From 9d57c661957b840bfee2a40e8f820b8795baed52 Mon Sep 17 00:00:00 2001
From: Brian Warner <warner@lothar.com>
Date: Fri, 12 May 2023 12:16:12 -0700
Subject: [PATCH] chore: switch to E.when for promise-space onResolve hook

This is more defensive against sneaky promises, at the cost of
delaying storage by a turn for non-promises.
---
 packages/vats/package.json               | 1 +
 packages/vats/src/core/promise-space.js  | 9 +++------
 packages/vats/test/test-promise-space.js | 1 +
 3 files changed, 5 insertions(+), 6 deletions(-)

diff --git a/packages/vats/package.json b/packages/vats/package.json
index 0b919d89bc3b..feba8668e786 100644
--- a/packages/vats/package.json
+++ b/packages/vats/package.json
@@ -42,6 +42,7 @@
     "@agoric/vat-data": "^0.4.3",
     "@agoric/zoe": "^0.25.3",
     "@agoric/zone": "^0.1.0",
+    "@endo/eventual-send": "^0.17.2",
     "@endo/far": "^0.2.18",
     "@endo/import-bundle": "^0.3.4",
     "@endo/init": "^0.5.56",
diff --git a/packages/vats/src/core/promise-space.js b/packages/vats/src/core/promise-space.js
index 9abbd92e0bec..6de261874fa9 100644
--- a/packages/vats/src/core/promise-space.js
+++ b/packages/vats/src/core/promise-space.js
@@ -1,7 +1,8 @@
 // @ts-check
+import { E } from '@endo/eventual-send';
 import { assertKey } from '@agoric/store';
 import { canBeDurable } from '@agoric/vat-data';
-import { isPromise, makePromiseKit } from '@endo/promise-kit';
+import { makePromiseKit } from '@endo/promise-kit';
 
 /**
  * @typedef {{
@@ -59,11 +60,7 @@ export const makeStoreHooks = (store, log = noop) => {
   return harden({
     ...logHooks,
     onResolve: (name, valueP) => {
-      if (isPromise(valueP)) {
-        void valueP.then(value => save(name, value));
-      } else {
-        save(name, valueP);
-      }
+      void E.when(valueP, value => save(name, value));
     },
     onReset: name => {
       if (store.has(name)) {
diff --git a/packages/vats/test/test-promise-space.js b/packages/vats/test/test-promise-space.js
index 0bdb4539b430..38b7fda8fa8b 100644
--- a/packages/vats/test/test-promise-space.js
+++ b/packages/vats/test/test-promise-space.js
@@ -64,6 +64,7 @@ test('makePromiseSpace copied into store', async t => {
     produce.chocolate.resolve(doesNotResolve);
     const nonPassable = harden(() => {});
     produce.strawberry.resolve(nonPassable);
+    await null;
     const actual = Object.fromEntries(store.entries());
     t.deepEqual(
       actual,