From 9c0dbf985cdc3360b47adc24f50964f8cf04b2cc Mon Sep 17 00:00:00 2001
From: Craig Jennings <c@cjennings.net>
Date: Sun, 24 May 2026 15:28:25 -0500
Subject: test: cover sort and render ordering boundary cases

Added ERT tests for the deterministic-ordering guarantees: title sort folds nil and empty titles to the empty key (ordered first ascending); a nil (none) priority sorts last ascending and first descending; equal keys keep input order ascending and reverse it descending (Emacs sort is stable, then nreverse); and the render boundary sorts by priority after normalization even when a node omits the field. 384 tests green.
---
 tests/test-pearl-saved.el | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/tests/test-pearl-saved.el b/tests/test-pearl-saved.el
index 63a3f8c..88bf468 100644
--- a/tests/test-pearl-saved.el
+++ b/tests/test-pearl-saved.el
@@ -108,5 +108,51 @@
       (should (equal '("apple" "banana")
                      (mapcar (lambda (i) (plist-get i :title)) written))))))
 
+;;; sort boundary cases
+
+(ert-deftest test-pearl-sort-issues-title-nil-and-empty ()
+  "Title sort treats nil and empty titles as empty strings, ordered first ascending."
+  (let ((out (pearl--sort-issues
+              '((:title "banana") (:title nil) (:title "apple") (:title ""))
+              'title 'asc)))
+    ;; both empties sort before the named titles; their relative order is the
+    ;; stable input order (nil came before the empty string)
+    (should (equal '(nil "" "apple" "banana")
+                   (mapcar (lambda (i) (plist-get i :title)) out)))))
+
+(ert-deftest test-pearl-sort-issues-priority-nil-is-last-asc ()
+  "A nil (none) priority sorts last ascending and first descending."
+  (let ((issues '((:title "p2" :priority 2) (:title "none" :priority nil) (:title "p1" :priority 1))))
+    (should (equal '("p1" "p2" "none")
+                   (mapcar (lambda (i) (plist-get i :title))
+                           (pearl--sort-issues issues 'priority 'asc))))
+    (should (equal '("none" "p2" "p1")
+                   (mapcar (lambda (i) (plist-get i :title))
+                           (pearl--sort-issues issues 'priority 'desc))))))
+
+(ert-deftest test-pearl-sort-issues-equal-keys-deterministic ()
+  "Equal keys keep input order ascending and reverse it descending (stable sort + nreverse)."
+  (let ((issues '((:title "a" :priority 2) (:title "b" :priority 2) (:title "c" :priority 2))))
+    (should (equal '("a" "b" "c")
+                   (mapcar (lambda (i) (plist-get i :title))
+                           (pearl--sort-issues issues 'priority 'asc))))
+    (should (equal '("c" "b" "a")
+                   (mapcar (lambda (i) (plist-get i :title))
+                           (pearl--sort-issues issues 'priority 'desc))))))
+
+(ert-deftest test-pearl-render-query-result-sorts-with-missing-priority ()
+  "Render sorts by priority after normalization even when a node lacks the field."
+  (let ((written nil)
+        (source '(:type filter :name "By priority" :filter nil :sort priority :order asc)))
+    (cl-letf (((symbol-function 'pearl--normalize-issue) #'identity)
+              ((symbol-function 'pearl--update-org-from-issues)
+               (lambda (issues &optional _s _t) (setq written issues))))
+      (pearl--render-query-result
+       (pearl--make-query-result
+        'ok :issues '((:title "hi" :priority 1) (:title "none") (:title "lo" :priority 3)))
+       source)
+      (should (equal '("hi" "lo" "none")
+                     (mapcar (lambda (i) (plist-get i :title)) written))))))
+
 (provide 'test-pearl-saved)
 ;;; test-pearl-saved.el ends here
-- 
cgit v1.2.3