content: durable CRDT replication (crdt-store) + 14 tests (277/277)

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 markdown store crdt sync fed)
+SUITES=(block doc render api markdown store crdt crdt-store sync fed)
 
 OUT_JSON="lib/content/scoreboard.json"
 OUT_MD="lib/content/scoreboard.md"
@@ -45,6 +45,7 @@ run_suite() {
 (load "lib/content/markdown.sx")
 (load "lib/content/store.sx")
 (load "lib/content/crdt.sx")
+(load "lib/content/crdt-store.sx")
 (load "lib/content/sync.sx")
 (load "lib/content/fed.sx")
 (epoch 2)

lib/content/crdt-store.sx

@@ -0,0 +1,71 @@
+;; content-on-sx — durable collaborative replication: CRDT ops on persist.
+;;
+;; Each replica appends its CRDT ops to its own persist stream
+;; (crdt:<doc>:<replica>). Any node reconstructs the converged document by
+;; replaying every replica's log into a CvRDT state and merging them. Because
+;; the merge is a join and crdt-apply is order/duplicate-insensitive, the
+;; converged result is identical regardless of replica order or re-delivery —
+;; the durable log + CRDT give offline-capable, eventually-consistent editing.
+;;
+;; Requires (loaded by harness): crdt.sx (+ deps) and persist
+;; (event/backend/log/kv/api). Backend `b` injected via (persist/open).
+
+(define crdt/-stream (fn (doc-id replica) (str "crdt:" doc-id ":" replica)))
+
+;; ── commit ops to a replica's durable log ──
+(define
+  crdt/commit!
+  (fn
+    (b doc-id replica op at)
+    (persist/append b (crdt/-stream doc-id replica) (get op :op) at op)))
+
+(define
+  crdt/commit-all!
+  (fn
+    (b doc-id replica ops at)
+    (if
+      (= (len ops) 0)
+      nil
+      (begin
+        (crdt/commit! b doc-id replica (first ops) at)
+        (crdt/commit-all! b doc-id replica (rest ops) at)))))
+
+;; ── read a replica's log ──
+(define
+  crdt/log
+  (fn (b doc-id replica) (persist/read b (crdt/-stream doc-id replica))))
+
+(define
+  crdt/replica-ops
+  (fn
+    (b doc-id replica)
+    (map (fn (ev) (persist/event-data ev)) (crdt/log b doc-id replica))))
+
+(define
+  crdt/replica-version
+  (fn (b doc-id replica) (persist/last-seq b (crdt/-stream doc-id replica))))
+
+;; ── replay one replica's log into a CvRDT state ──
+(define
+  crdt/replay
+  (fn
+    (b doc-id replica)
+    (crdt-apply-all (crdt-empty) (crdt/replica-ops b doc-id replica))))
+
+;; ── converge: merge every replica's replayed state ──
+(define
+  crdt/converge
+  (fn
+    (b doc-id replicas)
+    (crdt-merge-all (map (fn (r) (crdt/replay b doc-id r)) replicas))))
+
+;; ── converged, materialised document ──
+(define
+  crdt/document
+  (fn
+    (b doc-id replicas)
+    (crdt-materialize doc-id (crdt/converge b doc-id replicas))))
+
+(define
+  crdt/order
+  (fn (b doc-id replicas) (crdt-order (crdt/converge b doc-id replicas))))

lib/content/scoreboard.json

@@ -7,10 +7,11 @@
     "markdown": {"pass": 20, "fail": 0},
     "store": {"pass": 29, "fail": 0},
     "crdt": {"pass": 34, "fail": 0},
+    "crdt-store": {"pass": 14, "fail": 0},
     "sync": {"pass": 14, "fail": 0},
     "fed": {"pass": 20, "fail": 0}
   },
-  "total_pass": 263,
+  "total_pass": 277,
   "total_fail": 0,
-  "total": 263
+  "total": 277
 }

lib/content/scoreboard.md

@@ -11,6 +11,7 @@ _Generated by `lib/content/conformance.sh`_
 | markdown | 20 | 0 | 20 |
 | store | 29 | 0 | 29 |
 | crdt | 34 | 0 | 34 |
+| crdt-store | 14 | 0 | 14 |
 | sync | 14 | 0 | 14 |
 | fed | 20 | 0 | 20 |
-| **Total** | **263** | **0** | **263** |
+| **Total** | **277** | **0** | **277** |

