1 files changed, 275 insertions, 0 deletions
diff --git a/tests/test-agenda-query--render.el b/tests/test-agenda-query--render.el
new file mode 100644
index 00000000..48d28773
--- /dev/null
+++ b/tests/test-agenda-query--render.el
@@ -0,0 +1,275 @@
+;;; test-agenda-query--render.el --- Tests for the renderer profile -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Tests for `cj/agenda-render-json' and the row transform behind it.
+;;
+;; The renderer reads three keys — s and e as epoch MILLISECONDS, t as the
+;; title — and drops everything else before drawing.  Two things therefore have
+;; to hold, and both are asserted rather than assumed:
+;;
+;; 1. s and e really are milliseconds.  A seconds-for-milliseconds slip puts
+;;    every bar in 1970 and the surface renders empty, which looks exactly like
+;;    "Emacs isn't writing the file".
+;; 2. Every row has a drawable e.  The canonical profile reports null where the
+;;    source has no range, and null is not a width.
+;;
+;; Helpers carry a file-unique prefix: the editor hook loads every
+;; agenda-query test file into ONE process.
+
+;;; Code:
+
+(require 'ert)
+(require 'org)
+(require 'org-element)
+(require 'org-agenda)
+(require 'cl-lib)
+
+(add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
+(require 'agenda-query)
+;; Supplies `cj/org-todo-keywords', the vocabulary the batch writer sets and
+;; the editor's org config reads.
+(require 'user-constants)
+
+(defun test-aq-render--epoch (min hour day month year)
+  "Return the epoch for local MIN HOUR DAY MONTH YEAR."
+  (time-convert (encode-time (list 0 min hour day month year nil -1 nil))
+                'integer))
+
+(defmacro test-aq-render--with-agenda-file (text &rest body)
+  "Write TEXT to a temp agenda file and run BODY with `rows' bound.
+`rows' is the parsed render-profile output for all of 2026-07-31."
+  (declare (indent 1))
+  `(let* ((dir (make-temp-file "agenda-render-" t))
+          (file (expand-file-name "todo.org" dir)))
+     (unwind-protect
+         (progn
+           (with-temp-file file (insert ,text))
+           (let* ((org-agenda-files (list file))
+                  (rows (append (json-parse-string
+                                 (cj/agenda-render-json
+                                  (test-aq-render--epoch 0 0 31 7 2026)
+                                  (test-aq-render--epoch 59 23 31 7 2026))
+                                 :object-type 'alist)
+                                nil)))
+             ,@body))
+       (dolist (buffer (buffer-list))
+         (when (equal (buffer-file-name buffer) file) (kill-buffer buffer)))
+       (delete-directory dir t))))
+
+;;; Normal Cases
+
+(ert-deftest test-agenda-render-normal-emits-milliseconds ()
+  "Normal: s and e are epoch milliseconds, not seconds.
+
+The renderer works in milliseconds throughout.  Sending seconds puts every bar
+in January 1970, which draws as an empty surface — indistinguishable from the
+file never being written."
+  (test-aq-render--with-agenda-file
+      "* Standup\nSCHEDULED: <2026-07-31 Fri 09:00-09:30>\n"
+    (let ((row (car rows)))
+      (should (= (alist-get 's row)
+                 (* 1000 (test-aq-render--epoch 0 9 31 7 2026))))
+      (should (= (alist-get 'e row)
+                 (* 1000 (test-aq-render--epoch 30 9 31 7 2026))))
+      ;; Sanity on the magnitude: milliseconds since 1970 are 13 digits now.
+      (should (= 13 (length (number-to-string (alist-get 's row))))))))
+
+(ert-deftest test-agenda-render-normal-title-is-t ()
+  "Normal: the title is carried as t, the key the renderer reads."
+  (test-aq-render--with-agenda-file
+      "* TODO [#A] Standup with Nerses :work:\nSCHEDULED: <2026-07-31 Fri 09:00>\n"
+    (should (equal "Standup with Nerses" (alist-get 't (car rows))))))
+
+(ert-deftest test-agenda-render-normal-canonical-fields-survive ()
+  "Normal: the canonical fields ride along, since the consumer drops its own.
+One file serves both the renderer and anything reading the documented shape."
+  (test-aq-render--with-agenda-file
+      "* DONE Standup\nSCHEDULED: <2026-07-31 Fri 09:00-09:30>\n"
+    (let ((row (car rows)))
+      (should (equal "Standup" (alist-get 'title row)))
+      (should (eq t (alist-get 'done row)))
+      (should (equal "scheduled" (alist-get 'type row)))
+      ;; start stays SECONDS while s is milliseconds; the units never mix
+      ;; within a key.
