content: document normalization (normalize.sx) + 11 tests (605/605)

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 page-full markdown text section compose tree-edit clone query toc transform stats table data wire validate store snapshot crdt crdt-store sync md-import md-doc fed)
+SUITES=(block doc render api meta page page-full markdown text section compose tree-edit clone query toc transform normalize stats table data wire validate store snapshot crdt crdt-store sync md-import md-doc fed)
 
 OUT_JSON="lib/content/scoreboard.json"
 OUT_MD="lib/content/scoreboard.md"
@@ -51,6 +51,7 @@ run_suite() {
 (load "lib/content/query.sx")
 (load "lib/content/toc.sx")
 (load "lib/content/transform.sx")
+(load "lib/content/normalize.sx")
 (load "lib/content/stats.sx")
 (load "lib/content/table.sx")
 (load "lib/content/data.sx")

lib/content/normalize.sx

@@ -0,0 +1,49 @@
+;; content-on-sx — document normalization.
+;;
+;; A cleanup pass: drop empty text blocks and empty sections across the tree.
+;; Sections are normalised first, so a section that becomes empty (all children
+;; dropped) is itself dropped. For tidying imported/edited documents. Immutable.
+;; Inline tree handling (no section.sx dep).
+;;
+;; Requires (loaded by harness): block.sx, doc.sx.
+
+(define
+  norm-section?
+  (fn (b) (and (st-instance? b) (= (get b :class) "CtSection"))))
+(define
+  norm-empty-text?
+  (fn (b) (and (= (blk-type b) "text") (= (str (blk-get b "text")) ""))))
+(define
+  norm-empty-section?
+  (fn
+    (b)
+    (and
+      (norm-section? b)
+      (let
+        ((ch (st-iv-get b "children")))
+        (or (= ch nil) (= (len ch) 0))))))
+
+(define
+  norm-recurse
+  (fn
+    (b)
+    (if
+      (norm-section? b)
+      (let
+        ((ch (st-iv-get b "children")))
+        (if (list? ch) (st-iv-set! b "children" (norm-blocks ch)) b))
+      b)))
+
+(define
+  norm-keep?
+  (fn
+    (b)
+    (if (norm-empty-text? b) false (if (norm-empty-section? b) false true))))
+
+(define
+  norm-blocks
+  (fn (blocks) (filter norm-keep? (map norm-recurse blocks))))
+
+(define
+  content/normalize
+  (fn (doc) (doc-with-blocks doc (norm-blocks (doc-blocks doc)))))

lib/content/scoreboard.json

@@ -16,6 +16,7 @@
     "query": {"pass": 13, "fail": 0},
     "toc": {"pass": 8, "fail": 0},
     "transform": {"pass": 12, "fail": 0},
+    "normalize": {"pass": 11, "fail": 0},
     "stats": {"pass": 17, "fail": 0},
     "table": {"pass": 15, "fail": 0},
     "data": {"pass": 21, "fail": 0},
@@ -30,7 +31,7 @@
     "md-doc": {"pass": 12, "fail": 0},
     "fed": {"pass": 20, "fail": 0}
   },
-  "total_pass": 594,
+  "total_pass": 605,
   "total_fail": 0,
-  "total": 594
+  "total": 605
 }

lib/content/scoreboard.md

@@ -20,6 +20,7 @@ _Generated by `lib/content/conformance.sh`_
 | query | 13 | 0 | 13 |
 | toc | 8 | 0 | 8 |
 | transform | 12 | 0 | 12 |
+| normalize | 11 | 0 | 11 |
 | stats | 17 | 0 | 17 |
 | table | 15 | 0 | 15 |
 | data | 21 | 0 | 21 |
@@ -33,4 +34,4 @@ _Generated by `lib/content/conformance.sh`_
 | md-import | 38 | 0 | 38 |
 | md-doc | 12 | 0 | 12 |
 | fed | 20 | 0 | 20 |
-| **Total** | **594** | **0** | **594** |
+| **Total** | **605** | **0** | **605** |

