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

Four test files plus a small testutil for toggling the `org-drill'
feature flag. All 10 tests fail at this commit because the implementation
is still a stub.

The suite covers Normal (untagged entries get the tag and property),
Boundary (empty file, idempotency, untag never-tagged), and Error
(org-drill not installed). The error path also asserts the file is left
untouched. Untag-all is tested under both feature states because the
user might want to remove tags after uninstalling org-drill.

5 files changed, 260 insertions, 0 deletions

diff --git a/tests/test-gloss-drill--export-all-no-orgdrill-installed.el b/tests/test-gloss-drill--export-all-no-orgdrill-installed.el
new file mode 100644
index 0000000..f8f4967
--- /dev/null
+++ b/tests/test-gloss-drill--export-all-no-orgdrill-installed.el
@@ -0,0 +1,38 @@
+;;; test-gloss-drill--export-all-no-orgdrill-installed.el --- Error tests for missing org-drill -*- lexical-binding: t -*-
+
+;; SPDX-License-Identifier: GPL-3.0-or-later
+
+;;; Commentary:
+;; Tests for `gloss-drill-export-all' covering the Error case where
+;; `org-drill' is not installed.  The function must raise `user-error'
+;; with an install hint and must not touch `gloss-file'.
+
+;;; Code:
+
+(require 'ert)
+(require 'gloss-drill)
+(require 'testutil-gloss)
+(require 'testutil-gloss-drill)
+
+(ert-deftest test-gloss-drill-export-all-without-org-drill-raises-user-error ()
+  "Error: missing `org-drill' raises `user-error' with an install hint."
+  (gloss-test--with-temp-glossary gloss-test--sample-content
+    (gloss-test--without-org-drill-feature
+      (let ((err (should-error (gloss-drill-export-all) :type 'user-error)))
+        (should (string-match-p "org-drill" (error-message-string err)))))))
+
+(ert-deftest test-gloss-drill-export-all-without-org-drill-leaves-file-untouched ()
+  "Error: missing `org-drill' must not modify the glossary file."
+  (gloss-test--with-temp-glossary gloss-test--sample-content
+    (gloss-test--without-org-drill-feature
+      (let ((before (with-temp-buffer
+                      (insert-file-contents gloss-file)
+                      (buffer-string))))
+        (ignore-errors (gloss-drill-export-all))
+        (let ((after (with-temp-buffer
+                       (insert-file-contents gloss-file)
+                       (buffer-string))))
+          (should (equal before after)))))))
+
+(provide 'test-gloss-drill--export-all-no-orgdrill-installed)
+;;; test-gloss-drill--export-all-no-orgdrill-installed.el ends here
diff --git a/tests/test-gloss-drill--export-all-skips-already-tagged.el b/tests/test-gloss-drill--export-all-skips-already-tagged.el
new file mode 100644
index 0000000..52978c6
--- /dev/null
+++ b/tests/test-gloss-drill--export-all-skips-already-tagged.el
@@ -0,0 +1,60 @@
+;;; test-gloss-drill--export-all-skips-already-tagged.el --- Idempotency tests for gloss-drill-export-all -*- lexical-binding: t -*-
+
+;; SPDX-License-Identifier: GPL-3.0-or-later
+
+;;; Commentary:
+;; Tests for `gloss-drill-export-all' covering the Boundary case of
+;; running export twice in a row.  Running it on an already-tagged
+;; entry must not duplicate the :drill: tag, and the
+;; :DRILL_CARD_TYPE: twosided property must remain a single property
+;; with the same value.
+
+;;; Code:
+
+(require 'ert)
+(require 'gloss-drill)
+(require 'testutil-gloss)
+(require 'testutil-gloss-drill)
+
+(defun gloss-test--drill-tag-count-on-first-entry ()
+  "Return how many times \"drill\" appears in the first entry's tag list.
+Reads the file fresh from disk."
+  (with-current-buffer (find-file-noselect gloss-file)
+    (revert-buffer t t t)
+    (let ((count 0))
+      (org-map-entries
+       (lambda ()
+         (when (= 1 (org-current-level))
+           (setq count (length (cl-remove-if-not
+                                (lambda (tag) (equal tag "drill"))
+                                (org-get-tags nil t))))
+           (throw 'done nil))))
+      count)))
+
+(ert-deftest test-gloss-drill-export-all-idempotent-tag-not-duplicated ()
+  "Boundary: running export-all twice does not duplicate the :drill: tag."
