fix: cache timestamp reflects request time, not response time

float-time was captured in the outer let* before the async fetch.
The callback used this stale value, making cache entries appear
slightly older than they are. Move the float-time call into the
callback so the timestamp reflects when the data actually arrived.

2 files changed, 30 insertions, 3 deletions

diff --git a/tests/test-wttrin--get-cached-or-fetch.el b/tests/test-wttrin--get-cached-or-fetch.el
index fa6b9d0..75b4e8b 100644
--- a/tests/test-wttrin--get-cached-or-fetch.el
+++ b/tests/test-wttrin--get-cached-or-fetch.el
@@ -328,5 +328,33 @@ Proactive refresh keeps data fresh; on-demand reads always use cache."
           (should (equal callback-result test-wttrin--get-cached-or-fetch-new-weather))))
     (test-wttrin--get-cached-or-fetch-teardown)))
 
+(ert-deftest test-wttrin--get-cached-or-fetch-normal-timestamp-reflects-response-time ()
+  "Cache timestamp should reflect when the response arrived, not when
+the request was initiated.  A stale request-time timestamp would make
+the cached data appear older than it actually is."
+  (test-wttrin--get-cached-or-fetch-setup)
+  (unwind-protect
+      (let* ((location "Paris")
+             (cache-key (wttrin--make-cache-key location))
+             (response-time 5000.0))
+        (cl-letf (((symbol-function 'float-time)
+                   (lambda () response-time))
+                  ((symbol-function 'wttrin-fetch-raw-string)
+                   (lambda (_query callback)
+                     ;; Simulate time passing: response arrives later
+                     (setq response-time 5005.0)
+                     (funcall callback "fresh data")))
+                  ((symbol-function 'wttrin--cleanup-cache-if-needed)
+                   (lambda () nil)))
+          (let ((wttrin--force-refresh t))
+            (wttrin--get-cached-or-fetch
+             location
+             (lambda (_data) nil)))
+          ;; Timestamp should be 5005 (when callback ran), not 5000 (when request started)
+          (let ((cached (gethash cache-key wttrin--cache)))
+            (should cached)
+            (should (= (car cached) 5005.0)))))
+    (test-wttrin--get-cached-or-fetch-teardown)))
+
 (provide 'test-wttrin--get-cached-or-fetch)
 ;;; test-wttrin--get-cached-or-fetch.el ends here
diff --git a/wttrin.el b/wttrin.el
index d95f0c2..c2cb74d 100644
--- a/wttrin.el
+++ b/wttrin.el
@@ -444,8 +444,7 @@ regardless of age.  The background refresh timer keeps data fresh.
 CALLBACK is called with the weather data string when ready, or nil on error."
   (let* ((cache-key (wttrin--make-cache-key location))
          (cached (gethash cache-key wttrin--cache))
-         (data (cdr cached))
-         (now (float-time)))
+         (data (cdr cached)))
     (if (and cached (not wttrin--force-refresh))
         ;; Return cached data immediately regardless of age
         (funcall callback data)
@@ -456,7 +455,7 @@ CALLBACK is called with the weather data string when ready, or nil on error."
          (if fresh-data
              (progn
                (wttrin--cleanup-cache-if-needed)
-               (puthash cache-key (cons now fresh-data) wttrin--cache)
+               (puthash cache-key (cons (float-time) fresh-data) wttrin--cache)
                (funcall callback fresh-data))
            ;; On error, return stale cache if available
            (if cached