From 43b87ed442e55d4e053b252504ae8ebd981e8d16 Mon Sep 17 00:00:00 2001
From: Peter Steinberger <steipete@gmail.com>
Date: Mon, 5 Oct 2026 11:29:00 -0700
Subject: [PATCH] test(vm): check retained growth after warming script caches

Adapt the live-cell and batched-collection approach from oven-sh/bun#42474 while preserving 10000 scripts in every profile and the original 200/700 MiB RSS bounds. Compare the second half against an identical warmup workload so allocator and code-cache startup do not masquerade as retained growth.
---
 .github/OPENCLAW_CI.md              |  6 ++++
 CHANGELOG.md                        |  2 ++
 test/js/node/vm/script-leak.test.ts | 43 +++++++++++++++++------------
 3 files changed, 34 insertions(+), 17 deletions(-)

diff --git a/.github/OPENCLAW_CI.md b/.github/OPENCLAW_CI.md
index 43741a63cf84..412d25e8fbf2 100644
--- a/.github/OPENCLAW_CI.md
+++ b/.github/OPENCLAW_CI.md
@@ -84,6 +84,12 @@ test/js/node/process/process.test.js
 test/js/bun/sqlite/column-types.test.js
 ```
 
+The `vm.Script` leak regression checks live `Script` cells after collection and
+collects between allocation batches. It measures RSS growth over the second half
+of the workload, after warming the code cache and allocator with the first half. It retains the 200 MiB release and 700 MiB ASAN limits; a deliberately
+retained-script control must fail the live-cell assertion when qualifying changes
+to this guard.
+
 ## Caches and artifacts
 
 The lane caches the build system's download/prebuilt/ccache directory, Rust
diff --git a/CHANGELOG.md b/CHANGELOG.md
index f3e73f501a42..9b134fb7197f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -203,3 +203,5 @@
 - Add position-preserving `module.stripTypeScriptTypes()` strip mode for tooling that analyzes TypeScript exports. Adapts [oven-sh/bun#35517](https://github.com/oven-sh/bun/pull/35517); thanks @cirospaciari!
 
 - Keep query and fragment imports of compiled embedded modules on their canonical module record, including Windows and non-ASCII filenames.
+
+- Check live `vm.Script` counts and post-warmup RSS growth in the leak regression, preserving the 200 MiB release and 700 MiB ASAN RSS limits. Adapts [oven-sh/bun#42474](https://github.com/oven-sh/bun/pull/42474); thanks @robobun!
diff --git a/test/js/node/vm/script-leak.test.ts b/test/js/node/vm/script-leak.test.ts
index 586ec3d88b99..2c9161997b64 100644
--- a/test/js/node/vm/script-leak.test.ts
+++ b/test/js/node/vm/script-leak.test.ts
@@ -1,30 +1,39 @@
-const vm = require("vm");
-const { describe, it, expect } = require("bun:test");
-const { isASAN, rss } = require("harness");
+import { heapStats } from "bun:jsc";
+import { describe, expect, it } from "bun:test";
+import { isASAN, rss } from "harness";
+import vm from "node:vm";
+
+const iterations = 10_000;
+const batch = 500;
 
 describe("vm.Script", () => {
   it("shouldn't leak memory", () => {
-    const initialUsage = rss();
-
-    {
-      const source = `/*\n${Buffer.alloc(10000, " * aaaaa\n").toString("utf8")}\n*/ Buffer.alloc(10, 'hello');`;
-
-      function go(i) {
-        const script = new vm.Script(source + "//" + i);
-        script.runInThisContext();
-      }
+    Bun.gc(true);
+    const initialCount = heapStats().objectTypeCounts.Script ?? 0;
+    let initialUsage = 0;
+    const source = `/*\n${Buffer.alloc(50_000, " * aaaaa\n").toString("utf8")}\n*/ Buffer.alloc(10, 'hello').toString();`;
 
-      for (let i = 0; i < 10000; ++i) {
-        go(i);
-      }
+    let result;
+    function go(i) {
+      const script = new vm.Script(source + "//" + i);
+      result = script.runInThisContext();
     }
 
+    for (let i = 0; i < iterations; ++i) {
+      go(i);
+      // Bound temporary garbage before it inflates the allocator's resident pages.
+      if ((i + 1) % batch === 0) Bun.gc(true);
+      // Measure growth after warming the code cache and allocator with the same work.
+      if (i + 1 === iterations / 2) initialUsage = rss();
+    }
+    expect(result).toBe("hellohello");
     Bun.gc(true);
 
     const finalUsage = rss();
+    const finalCount = heapStats().objectTypeCounts.Script ?? 0;
     const megabytes = Math.round(((finalUsage - initialUsage) / 1024 / 1024) * 100) / 100;
-    // ASAN's quarantine retains freed allocations (default 256 MB) so RSS
-    // deltas run far higher under bun-asan; widen the threshold there.
+    expect(finalCount).toBeLessThanOrEqual(initialCount + 10);
+    // ASAN's quarantine retains freed allocations (default 256 MB).
     expect(megabytes).toBeLessThan(isASAN ? 700 : 200);
   });
 });