fix: don't auto-fit the loading placeholder to a huge font

With auto-fit on, the one-line "Loading..." placeholder was sized to fill the
window height (capped huge), and a reused buffer kept the previous weather's
auto-fitted font while loading. Auto-fit now runs only once real weather has
rendered, and the placeholder resets to the base font.

1 files changed, 39 insertions, 0 deletions

diff --git a/tests/test-wttrin--update-layout.el b/tests/test-wttrin--update-layout.el
new file mode 100644
index 0000000..b8df665
--- /dev/null
+++ b/tests/test-wttrin--update-layout.el
@@ -0,0 +1,39 @@
+;;; test-wttrin--update-layout.el --- Auto-fit gating -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2024-2026 Craig Jennings
+
+;;; Commentary:
+;; Auto-fit must not size the transient "Loading..." placeholder to fill the
+;; window; it runs only once real weather has rendered.
+
+;;; Code:
+
+(require 'ert)
+(require 'cl-lib)
+(require 'wttrin)
+(require 'testutil-wttrin)
+
+(ert-deftest test-wttrin--update-layout-error-skips-fit-on-placeholder ()
+  "Error: with auto-fit on, the loading placeholder (weather not rendered) is
+not auto-fitted; the fit runs only after weather renders."
+  (let ((buf (get-buffer-create "*wttrin-layout-test*"))
+        (fit-calls 0))
+    (unwind-protect
+        (save-window-excursion
+          (cl-letf (((symbol-function 'wttrin--apply-fit-font)
+                     (lambda (&rest _) (setq fit-calls (1+ fit-calls))))
+                    ((symbol-function 'wttrin--center-buffer) #'ignore))
+            (with-current-buffer buf (insert "Loading..."))
+            (set-window-buffer (selected-window) buf)
+            (with-current-buffer buf
+              (let ((wttrin-auto-fit-font t))
+                (setq-local wttrin--weather-rendered nil)
+                (wttrin--update-layout)
+                (should (= 0 fit-calls))
+                (setq-local wttrin--weather-rendered t)
+                (wttrin--update-layout)
+                (should (= 1 fit-calls))))))
+      (kill-buffer buf))))
+
+(provide 'test-wttrin--update-layout)
+;;; test-wttrin--update-layout.el ends here