test: add gloss-display test suite (red phase)

Four test files covering the gloss-display public API and pure helpers.
All 23 tests fail at this commit because the implementation is still a
stub. Format-candidate gets full N/B/E coverage. Render-entry gets the
pure-helper treatment. Pick-definition mocks completing-read at the
boundary. Show-entry has a single smoke test.

1 files changed, 47 insertions, 0 deletions

diff --git a/tests/test-gloss-display--show-entry-smoke.el b/tests/test-gloss-display--show-entry-smoke.el
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+++ b/tests/test-gloss-display--show-entry-smoke.el
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+;;; test-gloss-display--show-entry-smoke.el --- Smoke test for gloss-display-show-entry -*- lexical-binding: t -*-
+
+;; SPDX-License-Identifier: GPL-3.0-or-later
+
+;;; Commentary:
+;; Smoke test for `gloss-display-show-entry'.  Exercises the side-buffer
+;; setup end to end: buffer creation, content rendering, mode activation,
+;; and the read-only invariant.  Per the design and project testing rules,
+;; framework primitives like `display-buffer' and major-mode mechanics are
+;; not re-tested.
+
+;;; Code:
+
+(require 'ert)
+(require 'gloss-display)
+
+(defmacro gloss-test--with-display-buffer-mocked (&rest body)
+  "Run BODY with `display-buffer' replaced by a no-op.
+Avoids opening a real side window during batch tests, while still letting
+`gloss-display-show-entry' populate and configure the entry buffer."
+  (declare (indent 0) (debug t))
+  `(cl-letf (((symbol-function 'display-buffer)
+              (lambda (buffer &rest _args) (get-buffer buffer))))
+     ,@body))
+
+(ert-deftest test-gloss-display-show-entry-creates-buffer-with-mode-and-content ()
+  "Smoke: show-entry creates a named buffer in `gloss-mode' with the entry."
+  (gloss-test--with-display-buffer-mocked
+    (unwind-protect
+        (let ((buf (gloss-display-show-entry
+                    "anaphora"
+                    "Reference to something earlier in the discourse.")))
+          (should (buffer-live-p buf))
+          (with-current-buffer buf
+            (should (derived-mode-p 'gloss-mode))
+            (should buffer-read-only)
+            (let ((contents (buffer-substring-no-properties
+                             (point-min) (point-max))))
+              (should (string-match-p "anaphora" contents))
+              (should (string-match-p "Reference to something earlier"
+                                      contents)))))
+      (when-let ((buf (get-buffer "*gloss: anaphora*")))
+        (let ((kill-buffer-query-functions nil))
+          (kill-buffer buf))))))
+
+(provide 'test-gloss-display--show-entry-smoke)
+;;; test-gloss-display--show-entry-smoke.el ends here