content: Markdown doc export w/ frontmatter (md-doc.sx) + 12 tests (481/481)

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

lib/content/conformance.sh

@@ -15,7 +15,7 @@ if [ ! -x "$SX_SERVER" ]; then
   fi
 fi
 
-SUITES=(block doc render api meta page markdown text section stats table validate store snapshot crdt crdt-store sync md-import fed)
+SUITES=(block doc render api meta page markdown text section stats table validate store snapshot crdt crdt-store sync md-import md-doc fed)
 
 OUT_JSON="lib/content/scoreboard.json"
 OUT_MD="lib/content/scoreboard.md"
@@ -56,6 +56,7 @@ run_suite() {
 (load "lib/content/crdt-store.sx")
 (load "lib/content/sync.sx")
 (load "lib/content/md-import.sx")
+(load "lib/content/md-doc.sx")
 (load "lib/content/fed.sx")
 (epoch 2)
 (eval "(define content-test-pass 0)")

lib/content/md-doc.sx

@@ -0,0 +1,63 @@
+;; content-on-sx — Markdown document export (frontmatter + body).
+;;
+;; content/markdown-doc emits a YAML-ish --- frontmatter block from the document
+;; metadata (title/slug/tags) followed by the Markdown body, completing the
+;; metadata round-trip with md/import (md/import ∘ content/markdown-doc keeps
+;; title/slug/tags). With no metadata it is just asMarkdown.
+;;
+;; Requires (loaded by harness): doc.sx, meta.sx (doc-title/slug/tags),
+;; markdown.sx (asMarkdown).
+
+(define mdd-nl (str "\n"))
+
+(define
+  mdd-join
+  (fn
+    (sep parts)
+    (cond
+      ((= (len parts) 0) "")
+      ((= (len parts) 1) (first parts))
+      (else (str (first parts) sep (mdd-join sep (rest parts)))))))
+
+(define
+  content/-fm-parts
+  (fn
+    (doc)
+    (append
+      (append
+        (if
+          (= (doc-title doc) nil)
+          (list)
+          (list (str "title: " (doc-title doc))))
+        (if
+          (= (doc-slug doc) nil)
+          (list)
+          (list (str "slug: " (doc-slug doc)))))
+      (let
+        ((tags (doc-tags doc)))
+        (if
+          (= (len tags) 0)
+          (list)
+          (list (str "tags: " (mdd-join ", " tags))))))))
+
+(define
+  content/-frontmatter
+  (fn
+    (doc)
+    (let
+      ((parts (content/-fm-parts doc)))
+      (if
+        (= (len parts) 0)
+        ""
+        (str "---" mdd-nl (mdd-join mdd-nl parts) mdd-nl "---")))))
+
+(define
+  content/markdown-doc
+  (fn
+    (doc)
+    (let
+      ((fm (content/-frontmatter doc)))
+      (if
+        (= fm "")
+        (asMarkdown doc)
+        (str fm mdd-nl mdd-nl (asMarkdown doc))))))

lib/content/scoreboard.json

@@ -18,9 +18,10 @@
     "crdt-store": {"pass": 14, "fail": 0},
     "sync": {"pass": 14, "fail": 0},
     "md-import": {"pass": 38, "fail": 0},
+    "md-doc": {"pass": 12, "fail": 0},
     "fed": {"pass": 20, "fail": 0}
   },
-  "total_pass": 469,
+  "total_pass": 481,
   "total_fail": 0,
-  "total": 469
+  "total": 481
 }

lib/content/scoreboard.md

@@ -22,5 +22,6 @@ _Generated by `lib/content/conformance.sh`_
 | crdt-store | 14 | 0 | 14 |
 | sync | 14 | 0 | 14 |
 | md-import | 38 | 0 | 38 |
+| md-doc | 12 | 0 | 12 |
 | fed | 20 | 0 | 20 |
-| **Total** | **469** | **0** | **469** |
+| **Total** | **481** | **0** | **481** |

