fix(markdown): restore the live preview (rename, guard, dead setq)

F2 ran markdown-mode's own markdown-preview instead of the custom one, so the impatient-mode strapdown preview was dead. I renamed the custom command to cj/markdown-preview and rebound F2 so markdown-mode no longer shadows it. The server guard now uses httpd-running-p (httpd-process isn't a variable), and a dead (setq imp-set-user-filter 'markdown-html) that named neither a real variable nor a real filter is gone.

3 files changed, 23 insertions, 7 deletions

diff --git a/modules/markdown-config.el b/modules/markdown-config.el
index 4faa4474..16935425 100644
--- a/modules/markdown-config.el
+++ b/modules/markdown-config.el
@@ -21,7 +21,7 @@
 		 ("\\.md\\'"       . markdown-mode)
          ("\\.markdown\\'" . markdown-mode))
   :bind (:map markdown-mode-map
-			  ("<f2>" . markdown-preview)) ;; use same key as compile for consistency
+			  ("<f2>" . cj/markdown-preview)) ;; use same key as compile for consistency
   :init (setq markdown-command "multimarkdown"))
 
 ;; Register markdown as a known org-src-block language so `org-lint'
@@ -36,9 +36,7 @@
 ;; allows for live previews of your html
 ;; see: https://github.com/skeeto/impatient-mode
 (use-package impatient-mode
-  :defer t
-  :config
-  (setq imp-set-user-filter 'markdown-html))
+  :defer t)
 
 ;;;; --------------------- WIP: Markdown-Preview ---------------------
 
@@ -51,14 +49,14 @@ Idempotent: re-running while the server is already up is a no-op."
   (message "markdown preview server running on http://localhost:8080/imp"))
 
 ;; the filter to apply to markdown before impatient-mode pushes it to the server
-(defun markdown-preview ()
+(defun cj/markdown-preview ()
   "Open the current buffer as a live HTML preview at http://localhost:8080/imp.
 The simple-httpd listener must already be running -- see
 `cj/markdown-preview-server-start'.  Starting a network listener as a
 side effect of opening a preview is surprising, so the server start
 lives in a separate command."
   (interactive)
-  (unless (and (boundp 'httpd-process) httpd-process)
+  (unless (httpd-running-p)
     (user-error "markdown preview server not running; run `M-x cj/markdown-preview-server-start' first"))
   (impatient-mode 1)
   (setq imp-user-filter #'cj/markdown-html)
diff --git a/tests/test-markdown-config.el b/tests/test-markdown-config.el
index 45e1a601..edb20d35 100644
--- a/tests/test-markdown-config.el
+++ b/tests/test-markdown-config.el
@@ -9,6 +9,7 @@
 ;;; Code:
 
 (require 'ert)
+(require 'cl-lib)
 
 (add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
 
@@ -50,5 +51,14 @@
           (should (string-match-p "<xmp" (buffer-string))))
       (kill-buffer src))))
 
+;;; cj/markdown-preview (guard: refuse when the httpd listener is down)
+
+(ert-deftest test-markdown-preview-errors-when-server-down ()
+  "Error: `cj/markdown-preview' signals a user-error when the simple-httpd
+listener is not running, rather than opening a preview against a dead server.
+Also pins the rename off the bare `markdown-preview' that markdown-mode shadows."
+  (cl-letf (((symbol-function 'httpd-running-p) (lambda () nil)))
+    (should-error (cj/markdown-preview) :type 'user-error)))
+
 (provide 'test-markdown-config)
 ;;; test-markdown-config.el ends here
diff --git a/todo.org b/todo.org
index 2a12cada..6cd4cadb 100644
--- a/todo.org
+++ b/todo.org
@@ -857,8 +857,10 @@ From the 2026-06 config audit. =modules/auth-config.el:88= — bare =(call-proce
 ** TODO [#B] system-defaults: top-level server-start unguarded in batch :bug:quick:solo:
 =modules/system-defaults.el:140= — raw module load under =--batch= (make validate-modules on a machine with no daemon socket) starts a server from a batch process; the suite only passes because the testutil stubs it. Wrap in =(unless noninteractive ...)= — the repo's established guard for this defect class; same guard stops the =custom-file= =make-temp-file= at line 104 littering temp files per batch load. From the 2026-06 config audit.
 
-** TODO [#B] markdown live preview clobbered by markdown-mode :bug:quick:solo:
+** DONE [#B] markdown live preview clobbered by markdown-mode :bug:quick:solo:
+CLOSED: [2026-06-13 Sat]
 =modules/markdown-config.el:54= defines bare =markdown-preview=, which markdown-mode redefines the moment the first .md loads — the impatient-mode live preview is dead and F2 silently runs the package command (agent verified in the live daemon). Also =:61= guards on =(boundp 'httpd-process)=, a variable that doesn't exist in simple-httpd — use =(httpd-running-p)=. And the =:config= =(setq imp-set-user-filter 'markdown-html)= at line 41 is doubly dead (function-not-variable, symbol names nothing) — delete. Rename to =cj/markdown-preview=, rebind F2. From the 2026-06 config audit.
+Fixed 2026-06-13: renamed the defun to =cj/markdown-preview= and rebound =<f2>=; guard is now =(httpd-running-p)=; deleted the dead =(setq imp-set-user-filter 'markdown-html)= (impatient-mode use-package is now =:defer t= only). Added a guard test (server-down → user-error); 4/4 green; live daemon confirms =cj/markdown-preview= defined and guarding. Browser-render check is a VERIFY.
 
 ** TODO [#B] agenda sources: roam Projects missing, no existence filtering :bug:solo:
 From the 2026-06 config audit, =modules/org-agenda-config.el=:
@@ -4340,6 +4342,12 @@ From the 2026-06-11 messenger-unification brainstorm. Google Voice has no offici
 
 ** TODO Manual testing and validation
 Exercised once the phases above land.
+*** VERIFY markdown live preview renders in the browser
+What we're verifying: F2 in a markdown buffer runs the custom cj/markdown-preview (not markdown-mode's own command) and the impatient-mode strapdown preview actually renders. Fixed in modules/markdown-config.el, reloaded into the daemon.
+- Open a .md file with some markdown content
+- M-x cj/markdown-preview-server-start (starts simple-httpd on :8080)
+- Press F2 in the markdown buffer
+Expected: a browser opens http://localhost:8080/imp showing the rendered markdown, and edits to the buffer update the preview live. Pressing F2 before starting the server gives a user-error telling you to start it.
 *** VERIFY orderless matching works inside a vertico session
 What we're verifying: vertico-prescient no longer overrides completion-styles, so orderless's space-separated, out-of-order matching is live in the minibuffer (prescient still sorts). Fixed in modules/selection-framework.el, applied live in the daemon.
 - Run a command with a vertico minibuffer (e.g. M-x, or C-x b)