From 8c0a9a40835d6e9d78fe812ed3f26605ee7b866b Mon Sep 17 00:00:00 2001
From: Michael FIG <mfig@agoric.com>
Date: Wed, 24 May 2023 19:44:26 -0600
Subject: [PATCH 1/2] test(xsnap): check trivial snapshot golden hashes

---
 .../xsnap/test/snapshots/test-xsnap.js.md     |  15 ++++++
 .../xsnap/test/snapshots/test-xsnap.js.snap   | Bin 0 -> 318 bytes
 packages/xsnap/test/test-xsnap.js             |  50 ++++++++++++++++++
 3 files changed, 65 insertions(+)
 create mode 100644 packages/xsnap/test/snapshots/test-xsnap.js.md
 create mode 100644 packages/xsnap/test/snapshots/test-xsnap.js.snap

diff --git a/packages/xsnap/test/snapshots/test-xsnap.js.md b/packages/xsnap/test/snapshots/test-xsnap.js.md
new file mode 100644
index 00000000000..eec90719b35
--- /dev/null
+++ b/packages/xsnap/test/snapshots/test-xsnap.js.md
@@ -0,0 +1,15 @@
+# Snapshot report for `test/test-xsnap.js`
+
+The actual snapshot is saved in `test-xsnap.js.snap`.
+
+Generated by [AVA](https://avajs.dev).
+
+## produce golden snapshot hashes
+
+> no evaluations
+
+    '91d30e59c1a087d58bb6d8eefcf1262e99e59cfc249222ab25f881ac642437e5'
+
+> smallish safeInteger multiplication doesn't spill to XS_NUMBER_KIND
+
+    '4b48f6c58c08bb757efd3b8fb21891a386bdc5bfbae6803c8cb7df108e553ace'
diff --git a/packages/xsnap/test/snapshots/test-xsnap.js.snap b/packages/xsnap/test/snapshots/test-xsnap.js.snap
new file mode 100644
index 0000000000000000000000000000000000000000..c4e93b1b54a770305f26642187162713e2c3522c
GIT binary patch
literal 318
zcmV-E0m1%3RzV<BZeeh9Xm4~Nb~6eC08lR59b2qjTwy{oCSYTliI+7FHdgfh8*5)o
zR`A$Qb03Qc00000000AR&b>~<FcbygRtPck0>~R{?8M2<hWHsOL<SI2x9a-(y0LKW
zsCH3TcoX`hP*69{c65gCd^r;mz2%Ps7heMJucmFXJ7Td;!EzKi;*`f!#E5z1>`y&^
z9<0TJ%i(NxF*{~{KD(UX^wQQ9>z*W5&{++}v=*2hIjLI3eSaJssis#-p;6iaNTjw=
zP2I8PfQCbiN$@*{9TuNr{-0`01Fj_vRQ)KO?%3JdfHO)$FR_N!SklHB<QA%$fJ|qd
ztbnzyk@%0=-{lR4;PWUlI$p%WYu<{@E)+inPrna@O`PL(5qa_<h?2zeWi`A$-99|8
Q9v8#?HzL1v7DoX900qR7HUIzs

literal 0
HcmV?d00001

diff --git a/packages/xsnap/test/test-xsnap.js b/packages/xsnap/test/test-xsnap.js
index 1947ef26b63..b5f70fab5ec 100644
--- a/packages/xsnap/test/test-xsnap.js
+++ b/packages/xsnap/test/test-xsnap.js
@@ -4,6 +4,7 @@ import '@endo/init/debug.js';
 // eslint-disable-next-line import/no-extraneous-dependencies
 import test from 'ava';
 
+import { createHash } from 'crypto';
 import * as proc from 'child_process';
 import * as os from 'os';
 import fs from 'fs';
@@ -302,6 +303,55 @@ const writeAndReadSnapshot = async (t, snapshotUseFs) => {
 test('write and read snapshot (use FS)', writeAndReadSnapshot, true);
 test('write and read snapshot (use stream)', writeAndReadSnapshot, false);
 
+test('produce golden snapshot hashes', async t => {
+  t.log(`\
+The snapshot hashes produced by this test were created from this package's
+version of xsnap compiled for and run on Agoric's supported (within-consensus)
+platforms.
+
+The snapshot will change (and the test will fail) if xsnap or this platform
+is not compatible with this predefined consensus.  This is likely to happen
+in the future when xsnap is upgraded, in which case there will need to be
+special accommodation for the new version, not just generating new golden
+hashes.
+`);
+  const toEvals = [
+    [`no evaluations`, ''],
+    [
+      `smallish safeInteger multiplication doesn't spill to XS_NUMBER_KIND`,
+      `globalThis.bazinga = 100; globalThis.bazinga *= 1_000_000;`,
+    ],
+  ];
+  for await (const [description, toEval] of toEvals) {
+    t.log(description);
+    const messages = [];
+    async function handleCommand(message) {
+      messages.push(decode(message));
+      return new Uint8Array();
+    }
+
+    const vat0 = await xsnap({
+      ...options(io),
+      handleCommand,
+      snapshotUseFs: false,
+    });
+    if (toEval) {
+      await vat0.evaluate(toEval);
+    }
+
+    const hash = createHash('sha256');
+    for await (const buf of vat0.makeSnapshotStream()) {
+      hash.update(buf);
+    }
+    await vat0.close();
+
+    const hexHash = hash.digest('hex');
+    t.log(`${description} produces golden hash ${hexHash}`);
+    t.snapshot(hexHash, description);
+    t.deepEqual(messages, [], `${description} messages`);
+  }
+});
+
 test('execute immediately after makeSnapshotStream', async t => {
   const messages = [];
   async function handleCommand(message) {

From a2b48e1793e4a95e10a47a3650278e24e20e974a Mon Sep 17 00:00:00 2001
From: Michael FIG <mfig@agoric.com>
Date: Wed, 24 May 2023 19:50:31 -0600
Subject: [PATCH 2/2] build(xsnap): use `-D__has_builtin(x)=1` to avoid
 divergence

---
 packages/xsnap/src/build.js | 1 +
 1 file changed, 1 insertion(+)

diff --git a/packages/xsnap/src/build.js b/packages/xsnap/src/build.js
index db1c060dd11..b2b95361581 100644
--- a/packages/xsnap/src/build.js
+++ b/packages/xsnap/src/build.js
@@ -230,6 +230,7 @@ async function main(args, { env, stdout, spawn, fs, os }) {
         `MODDABLE=${ModdableSDK.MODDABLE}`,
         `GOAL=${goal}`,
         `XSNAP_VERSION=${pkg.version}`,
+        `CC=cc "-D__has_builtin(x)=1"`,
         '-f',
         'xsnap-worker.mk',
       ],