lib/content/tests/md-doc.sx

@@ -0,0 +1,71 @@
+;; Extension — Markdown document export (frontmatter + body), round-trips with
+;; md/import including metadata.
+
+(st-bootstrap-classes!)
+(content/bootstrap!)
+(content-bootstrap-markdown!)
+(content-bootstrap-table!)
+
+(define nl (str "\n"))
+
+;; ── no metadata → plain markdown (no frontmatter) ──
+(define plain (doc-append (doc-empty "d") (mk-heading "h" 1 "Hi")))
+(content-test
+  "no-meta == asMarkdown"
+  (content/markdown-doc plain)
+  (asMarkdown plain))
+(content-test "no-meta no frontmatter" (content/markdown-doc plain) "# Hi")
+
+;; ── full metadata frontmatter ──
+(define
+  d
+  (doc-with-meta
+    (doc-append (doc-empty "post") (mk-heading "h" 1 "Hi"))
+    {:slug "my-post" :title "My Post" :tags (list "a" "b")}))
+(content-test
+  "frontmatter export"
+  (content/markdown-doc d)
+  (str
+    "---"
+    nl
+    "title: My Post"
+    nl
+    "slug: my-post"
+    nl
+    "tags: a, b"
+    nl
+    "---"
+    nl
+    nl
+    "# Hi"))
+
+;; ── title only ──
+(content-test
+  "title-only frontmatter"
+  (content/markdown-doc
+    (doc-with-title (doc-append (doc-empty "p") (mk-text "x" "body")) "T"))
+  (str "---" nl "title: T" nl "---" nl nl "body"))
+
+;; ── round-trip: import . export keeps metadata + blocks ──
+(define rt (md/import (content/markdown-doc d) "post"))
+(content-test "round-trip title" (doc-title rt) "My Post")
+(content-test "round-trip slug" (doc-slug rt) "my-post")
+(content-test "round-trip tags" (doc-tags rt) (list "a" "b"))
+(content-test "round-trip body" (doc-types rt) (list "heading"))
+(content-test
+  "round-trip body text"
+  (str (blk-send (doc-find rt "b0") "text"))
+  "Hi")
+
+;; ── round-trip a richer doc ──
+(define
+  d2
+  (doc-with-meta
+    (doc-append
+      (doc-append (doc-empty "p") (mk-heading "h" 2 "Title"))
+      (mk-text "p" "para text"))
+    {:title "Big" :tags (list "x")}))
+(define rt2 (md/import (content/markdown-doc d2) "p"))
+(content-test "rt2 title" (doc-title rt2) "Big")
+(content-test "rt2 tags" (doc-tags rt2) (list "x"))
+(content-test "rt2 types" (doc-types rt2) (list "heading" "text"))

plans/content-on-sx.md

@@ -19,7 +19,7 @@ injected adapter, not core.
 
 ## Status (rolling)
 
-`bash lib/content/conformance.sh` → **469/469** (Phases 1–4 COMPLETE + 13 extensions: HTML/SX escaping, Markdown render + import incl. tables & frontmatter, CRDT replication, tree-aware validation, snapshot cache, doc metadata, plain-text render, nested block trees, doc stats, table block, HTML page wrapper)
+`bash lib/content/conformance.sh` → **481/481** (Phases 1–4 COMPLETE + extensions: HTML/SX escaping, Markdown render + import/export incl. tables & frontmatter (full round-trip), CRDT replication, tree-aware validation, snapshot cache, doc metadata, plain-text render, nested block trees, doc stats, table block, HTML page wrapper)
 
 ## Ground rules
 
@@ -82,6 +82,7 @@ lib/content/api.sx ── (content/edit) (content/render) (content/history) ─
 - [x] durable CRDT replication (`crdt-store.sx`: ops on persist, replay + converge)
 - [x] document validation (`validate.sx`: ids, per-type fields, duplicate ids; tree-aware — descends into sections, tree-wide dup ids, section field check)
 - [x] Markdown import adapter (`md-import.sx`: text → blocks, round-trips export; incl. pipe tables + frontmatter → metadata)
+- [x] Markdown doc export (`md-doc.sx`: content/markdown-doc, frontmatter from metadata, full round-trip)
 - [x] snapshot cache over replay (`snapshot.sx`: cache-not-primary, transparent)
 - [x] document metadata (`meta.sx`: title/slug/tags + Ghost title plumbing)
 - [x] plain-text render + excerpt (`text.sx`: asText, content/excerpt)
@@ -92,6 +93,12 @@ lib/content/api.sx ── (content/edit) (content/render) (content/history) ─
 
 ## Progress log
 
+- 2026-06-07 — Extension: Markdown document export (`md-doc.sx`).
+  `content/markdown-doc` emits a `---` frontmatter block from metadata
+  (title/slug/tags, only present fields) ahead of the Markdown body, or plain
+  asMarkdown when there's no metadata. Completes the metadata round-trip:
+  `md/import ∘ content/markdown-doc` preserves title/slug/tags + blocks. 12
+  tests; suite 481/481.
 - 2026-06-07 — Extension: Markdown frontmatter. `md/import` parses a leading
   `---` / `key: value` / `---` block into document metadata (title, slug,
   comma-separated tags via `doc-with-meta`) before parsing the body; a `---`