should (equal (sort (copy-sequence chars) #'<) '(?N ?Y ?n ?y))) + (should-not (memq ?\r chars)) + (should-not (memq ?\n chars)) + (should-not (memq ?\s chars)))) + ;;; cj/system-cmd--emacs-service-available-p (ert-deftest test-system-cmd-service-available-true-on-zero-exit () -- cgit v1.2.3