test(org-noter-config): cover preferred-split, slug, template, predicates

Four new test files for the pure-and-near-pure helpers in
org-noter-config.el. The interactive heavyweights (cj/org-noter-start,
cj/org-noter-insert-note-dwim, cj/org-noter--toggle-notes-window,
cj/org-noter--find-notes-file, cj/org-noter--create-notes-file) are
out of scope for this pass — they need org-noter loaded and a real
session, or a substantial internal/wrapper split before they can be
tested without spinning up real PDFs and EPUBs.

- preferred-split: 5 tests walking the 1.4 width-to-height threshold
  from both sides plus a square-frame boundary.
- title-to-slug: 7 tests covering multi-word, single-word, mixed
  punctuation, leading/trailing junk, collapsed runs, digits, and
  empty input.
- generate-notes-template: 5 tests with org-id-uuid mocked, asserting
  the rendered template carries the UUID, the dual ROAM_REFS /
  NOTER_DOCUMENT pointers, the title-and-category lines, the
  ReadingNotes filetag, and the trailing Notes heading.
- predicates: 13 tests covering cj/org-noter--in-document-p,
  cj/org-noter--in-notes-file-p, cj/org-noter--session-active-p,
  cj/org-noter--get-document-path, and cj/org-noter--extract-document-title.
  Mocks derived-mode-p, org-entry-get, and buffer-file-name at the
  boundary so the suite doesn't require pdf-tools or nov.

The require chain in each test file is user-constants → keybindings →
org-noter-config because cj/org-noter-notes-directory captures
roam-dir from user-constants and the prefix-map binding at the bottom
of org-noter-config references cj/custom-keymap.

30 new tests, all passing. Full suite green.

1 files changed, 50 insertions, 0 deletions

diff --git a/tests/test-org-noter-config--title-to-slug.el b/tests/test-org-noter-config--title-to-slug.el
new file mode 100644
index 00000000..3122086d
--- /dev/null
+++ b/tests/test-org-noter-config--title-to-slug.el
@@ -0,0 +1,50 @@
+;;; test-org-noter-config--title-to-slug.el --- Tests for cj/org-noter--title-to-slug -*- lexical-binding: t; -*-
+
+;;; Commentary:
+;; Tests for `cj/org-noter--title-to-slug'. The function lowercases its
+;; input, replaces every run of non-alphanumeric characters with a
+;; single hyphen, and trims leading/trailing hyphens. It's used to
+;; turn a book title into a filename-safe slug.
+
+;;; Code:
+
+(require 'ert)
+
+(add-to-list 'load-path (expand-file-name "modules" user-emacs-directory))
+(require 'user-constants)
+(require 'keybindings)
+(require 'org-noter-config)
+
+(ert-deftest test-org-noter-config-title-to-slug-multi-word ()
+  "Normal: a multi-word title becomes hyphen-separated lowercase."
+  (should (equal "the-pragmatic-programmer"
+                 (cj/org-noter--title-to-slug "The Pragmatic Programmer"))))
+
+(ert-deftest test-org-noter-config-title-to-slug-single-word ()
+  "Normal: a single-word lowercase title is unchanged."
+  (should (equal "anaphora" (cj/org-noter--title-to-slug "anaphora"))))
+
+(ert-deftest test-org-noter-config-title-to-slug-mixed-punctuation ()
+  "Boundary: punctuation is collapsed into single hyphens."
+  (should (equal "godel-escher-bach"
+                 (cj/org-noter--title-to-slug "Godel, Escher, Bach!"))))
+
+(ert-deftest test-org-noter-config-title-to-slug-leading-trailing-non-alnum ()
+  "Boundary: leading and trailing non-alnum runs are trimmed."
+  (should (equal "title"
+                 (cj/org-noter--title-to-slug "  ...title!?? "))))
+
+(ert-deftest test-org-noter-config-title-to-slug-collapses-multiple-non-alnum ()
+  "Boundary: a run of non-alnum chars in the middle becomes one hyphen."
+  (should (equal "a-b" (cj/org-noter--title-to-slug "a   ---   b"))))
+
+(ert-deftest test-org-noter-config-title-to-slug-numbers-preserved ()
+  "Boundary: digits are preserved as-is."
+  (should (equal "1984" (cj/org-noter--title-to-slug "1984"))))
+
+(ert-deftest test-org-noter-config-title-to-slug-empty-string ()
+  "Error: empty input yields empty string."
+  (should (equal "" (cj/org-noter--title-to-slug ""))))
+
+(provide 'test-org-noter-config--title-to-slug)
+;;; test-org-noter-config--title-to-slug.el ends here