+      (should (= (alist-get 'start row) (/ (alist-get 's row) 1000))))))
+
+;;; Boundary Cases
+
+(ert-deftest test-agenda-render-boundary-all-day-spans-its-day ()
+  "Boundary: an all-day entry gets a drawable e covering its whole day.
+Canonically its end is null, and null is not something a renderer can draw."
+  (test-aq-render--with-agenda-file
+      "* TODO Water plants\nSCHEDULED: <2026-07-31 Fri>\n"
+    (let ((row (car rows)))
+      (should (eq :null (alist-get 'end row)))
+      (should (= (alist-get 's row)
+                 (* 1000 (test-aq-render--epoch 0 0 31 7 2026))))
+      (should (= (alist-get 'e row)
+                 (* 1000 (1- (test-aq-render--epoch 0 0 1 8 2026))))))))
+
+(ert-deftest test-agenda-render-boundary-point-event-has-zero-width ()
+  "Boundary: a timed point event ends where it starts rather than at null.
+Zero width is a marker the renderer can decide how to draw; null is a crash or
+a silently dropped row."
+  (test-aq-render--with-agenda-file
+      "* Reminder\n<2026-07-31 Fri 14:00>\n"
+    (let ((row (car rows)))
+      (should (eq :null (alist-get 'end row)))
+      (should (= (alist-get 'e row) (alist-get 's row))))))
+
+(ert-deftest test-agenda-render-boundary-every-row-is-drawable ()
+  "Boundary: across a mixed day, every row has integer s and e with e >= s.
+This is the invariant the surface depends on, so it is asserted over the whole
+set rather than one row at a time."
+  (test-aq-render--with-agenda-file
+      (concat "* TODO All day\nSCHEDULED: <2026-07-31 Fri>\n"
+              "* Point\n<2026-07-31 Fri 14:00>\n"
+              "* Ranged\n<2026-07-31 Fri 15:00-16:30>\n"
+              "* TODO Deadline day\nDEADLINE: <2026-07-31 Fri 17:00>\n")
+    (should (= 4 (length rows)))
+    (dolist (row rows)
+      (should (integerp (alist-get 's row)))
+      (should (integerp (alist-get 'e row)))
+      (should (>= (alist-get 'e row) (alist-get 's row)))
+      (should (stringp (alist-get 't row))))))
+
+(ert-deftest test-agenda-render-boundary-empty-is-array ()
+  "Boundary: an empty day is an empty array, not null.
+The renderer parses the same shape whether or not anything is scheduled."
+  (let ((org-agenda-files nil))
+    (should (equal "[]" (cj/agenda-render-json 1785474000 1785477600)))))
+
+;;; ---------- the batch reader has to know the keyword vocabulary ----------
+
+(ert-deftest test-agenda-render-normal-custom-keyword-is-parsed ()
+  "Normal: a config keyword is recognised, so it leaves the title.
+
+The batch writer runs without the editor's init, so it has to set
+`org-todo-keywords' itself.  When it does not, org stops parsing the headline
+as a task at all: DOING and the priority cookie stay glued to the front of the
+title and the row reads as having no keyword.  That is a wrong answer that
+still parses as JSON, which is the worst kind."
+  (let ((org-todo-keywords cj/org-todo-keywords))
+    (test-aq-render--with-agenda-file
+        "* DOING [#A] Justin Johns advisor projects\nSCHEDULED: <2026-07-31 Fri 09:00>\n"
+      (let ((row (car rows)))
+        (should (equal "Justin Johns advisor projects" (alist-get 't row)))
+        (should (equal "DOING" (alist-get 'keyword row)))))))
+
+(ert-deftest test-agenda-render-boundary-unknown-keyword-stays-in-title ()
+  "Boundary: with stock keywords the same headline degrades visibly.
+
+Pinning the failure mode, not endorsing it.  This is what the surface showed
+before the batch writer learned the vocabulary, and it is why the test above
+exists."
+  (let ((org-todo-keywords '((sequence "TODO" "|" "DONE"))))
+    (test-aq-render--with-agenda-file
+        "* DOING [#A] Justin Johns advisor projects\nSCHEDULED: <2026-07-31 Fri 09:00>\n"
+      (should (string-prefix-p "DOING" (alist-get 't (car rows)))))))
+
+;;; ---------- the cache writer ----------
+
+(ert-deftest test-agenda-render-normal-cache-update-writes-today ()
+  "Normal: the cache writer covers three whole local days and creates its dir.
