test(config-utilities): cover with-timer, compile-buffer, summary, info commands

Four new test files extending the existing coverage of
cj/emacs-build--format-build-time. The interactive heavyweights
(cj/recompile-emacs-home, cj/delete-emacs-home-compiled-files,
cj/benchmark-this-method, cj/validate-org-agenda-timestamps) are out
of scope for this pass — each needs an internal/wrapper split first
before tests can exercise the logic without UI.

- with-timer macro: 4 tests asserting it returns the FORMS' value,
  evaluates the body exactly once, emits both announce and done
  messages, and returns the last form when given multiple.
- cj/compile-this-elisp-buffer: 6 tests dispatching across native-async,
  native-sync, and byte-compile fallbacks, plus the not-elisp /
  no-buffer-file-name error paths and the sync-native error catch.
- cj/emacs-build--summary-string: 5 tests asserting the shape of the
  multi-line report (Version, System, Build date, Capabilities section,
  yes/no flag rendering) without locking exact wording.
- info-commands smoke: 5 tests exercising cj/info-emacs-build,
  cj/info-loaded-packages, cj/info-loaded-features, cj/reload-init-file,
  and cj/org-alert-list-timers via boundary-mocked pop-to-buffer and
  load-file, asserting buffer creation, content shape, or echo-area
  message as appropriate.

20 new tests, all passing. Full suite green.

1 files changed, 54 insertions, 0 deletions

diff --git a/tests/test-config-utilities--with-timer.el b/tests/test-config-utilities--with-timer.el
new file mode 100644
index 00000000..74bbbc02
--- /dev/null
+++ b/tests/test-config-utilities--with-timer.el
@@ -0,0 +1,54 @@
+;;; test-config-utilities--with-timer.el --- Tests for the with-timer macro -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Tests for the `with-timer' macro from config-utilities.el. The macro
+;; runs FORMS, prints a timing message, and returns the value of FORMS.
+;; These tests verify that the macro preserves the result through the
+;; timing wrapper and that the announce/done messages fire.
+
+;;; Code:
+
+(require 'ert)
+(require 'cl-lib)
+
+(add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
+(require 'config-utilities)
+
+(ert-deftest test-config-utilities-with-timer-returns-forms-value ()
+  "Normal: with-timer returns the value of the wrapped FORMS."
+  (let ((inhibit-message t))
+    (should (= 42 (with-timer "compute"
+                    (+ 40 2))))))
+
+(ert-deftest test-config-utilities-with-timer-evaluates-forms-once ()
+  "Boundary: with-timer evaluates the body exactly once.
+Guards against the macro accidentally re-evaluating FORMS for the
+elapsed-time message or similar."
+  (let ((counter 0)
+        (inhibit-message t))
+    (with-timer "count"
+      (cl-incf counter))
+    (should (= 1 counter))))
+
+(ert-deftest test-config-utilities-with-timer-emits-announce-and-done-messages ()
+  "Boundary: with-timer emits both \"TITLE...\" and \"TITLE... done\" messages."
+  (let (messages)
+    (cl-letf (((symbol-function 'message)
+               (lambda (fmt &rest args) (push (apply #'format fmt args) messages))))
+      (with-timer "tag"
+        :ignored))
+    (let ((all (string-join (nreverse messages) "\n")))
+      (should (string-match-p "^tag\\.\\.\\.$" all))
+      (should (string-match-p "^tag\\.\\.\\. done (" all)))))
+
+(ert-deftest test-config-utilities-with-timer-multiple-forms-returns-last ()
+  "Boundary: with-timer with multiple forms returns the last form's value."
+  (let ((inhibit-message t))
+    (should (equal "third"
+                   (with-timer "multi"
+                     "first"
+                     "second"
+                     "third")))))
+
+(provide 'test-config-utilities--with-timer)
+;;; test-config-utilities--with-timer.el ends here