test: final-report message format and warning-branch zero-guard

6 ERT tests covering org-drill-final-report:

- Reviewed-count from done-entries appears in the message
- Pending-queue line lists per-queue counts (1 new, 2 young, etc.)
- 100% pass rate doesn't trigger the WARNING branch
- Below forgetting-index pass rate triggers the warning prompt
- Per-quality counts produce correct percentages (1/4 = 25%)
- Warning-branch with zero dormant+due survives (locks in the
  zero-divisor guard fix)

1 files changed, 162 insertions, 0 deletions

diff --git a/tests/test-org-drill-final-report.el b/tests/test-org-drill-final-report.el
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+++ b/tests/test-org-drill-final-report.el
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+;;; test-org-drill-final-report.el --- Tests for the final-report message  -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Tests for `org-drill-final-report' — the wrap-up summary shown at the
+;; end of every drill session.  The function builds a multiline message
+;; with reviewed-count, duration, per-quality recall percentages, and
+;; remaining-queue counts, then waits for a key.
+;;
+;; Tests mock `input-pending-p' / `read-char-exclusive' / `message' to
+;; bypass the wait loop and capture the formatted message.
+
+;;; Code:
+
+(require 'ert)
+(require 'cl-lib)
+(require 'org)
+(require 'org-drill)
+
+;;;; Helpers
+
+(defmacro with-fixed-now (&rest body)
+  `(cl-letf (((symbol-function 'current-time)
+              (lambda () (encode-time 0 0 12 5 5 2026))))
+     ,@body))
+
+(defmacro with-mocked-final-report-loop (&rest body)
+  "Run BODY with the final-report's wait loop short-circuited after one
+iteration so `message' actually fires.  Captures the last-shown prompt
+to `final-report-message'."
+  `(let ((final-report-message nil)
+         (loop-iters 0))
+     (cl-letf (((symbol-function 'input-pending-p)
+                (lambda ()
+                  (cl-incf loop-iters)
+                  (> loop-iters 1)))
+               ((symbol-function 'read-char-exclusive) (lambda (&optional _) ?x))
+               ((symbol-function 'sit-for) #'ignore)
+               ((symbol-function 'message)
+                (lambda (fmt &rest args)
+                  (setq final-report-message (apply #'format fmt args)))))
+       ,@body
+       final-report-message)))
+
+(defun make-marker-at-1 ()
+  (let ((m (make-marker))) (set-marker m 1) m))
+
+;;;; Format / content
+
+(ert-deftest test-final-report-includes-reviewed-count ()
+  "The N-items-reviewed count from done-entries appears."
+  (with-temp-buffer
+    (let ((session (org-drill-session)))
+      (oset session done-entries
+            (list (make-marker-at-1) (make-marker-at-1) (make-marker-at-1)))
+      (oset session start-time (float-time (encode-time 0 0 12 5 5 2026)))
+      (with-fixed-now
+        (let ((msg (with-mocked-final-report-loop
+                    (org-drill-final-report session))))
+          (should (string-match-p "3 items reviewed" msg)))))))
+
+(ert-deftest test-final-report-includes-pending-counts ()
+  "The remaining-queue line lists failed / overdue / new / young / old."
+  (with-temp-buffer
+    (let ((session (org-drill-session)))
+      (oset session new-entries (list (make-marker-at-1)))
+      (oset session young-mature-entries
+            (list (make-marker-at-1) (make-marker-at-1)))
+      (oset session start-time (float-time (encode-time 0 0 12 5 5 2026)))
+      (with-fixed-now
+        (let ((msg (with-mocked-final-report-loop
+                    (org-drill-final-report session))))
+          (should (string-match-p "1 new" msg))
+          (should (string-match-p "2 young" msg)))))))
+
+(ert-deftest test-final-report-100-percent-pass-skips-warning ()
+  "Perfect recall doesn't trigger the second `WARNING!' message."
+  (with-temp-buffer
+    (let ((session (org-drill-session))
+          (warning-shown nil))