lib/content/tests/normalize.sx

@@ -0,0 +1,99 @@
+;; Extension — document normalization (drop empty text blocks + empty sections).
+
+(st-bootstrap-classes!)
+(content/bootstrap!)
+(content-bootstrap-section!)
+
+;; ── drop empty text blocks ──
+(define
+  d
+  (doc-append
+    (doc-append
+      (doc-append (doc-empty "d") (mk-heading "h" 1 "Hi"))
+      (mk-text "empty" ""))
+    (mk-text "p" "Body")))
+(content-test
+  "drops empty text"
+  (doc-ids (content/normalize d))
+  (list "h" "p"))
+(content-test "normalize immutable" (doc-ids d) (list "h" "empty" "p"))
+(content-test
+  "keeps non-empty text"
+  (str (blk-send (doc-find (content/normalize d) "p") "text"))
+  "Body")
+
+;; ── drop empty sections ──
+(define
+  d2
+  (doc-append
+    (doc-append (doc-empty "d") (mk-text "p" "x"))
+    (mk-section "empty-sec" (list))))
+(content-test
+  "drops empty section"
+  (doc-ids (content/normalize d2))
+  (list "p"))
+
+;; ── section that becomes empty (all children dropped) is itself dropped ──
+(define
+  d3
+  (doc-append
+    (doc-empty "d")
+    (mk-section "s" (list (mk-text "e1" "") (mk-text "e2" "")))))
+(content-test
+  "section emptied then dropped"
+  (doc-ids (content/normalize d3))
+  (list))
+
+;; ── section with some content keeps surviving children ──
+(define
+  d4
+  (doc-append
+    (doc-empty "d")
+    (mk-section
+      "s"
+      (list (mk-text "e" "") (mk-heading "k" 2 "Keep")))))
+(define n4 (content/normalize d4))
+(content-test "section kept" (doc-ids n4) (list "s"))
+(content-test
+  "empty child dropped, real kept"
+  (doc-tree-ids n4)
+  (list "s" "k"))
+
+;; ── nested: empty deep section removed, content bubbles correctly ──
+(define
+  d5
+  (doc-append
+    (doc-empty "d")
+    (mk-section
+      "outer"
+      (list (mk-text "a" "A") (mk-section "inner" (list (mk-text "x" "")))))))
+(content-test
+  "nested empty inner dropped"
+  (doc-tree-ids (content/normalize d5))
+  (list "outer" "a"))
+
+;; ── already-clean doc unchanged ──
+(define
+  clean
+  (doc-append
+    (doc-append (doc-empty "d") (mk-heading "h" 1 "T"))
+    (mk-text "p" "B")))
+(content-test
+  "clean doc unchanged ids"
+  (doc-ids (content/normalize clean))
+  (list "h" "p"))
+(content-test
+  "clean doc render"
+  (asHTML (content/normalize clean))
+  (asHTML clean))
+
+;; ── non-text empties preserved (divider, image with empty alt) ──
+(define
+  d6
+  (doc-append
+    (doc-append (doc-empty "d") (mk-divider "dv"))
+    (mk-image "i" "/a.png" "")))
+(content-test
+  "divider + image kept"
+  (doc-ids (content/normalize d6))
+  (list "dv" "i"))

plans/content-on-sx.md

@@ -19,7 +19,7 @@ injected adapter, not core.
 
 ## Status (rolling)
 
-`bash lib/content/conformance.sh` → **594/594** (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 + deep tree editing, doc stats, table block, HTML page wrapper + SEO page, doc composition + id-remap, portable data + wire serialization, block query + transforms, TOC rendering)
+`bash lib/content/conformance.sh` → **605/605** (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 + deep tree editing, doc stats, table block, HTML page wrapper + SEO page, doc composition + id-remap, portable data + wire serialization, block query + transforms, TOC rendering, normalization)
 
 ## Ground rules
 
@@ -97,11 +97,17 @@ lib/content/api.sx ── (content/edit) (content/render) (content/history) ─
 - [x] block query + TOC (`query.sx`: content/select/select-type/count-type/headings)
 - [x] block transforms (`transform.sx`: content/map-blocks/map-type/set-field-on)
 - [x] TOC rendering (`toc.sx`: content/toc-markdown + toc-html from headings)
+- [x] document normalization (`normalize.sx`: content/normalize, drop empty blocks/sections)
 - [x] portable data serialization (`data.sx`: content/to-data + from-data, round-trips tree)
 - [x] wire serialization (`wire.sx`: content/to-wire + from-wire, SX-text on the wire)
 
 ## Progress log
 
+- 2026-06-07 — Extension: document normalization (`normalize.sx`).
+  `content/normalize` drops empty text blocks and empty sections tree-wide;
+  sections are normalised first so one emptied by the pass is itself removed.
+  For tidying imported/edited docs; non-text empties (dividers, blank-alt images)
+  preserved. Inline tree handling; immutable. 11 tests; suite 605/605.
 - 2026-06-07 — Extension: table-of-contents rendering (`toc.sx`).
   `content/toc-markdown` produces a Markdown bullet list indented by heading
   level with `[text](#id)` links; `content/toc-html` produces a `<ul>` of escaped