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, 85 insertions, 0 deletions

diff --git a/tests/test-gloss-display--pick-definition.el b/tests/test-gloss-display--pick-definition.el
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+++ b/tests/test-gloss-display--pick-definition.el
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+;;; test-gloss-display--pick-definition.el --- Tests for gloss-display-pick-definition -*- lexical-binding: t -*-
+
+;; SPDX-License-Identifier: GPL-3.0-or-later
+
+;;; Commentary:
+;; Tests for `gloss-display-pick-definition' covering Normal/Boundary/Error
+;; cases.  The picker mocks `completing-read' at the boundary; the function
+;; under test is responsible for building the alist of formatted-string ->
+;; plist and mapping the user's choice back to the chosen plist.
+
+;;; Code:
+
+(require 'ert)
+(require 'cl-lib)
+(require 'gloss-display)
+
+(defmacro gloss-test--with-completing-read (return-value &rest body)
+  "Run BODY with `completing-read' mocked to return RETURN-VALUE.
+If RETURN-VALUE is the symbol `quit', simulate the user pressing C-g
+by signalling `quit' inside the mock."
+  (declare (indent 1) (debug t))
+  `(cl-letf (((symbol-function 'completing-read)
+              (lambda (&rest _args)
+                ,(if (eq return-value 'quit)
+                     '(signal 'quit nil)
+                   return-value))))
+     ,@body))
+
+(ert-deftest test-gloss-display-pick-definition-normal-pick-first-of-three ()
+  "Normal: choosing the first row returns the first definition plist."
+  (let* ((def1 '(:source wiktionary :text "First sense."))
+         (def2 '(:source wiktionary :text "Second sense."))
+         (def3 '(:source wiktionary :text "Third sense."))
+         (defs (list def1 def2 def3))
+         (chosen-row (gloss-display--format-candidate def1)))
+    (gloss-test--with-completing-read chosen-row
+      (should (equal (gloss-display-pick-definition "term" defs) def1)))))
+
+(ert-deftest test-gloss-display-pick-definition-normal-pick-middle-of-three ()
+  "Normal: choosing the middle row returns the middle definition plist."
+  (let* ((def1 '(:source wiktionary :text "First sense."))
+         (def2 '(:source wiktionary :text "Second sense."))
+         (def3 '(:source wiktionary :text "Third sense."))
+         (defs (list def1 def2 def3))
+         (chosen-row (gloss-display--format-candidate def2)))
+    (gloss-test--with-completing-read chosen-row
+      (should (equal (gloss-display-pick-definition "term" defs) def2)))))
+
+(ert-deftest test-gloss-display-pick-definition-boundary-single-definition ()
+  "Boundary: a single-definition list still returns that plist."
+  (let* ((def '(:source wiktionary :text "Only sense."))
+         (chosen-row (gloss-display--format-candidate def)))
+    (gloss-test--with-completing-read chosen-row
+      (should (equal (gloss-display-pick-definition "term" (list def))
+                     def)))))
+
+(ert-deftest test-gloss-display-pick-definition-boundary-empty-list ()
+  "Boundary: an empty definition list returns nil without prompting."
+  (let ((completing-read-called nil))
+    (cl-letf (((symbol-function 'completing-read)
+               (lambda (&rest _args)
+                 (setq completing-read-called t) "")))
+      (should-not (gloss-display-pick-definition "term" nil))
+      (should-not completing-read-called))))
+
+(ert-deftest test-gloss-display-pick-definition-error-quit-returns-nil ()
+  "Error: C-g during the picker (quit signal) returns nil, not propagate."
+  (let ((def '(:source wiktionary :text "Only sense.")))
+    (gloss-test--with-completing-read quit
+      (should-not (gloss-display-pick-definition "term" (list def))))))
+
+(ert-deftest test-gloss-display-pick-definition-prompt-mentions-term ()
+  "Normal: the completing-read prompt names the term being disambiguated."
+  (let* ((captured-prompt nil)
+         (def '(:source wiktionary :text "Only sense."))
+         (chosen-row (gloss-display--format-candidate def)))
+    (cl-letf (((symbol-function 'completing-read)
+               (lambda (prompt &rest _args)
+                 (setq captured-prompt prompt)
+                 chosen-row)))
+      (gloss-display-pick-definition "anaphora" (list def))
+      (should (string-match-p "anaphora" captured-prompt)))))
+
+(provide 'test-gloss-display--pick-definition)
+;;; test-gloss-display--pick-definition.el ends here