+      (oset session qualities '(5 5 5 5))
+      (oset session start-time (float-time (encode-time 0 0 12 5 5 2026)))
+      (with-fixed-now
+        (cl-letf (((symbol-function 'input-pending-p) (lambda () t))
+                  ((symbol-function 'sit-for) #'ignore)
+                  ((symbol-function 'read-char-exclusive)
+                   (lambda (&optional msg)
+                     (when (and msg (string-match-p "WARNING" msg))
+                       (setq warning-shown t))
+                     ?x))
+                  ((symbol-function 'message) (lambda (&rest _))))
+          (org-drill-final-report session)
+          (should-not warning-shown))))))
+
+(ert-deftest test-final-report-low-pass-percent-shows-warning ()
+  "Pass rate below the forgetting-index complement triggers the warning prompt."
+  (with-temp-buffer
+    (let ((session (org-drill-session))
+          (warning-shown nil))
+      (oset session qualities '(0 0 0 0 0))   ; 0% pass
+      (oset session dormant-entry-count 5)
+      (oset session due-entry-count 5)
+      (oset session overdue-entry-count 2)
+      (oset session start-time (float-time (encode-time 0 0 12 5 5 2026)))
+      (with-fixed-now
+        (cl-letf (((symbol-function 'input-pending-p) (lambda () t))
+                  ((symbol-function 'sit-for) #'ignore)
+                  ((symbol-function 'read-char-exclusive)
+                   (lambda (&optional msg)
+                     (when (and msg (string-match-p "WARNING" msg))
+                       (setq warning-shown t))
+                     ?x))
+                  ((symbol-function 'message) (lambda (&rest _))))
+          (org-drill-final-report session)
+          (should warning-shown))))))
+
+(ert-deftest test-final-report-quality-counts-percentages ()
+  "Per-quality counts add up: 1 of 4 quality-5 ratings → 25%.
+Uses all passing ratings to avoid the warning branch's divide-by-zero
+on empty dormant/due counts."
+  (with-temp-buffer
+    (let ((session (org-drill-session)))
+      (oset session qualities '(5 4 4 4))   ; 100% pass, no warning fires
+      (oset session start-time (float-time (encode-time 0 0 12 5 5 2026)))
+      (with-fixed-now
+        (let ((msg (with-mocked-final-report-loop
+                    (org-drill-final-report session))))
+          ;; 1 of 4 = 25% Excellent
+          (should (string-match-p "Excellent (5):.*25%" msg))
+          ;; 3 of 4 = 75% Good
+          (should (string-match-p "Good (4):.*75%" msg)))))))
+
+(ert-deftest test-final-report-warning-branch-with-zero-dormant-and-due-survives ()
+  "The warning branch divides by (dormant + due), which is 0 in some
+edge cases (cram mode with zero items collected, or pure-failure
+sessions on empty queues).
+
+Pre-fix this hit `arith-error'.  The fix wraps the divisor with
+`(max 1 ...)' so the percentage gracefully reports 0%."
+  (with-temp-buffer
+    (let ((session (org-drill-session))
+          (warning-shown nil))
+      (oset session qualities '(0 0 0))            ; 0% pass
+      (oset session dormant-entry-count 0)         ; both zero — the bug shape
+      (oset session due-entry-count 0)
+      (oset session overdue-entry-count 0)
+      (oset session start-time (float-time (encode-time 0 0 12 5 5 2026)))
+      (with-fixed-now
+        (cl-letf (((symbol-function 'input-pending-p) (lambda () t))
+                  ((symbol-function 'sit-for) #'ignore)
+                  ((symbol-function 'read-char-exclusive)
+                   (lambda (&optional msg)
+                     (when (and msg (string-match-p "WARNING" msg))
+                       (setq warning-shown t))
+                     ?x))
+                  ((symbol-function 'message) (lambda (&rest _))))
+          ;; Pre-fix this errored out before reaching the assertion.
+          (org-drill-final-report session)
+          (should warning-shown))))))
+
+(provide 'test-org-drill-final-report)
+
+;;; test-org-drill-final-report.el ends here