+  (gloss-test--with-temp-glossary gloss-test--sample-content
+    (gloss-test--with-org-drill-feature
+      (gloss-drill-export-all)
+      (gloss-drill-export-all)
+      (catch 'done
+        (should (= (gloss-test--drill-tag-count-on-first-entry) 1))))))
+
+(ert-deftest test-gloss-drill-export-all-idempotent-property-unchanged ()
+  "Boundary: running export-all twice keeps :DRILL_CARD_TYPE: twosided."
+  (gloss-test--with-temp-glossary gloss-test--sample-content
+    (gloss-test--with-org-drill-feature
+      (gloss-drill-export-all)
+      (gloss-drill-export-all)
+      (with-current-buffer (find-file-noselect gloss-file)
+        (revert-buffer t t t)
+        (catch 'done
+          (org-map-entries
+           (lambda ()
+             (when (= 1 (org-current-level))
+               (should (equal (org-entry-get nil "DRILL_CARD_TYPE")
+                              "twosided"))
+               (throw 'done nil)))))))))
+
+(provide 'test-gloss-drill--export-all-skips-already-tagged)
+;;; test-gloss-drill--export-all-skips-already-tagged.el ends here
diff --git a/tests/test-gloss-drill--export-all-tags-untagged.el b/tests/test-gloss-drill--export-all-tags-untagged.el
new file mode 100644
index 0000000..bf8cf64
--- /dev/null
+++ b/tests/test-gloss-drill--export-all-tags-untagged.el
@@ -0,0 +1,66 @@
+;;; test-gloss-drill--export-all-tags-untagged.el --- Tests for gloss-drill-export-all on untagged entries -*- lexical-binding: t -*-
+
+;; SPDX-License-Identifier: GPL-3.0-or-later
+
+;;; Commentary:
+;; Tests for `gloss-drill-export-all' covering the Normal happy-path
+;; (untagged entries gain the tag and property) and the Boundary case of
+;; an empty glossary file.  The entry walking uses real `org-element' /
+;; `org-map-entries'; only the `org-drill' feature flag is mocked.
+
+;;; Code:
+
+(require 'ert)
+(require 'gloss-drill)
+(require 'testutil-gloss)
+(require 'testutil-gloss-drill)
+
+(defun gloss-test--drill-tagged-count ()
+  "Return the number of top-level entries in `gloss-file' tagged :drill:.
+Reads the file fresh from disk."
+  (with-current-buffer (find-file-noselect gloss-file)
+    (revert-buffer t t t)
+    (let ((count 0))
+      (org-map-entries
+       (lambda ()
+         (when (and (= 1 (org-current-level))
+                    (member "drill" (org-get-tags nil t)))
+           (setq count (1+ count)))))
+      count)))
+
+(defun gloss-test--drill-card-type-count ()
+  "Return the number of top-level entries with :DRILL_CARD_TYPE: twosided'.
+Reads the file fresh from disk."
+  (with-current-buffer (find-file-noselect gloss-file)
+    (revert-buffer t t t)
+    (let ((count 0))
+      (org-map-entries
+       (lambda ()
+         (when (and (= 1 (org-current-level))
+                    (equal (org-entry-get nil "DRILL_CARD_TYPE") "twosided"))
+           (setq count (1+ count)))))
+      count)))
+
+(ert-deftest test-gloss-drill-export-all-adds-drill-tag-to-every-entry ()
+  "Normal: every untagged entry gains :drill: after export-all."
+  (gloss-test--with-temp-glossary gloss-test--sample-content
+    (gloss-test--with-org-drill-feature
+      (gloss-drill-export-all)
+      (should (= (gloss-test--drill-tagged-count) 2)))))
+
+(ert-deftest test-gloss-drill-export-all-sets-drill-card-type-property ()
+  "Normal: every entry gains :DRILL_CARD_TYPE: twosided after export-all."
+  (gloss-test--with-temp-glossary gloss-test--sample-content
+    (gloss-test--with-org-drill-feature
+      (gloss-drill-export-all)
+      (should (= (gloss-test--drill-card-type-count) 2)))))
+
+(ert-deftest test-gloss-drill-export-all-empty-file-no-op ()
+  "Boundary: export-all on an empty glossary file is a no-op, no error."
