content: TOC rendering (toc.sx) + 8 tests (594/594)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

lib/content/tests/toc.sx

@@ -0,0 +1,63 @@
+;; Extension — table-of-contents rendering.
+
+(st-bootstrap-classes!)
+(content/bootstrap!)
+(content-bootstrap-section!)
+
+(define nl (str "\n"))
+
+(define
+  d
+  (doc-append
+    (doc-append
+      (doc-append
+        (doc-append (doc-empty "d") (mk-heading "intro" 1 "Intro"))
+        (mk-text "p" "x"))
+      (mk-heading "bg" 2 "Background"))
+    (mk-section "s" (list (mk-heading "deep" 2 "Details")))))
+
+;; ── markdown TOC (indented by level) ──
+(content-test
+  "toc markdown"
+  (content/toc-markdown d)
+  (str
+    "- [Intro](#intro)"
+    nl
+    "  - [Background](#bg)"
+    nl
+    "  - [Details](#deep)"))
+
+;; ── html TOC (anchor links) ──
+(content-test
+  "toc html"
+  (content/toc-html d)
+  "<ul><li><a href=\"#intro\">Intro</a></li><li><a href=\"#bg\">Background</a></li><li><a href=\"#deep\">Details</a></li></ul>")
+
+;; ── html escapes heading text ──
+(content-test
+  "toc html escapes"
+  (content/toc-html
+    (doc-append (doc-empty "d") (mk-heading "h" 1 "A < B")))
+  "<ul><li><a href=\"#h\">A &lt; B</a></li></ul>")
+
+;; ── empty / no headings ──
+(content-test "toc html empty" (content/toc-html (doc-empty "e")) "")
+(content-test "toc markdown empty" (content/toc-markdown (doc-empty "e")) "")
+(content-test
+  "toc no headings"
+  (content/toc-html (doc-append (doc-empty "d") (mk-text "p" "just text")))
+  "")
+
+;; ── single heading ──
+(content-test
+  "toc single md"
+  (content/toc-markdown
+    (doc-append (doc-empty "d") (mk-heading "h" 1 "Only")))
+  "- [Only](#h)")
+
+;; ── deep level indentation ──
+(content-test
+  "toc deep indent"
+  (content/toc-markdown
+    (doc-append (doc-empty "d") (mk-heading "h" 3 "Deep")))
+  "    - [Deep](#h)")