persist: atomic batch append — contiguous block + transactional guard + 10 tests

batch.sx: persist/append-batch commits (type at data) specs as one contiguous block; persist/append-batch-expect checks the stream is still at expected before writing any event, so the batch is all-or-nothing under a concurrent writer (conflict is a value, not a partial write). 162/162. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-06 19:24:35 +00:00
parent 4e521e3d7a
commit 62a1485302
6 changed files with 180 additions and 5 deletions
--- a/lib/persist/tests/batch.sx
+++ b/lib/persist/tests/batch.sx
@@ -0,0 +1,122 @@
+; Extension — atomic batch append: contiguous seqs, transactional all-or-nothing.
+
+(persist-test
+  "batch assigns contiguous seqs"
+  (let
+    ((b (persist/open)))
+    (let
+      ((evs (persist/append-batch b "s" (list (list "a" 0 {}) (list "b" 0 {}) (list "c" 0 {})))))
+      (list
+        (persist/event-seq (first evs))
+        (persist/event-seq (nth evs 2)))))
+  (list 1 3))
+(persist-test
+  "batch returns events in order"
+  (let
+    ((b (persist/open)))
+    (let
+      ((evs (persist/append-batch b "s" (list (list "a" 0 {}) (list "b" 0 {})))))
+      (list
+        (persist/event-type (first evs))
+        (persist/event-type (nth evs 1)))))
+  (list "a" "b"))
+(persist-test
+  "batch grows the stream by its size"
+  (let
+    ((b (persist/open)))
+    (begin
+      (persist/append-batch
+        b
+        "s"
+        (list
+          (list "a" 0 {})
+          (list "b" 0 {})
+          (list "c" 0 {})))
+      (persist/count b "s")))
+  3)
+(persist-test
+  "batch continues an existing stream"
+  (let
+    ((b (persist/open)))
+    (begin
+      (persist/append b "s" "x" 0 {})
+      (let
+        ((evs (persist/append-batch b "s" (list (list "a" 0 {}) (list "b" 0 {})))))
+        (persist/event-seq (first evs)))))
+  2)
+(persist-test
+  "empty batch is a no-op"
+  (let
+    ((b (persist/open)))
+    (begin (persist/append-batch b "s" (list)) (persist/count b "s")))
+  0)
+(persist-test
+  "batch-expect with correct seq commits all"
+  (let
+    ((b (persist/open)))
+    (begin
+      (persist/append-batch-expect
+        b
+        "s"
+        0
+        (list
+          (list "a" 0 {})
+          (list "b" 0 {})))
+      (persist/count b "s")))
+  2)
+(persist-test
+  "batch-expect with stale seq writes nothing"
+  (let
+    ((b (persist/open)))
+    (begin
+      (persist/append b "s" "x" 0 {})
+      (persist/append-batch-expect
+        b
+        "s"
+        0
+        (list
+          (list "a" 0 {})
+          (list "b" 0 {})))
+      (persist/count b "s")))
+  1)
+(persist-test
+  "batch-expect stale returns a conflict"
+  (let
+    ((b (persist/open)))
+    (begin
+      (persist/append b "s" "x" 0 {})
+      (persist/conflict?
+        (persist/append-batch-expect
+          b
+          "s"
+          0
+          (list (list "a" 0 {}))))))
+  true)
+(persist-test
+  "batch data is preserved"
+  (let
+    ((b (persist/open)))
+    (begin
+      (persist/append-batch
+        b
+        "order"
+        (list
+          (list "placed" 0 {:id 1})
+          (list "line" 0 {:sku "x"})))
+      (get
+        (persist/event-data (nth (persist/read b "order") 1))
+        :sku)))
+  "x")
+(persist-test
+  "batch works on the durable backend"
+  (let
+    ((db (persist/mock-durable (persist/mem-backend))))
+    (begin
+      (persist/append-batch
+        db
+        "s"
+        (list
+          (list "a" 0 {})
+          (list "b" 0 {})))
+      (persist/last-seq db "s")))
+  2)