+  (gloss-test--with-temp-glossary "#+TITLE: Glossary\n#+STARTUP: showall\n"
+    (gloss-test--with-org-drill-feature
+      (gloss-drill-export-all)
+      (should (= (gloss-test--drill-tagged-count) 0)))))
+
+(provide 'test-gloss-drill--export-all-tags-untagged)
+;;; test-gloss-drill--export-all-tags-untagged.el ends here
diff --git a/tests/test-gloss-drill--untag-all.el b/tests/test-gloss-drill--untag-all.el
new file mode 100644
index 0000000..7fe9986
--- /dev/null
+++ b/tests/test-gloss-drill--untag-all.el
@@ -0,0 +1,56 @@
+;;; test-gloss-drill--untag-all.el --- Tests for gloss-drill-untag-all -*- lexical-binding: t -*-
+
+;; SPDX-License-Identifier: GPL-3.0-or-later
+
+;;; Commentary:
+;; Tests for `gloss-drill-untag-all' covering Normal (export then untag),
+;; Boundary (untag when nothing was tagged), and the no-org-drill-needed
+;; case (untag must work without `org-drill' installed, since the user
+;; might want to remove tags after uninstalling).
+
+;;; Code:
+
+(require 'ert)
+(require 'gloss-drill)
+(require 'testutil-gloss)
+(require 'testutil-gloss-drill)
+
+(defun gloss-test--no-drill-tags-or-properties-p ()
+  "Return non-nil when no top-level entry carries :drill: or DRILL_CARD_TYPE.
+Reads the file fresh from disk."
+  (with-current-buffer (find-file-noselect gloss-file)
+    (revert-buffer t t t)
+    (let ((dirty nil))
+      (org-map-entries
+       (lambda ()
+         (when (= 1 (org-current-level))
+           (when (or (member "drill" (org-get-tags nil t))
+                     (org-entry-get nil "DRILL_CARD_TYPE"))
+             (setq dirty t)))))
+      (not dirty))))
+
+(ert-deftest test-gloss-drill-untag-all-removes-tag-and-property ()
+  "Normal: untag-all removes :drill: and :DRILL_CARD_TYPE: from every entry."
+  (gloss-test--with-temp-glossary gloss-test--sample-content
+    (gloss-test--with-org-drill-feature
+      (gloss-drill-export-all)
+      (gloss-drill-untag-all)
+      (should (gloss-test--no-drill-tags-or-properties-p)))))
+
+(ert-deftest test-gloss-drill-untag-all-no-op-when-nothing-tagged ()
+  "Boundary: untag-all on never-tagged entries is a no-op, no error."
+  (gloss-test--with-temp-glossary gloss-test--sample-content
+    (gloss-drill-untag-all)
+    (should (gloss-test--no-drill-tags-or-properties-p))))
+
+(ert-deftest test-gloss-drill-untag-all-works-without-org-drill-installed ()
+  "Boundary: untag-all does NOT require org-drill to be installed."
+  (gloss-test--with-temp-glossary gloss-test--sample-content
+    (gloss-test--with-org-drill-feature
+      (gloss-drill-export-all))
+    (gloss-test--without-org-drill-feature
+      (gloss-drill-untag-all)
+      (should (gloss-test--no-drill-tags-or-properties-p)))))
+
+(provide 'test-gloss-drill--untag-all)
+;;; test-gloss-drill--untag-all.el ends here
diff --git a/tests/testutil-gloss-drill.el b/tests/testutil-gloss-drill.el
new file mode 100644
index 0000000..721922c
--- /dev/null
+++ b/tests/testutil-gloss-drill.el
@@ -0,0 +1,40 @@
+;;; testutil-gloss-drill.el --- Shared test fixtures for gloss-drill -*- lexical-binding: t -*-
+
+;; SPDX-License-Identifier: GPL-3.0-or-later
+
+;;; Commentary:
+
+;; Fixtures used across `gloss-drill' test files.  Provides:
+;;   - `gloss-test--with-org-drill-feature' macro to register `org-drill'
+;;     as a feature for the duration of BODY (without actually loading it).
+
+;;; Code:
+
+(defmacro gloss-test--with-org-drill-feature (&rest body)
+  "Run BODY with `org-drill' provided as a feature.
+Restores the prior feature state on exit so tests can both assert
+\"org-drill present\" and \"org-drill absent\" behaviour without leaking
+state across the suite."
+  (declare (indent 0) (debug t))
+  `(let ((had-org-drill (featurep 'org-drill)))
+     (unwind-protect
+         (progn
+           (provide 'org-drill)
+           ,@body)
+       (unless had-org-drill
+         (setq features (delq 'org-drill features))))))
+
+(defmacro gloss-test--without-org-drill-feature (&rest body)
+  "Run BODY with `org-drill' un-registered as a feature.
+Restores the prior feature state on exit."
+  (declare (indent 0) (debug t))
+  `(let ((had-org-drill (featurep 'org-drill)))
+     (unwind-protect
+         (progn
+           (setq features (delq 'org-drill features))
+           ,@body)
+       (when had-org-drill
+         (provide 'org-drill)))))
+
+(provide 'testutil-gloss-drill)
+;;; testutil-gloss-drill.el ends here