lib/content/tests/crdt-store.sx

@@ -0,0 +1,139 @@
+;; Extension — durable collaborative replication (CRDT ops on persist).
+;; Replicas log independently; converge merges the logs deterministically.
+
+(st-bootstrap-classes!)
+(content-bootstrap-blocks!)
+(content-bootstrap-doc!)
+(content-bootstrap-render!)
+
+(define same? (fn (a b) (= (get a :elements) (get b :elements))))
+(define B (persist/open))
+
+;; replica "a" (origin): inserts h, p
+(crdt/commit!
+  B
+  "doc"
+  "a"
+  (crdt-op-insert
+    "h"
+    "heading"
+    (crdt-pos 1 0)
+    (list (list "level" 1) (list "text" "T"))
+    1
+    1)
+  1)
+(crdt/commit!
+  B
+  "doc"
+  "a"
+  (crdt-op-insert
+    "p"
+    "text"
+    (crdt-pos 2 0)
+    (list (list "text" "Body"))
+    1
+    1)
+  1)
+
+;; replica "b" (concurrent): edits p, inserts x
+(crdt/commit-all!
+  B
+  "doc"
+  "b"
+  (list
+    (crdt-op-update "p" "text" "Edited" 5 2)
+    (crdt-op-insert
+      "x"
+      "text"
+      (crdt-pos 3 0)
+      (list (list "text" "X"))
+      6
+      2))
+  5)
+
+;; ── durability ──
+(content-test
+  "replica a version"
+  (crdt/replica-version B "doc" "a")
+  2)
+(content-test
+  "replica b version"
+  (crdt/replica-version B "doc" "b")
+  2)
+(content-test
+  "replica a ops len"
+  (len (crdt/replica-ops B "doc" "a"))
+  2)
+
+;; ── single-replica replay ──
+(content-test
+  "replay a order"
+  (crdt-order (crdt/replay B "doc" "a"))
+  (list "h" "p"))
+(content-test
+  "replay a == apply-all"
+  (same?
+    (crdt/replay B "doc" "a")
+    (crdt-apply-all (crdt-empty) (crdt/replica-ops B "doc" "a")))
+  true)
+
+;; ── converge ──
+(content-test
+  "converge order"
+  (crdt/order B "doc" (list "a" "b"))
+  (list "h" "p" "x"))
+(content-test
+  "converge replica-order-independent"
+  (same?
+    (crdt/converge B "doc" (list "a" "b"))
+    (crdt/converge B "doc" (list "b" "a")))
+  true)
+(content-test
+  "converge LWW p edited"
+  (str
+    (blk-send (doc-find (crdt/document B "doc" (list "a" "b")) "p") "text"))
+  "Edited")
+(content-test
+  "converged document render"
+  (asHTML (crdt/document B "doc" (list "a" "b")))
+  "<h1>T</h1><p>Edited</p><p>X</p>")
+
+;; ── duplicate delivery is idempotent ──
+(crdt/commit!
+  B
+  "doc"
+  "a"
+  (crdt-op-insert
+    "p"
+    "text"
+    (crdt-pos 2 0)
+    (list (list "text" "Body"))
+    1
+    1)
+  1)
+(content-test
+  "duplicate op no effect on converge"
+  (crdt/order B "doc" (list "a" "b"))
+  (list "h" "p" "x"))
+(content-test
+  "duplicate keeps LWW value"
+  (str
+    (blk-send (doc-find (crdt/document B "doc" (list "a" "b")) "p") "text"))
+  "Edited")
+
+;; ── new op on a replica is reflected after re-converge ──
+(crdt/commit! B "doc" "b" (crdt-op-delete "h") 9)
+(content-test
+  "delete reflected after reconverge"
+  (crdt/order B "doc" (list "a" "b"))
+  (list "p" "x"))
+
+;; ── isolation: unknown doc converges to empty ──
+(content-test
+  "unknown doc empty"
+  (crdt/order B "other" (list "a" "b"))
+  (list))
+(content-test
+  "unknown replica empty ops"
+  (len (crdt/replica-ops B "doc" "zzz"))
+  0)