+
+Yesterday's midnight through tomorrow's day close.  A consumer drawing a
+rolling window centred on now needs both sides of midnight: with a single
+calendar day, the part of its span outside today has nothing to draw, which
+late in the evening is half the surface.
+
+This is the function that actually ships the feature, so it gets its own
+coverage rather than riding on the tests for the profile beneath it.  The
+window assertion is the point: a writer that quietly covered the last hour,
+or the next 24 from now, would still produce a plausible-looking file."
+  (let* ((dir (make-temp-file "agenda-cache-" t))
+         ;; A path two levels deep, so directory creation is exercised.
+         (cj/agenda-render-cache-file
+          (expand-file-name "settings/agenda.json" dir))
+         (org-agenda-files nil)
+         (windows '()))
+    (unwind-protect
+        (cl-letf (((symbol-function 'cj/agenda-render-json)
+                   (lambda (start end &optional out)
+                     (push (cons start end) windows)
+                     (when out (cj/--agenda-query-write-atomically out "[]"))
+                     "[]")))
+          (should (equal cj/agenda-render-cache-file
+                         (cj/agenda-render-cache-update)))
+          (should (file-exists-p cj/agenda-render-cache-file))
+          (let* ((window (car windows))
+                 (start (decode-time (car window)))
+                 (now (decode-time)))
+            ;; Opens at local midnight...
+            (should (= 0 (nth 2 start)))
+            (should (= 0 (nth 1 start)))
+            (should (= 0 (nth 0 start)))
+            ;; ...on yesterday, and closes at the end of tomorrow.
+            (should (= (car window)
+                       (cj/--agenda-query-epoch
+                        0 0 0 (1- (nth 3 now)) (nth 4 now) (nth 5 now))))
+            (should (= (cdr window)
+                       (cj/--agenda-query-day-close
+                        (1+ (nth 3 now)) (nth 4 now) (nth 5 now))))
+            ;; Three whole days, give or take an hour at a DST changeover.
+            (let ((hours (/ (- (cdr window) (car window)) 3600.0)))
+              (should (>= hours 70.9))
+              (should (<= hours 73.1)))))
+      (delete-directory dir t))))
+
+(ert-deftest test-agenda-render-boundary-cache-update-is-idempotent ()
+  "Boundary: writing twice leaves one file and no temp litter."
+  (let* ((dir (make-temp-file "agenda-cache-" t))
+         (cj/agenda-render-cache-file (expand-file-name "agenda.json" dir))
+         (org-agenda-files nil))
+    (unwind-protect
+        (progn
+          (cj/agenda-render-cache-update)
+          (cj/agenda-render-cache-update)
+          (should (equal '("agenda.json")
+                         (directory-files
+                          dir nil directory-files-no-dot-files-regexp))))
+      (delete-directory dir t))))
+
+;;; Error Cases
+
+(ert-deftest test-agenda-render-error-cache-update-unwritable-parent ()
+  "Error: an unwritable cache location signals rather than failing silently.
+A silent failure here looks identical to an empty agenda on the surface."
+  (let* ((dir (make-temp-file "agenda-cache-ro-" t))
+         (cj/agenda-render-cache-file
+          (expand-file-name "settings/agenda.json" dir))
+         (org-agenda-files nil))
+    (unwind-protect
+        (progn
+          (set-file-modes dir #o500)
+          (should-error (cj/agenda-render-cache-update)))
+      (set-file-modes dir #o700)
+      (delete-directory dir t))))
+
+(ert-deftest test-agenda-render-error-bounds-are-still-seconds ()
+  "Error: the render profile takes SECONDS in, even though it emits
+milliseconds.  The direction of conversion is one-way and the input guards
+still apply, so a caller passing milliseconds is told rather than answered."
+  (let ((org-agenda-files nil)
+        (ms 1785474000000))
+    (should-error (cj/agenda-render-json ms (+ ms 3600000)) :type 'user-error)))
+
+;;; Back to Normal Cases -- the profile's own writer
+
+(ert-deftest test-agenda-render-normal-writes-out-path ()
+  "Normal: with an out-path the render profile writes it atomically."
+  (let* ((dir (make-temp-file "agenda-render-out-" t))
+         (out (expand-file-name "agenda.json" dir))
+         (org-agenda-files nil))
+    (unwind-protect
+        (progn
+          (cj/agenda-render-json 1785474000 1785477600 out)
+          (should (file-exists-p out))
+          (with-temp-buffer
+            (insert-file-contents out)
+            (should (equal "[]" (buffer-string))))
+          (should (zerop (logand (file-modes out) #o111))))
+      (delete-directory dir t))))
+
+(provide 'test-agenda-query--render)
+;;; test-agenda-query--render.el ends here