release:v1.3.1

Author: JairusSW

CHANGELOG.md

@@ -1,6 +1,6 @@
 # Changelog
 
-## 2026-03-25 - 1.3.1
+## Unreleased
 
 - feat: allow `JSON.Value` to store and re-serialize built-in typed arrays and `ArrayBuffer`
 - feat: support `JSON.stringify<ArrayBuffer>(...)` directly without a dedicated helper
@@ -17,7 +17,9 @@
 - fix: rewrite nested `JSON.parse(...)` calls inside custom serializers and deserializers to `JSON.internal.parse(...)`, matching the existing internal stringify rewrite and documented behavior
 - docs: clarify that custom serializers and deserializers must always produce and consume valid JSON
 - docs: document how subclassing built-in container types behaves, including when `@json` custom overrides take effect
+- fix: stop naive string deserialization scratch allocations from growing across repeated large payload parses by using local `ensureSize(...)` scratch capacity instead of serialization-style proposed growth
 - tests: expand custom serializer/deserializer coverage for nullable fields, multiple custom fields, escaped content, whitespace, and repeated round-trips
+- tests: add a repeated large string-heavy struct parse regression that exercises the naive deserialization scratch path
 - tests: add override coverage for plain and custom subclasses of `Array`, `Map`, `Set`, and typed arrays
 - tests: add `JSON.Value` regressions for undecorated and decorated typed-array subclasses
 - tests: add regression coverage for generated `@json` subclasses inheriting stdlib typed-array fields

assembly/__tests__/struct.spec.ts

@@ -196,3 +196,39 @@ describe("Extended regression coverage - nested and escaped payloads", () => {
   expect(JSON.stringify(JSON.parse<i32[][]>("[[1],[2,3],[]]"))).toBe("[[1],[2,3],[]]");
   expect(JSON.stringify(JSON.parse<string>('"line\\nbreak"'))).toBe('"line\\nbreak"');
 });
+
+describe("Should keep naive string scratch space bounded across repeated large struct parses", () => {
+  const payload = buildStringHeavyPayload();
+
+  for (let i = 0; i < 256; i++) {
+    const parsed = JSON.parse<StringHeavyPayload>(payload);
+    expect(parsed.title.length).toBe(704);
+    expect(parsed.repo.length).toBe(608);
+    expect(parsed.summary.length).toBe(704);
+    expect(parsed.footer.length).toBe(384);
+  }
+});
+
+function repeatChunk(chunk: string, count: i32): string {
+  let out = "";
+  for (let i = 0; i < count; i++) out += chunk;
+  return out;
+}
+
+function buildStringHeavyPayload(): string {
+  const title = repeatChunk("alpha-beta-", 64);
+  const repo = repeatChunk("octocat/repository/", 32);
+  const summary = repeatChunk("payload-segment-", 44);
+  const footer = repeatChunk("final-block-", 32);
+
+  return '{"title":"' + title + '","repo":"' + repo + '","summary":"' + summary + '","footer":"' + footer + '"}';
+}
+
+
+@json
+class StringHeavyPayload {
+  title: string = "";
+  repo: string = "";
+  summary: string = "";
+  footer: string = "";
+}

assembly/deserialize/simple/string.ts

@@ -31,7 +31,7 @@ import { hex4_to_u16_swar } from "../../util/swar";
   srcStart += 2;
   srcEnd -= 2;
   const outStart = bs.offset - bs.buffer;
-  bs.proposeSize(u32(srcEnd - srcStart));
+  bs.ensureSize(u32(srcEnd - srcStart));
 
   while (srcStart < srcEnd) {
     const block = load<u16>(srcStart);