From 6bbd799e32e30f6c0b4776564dc6ec5a326fb6a5 Mon Sep 17 00:00:00 2001
From: Michael FIG <mfig@agoric.com>
Date: Tue, 10 Dec 2024 17:09:18 -0600
Subject: [PATCH] fixup! feat(vats): first cut of Address Hooks in JS

---
 packages/cosmic-proto/src/address-hooks.js    | 38 ++++++++++++++-----
 .../cosmic-proto/test/address-hooks.test.js   | 30 ++++++++++++++-
 2 files changed, 57 insertions(+), 11 deletions(-)

diff --git a/packages/cosmic-proto/src/address-hooks.js b/packages/cosmic-proto/src/address-hooks.js
index 86c4d130f3a..073f0783c71 100644
--- a/packages/cosmic-proto/src/address-hooks.js
+++ b/packages/cosmic-proto/src/address-hooks.js
@@ -47,16 +47,23 @@ const ADDRESS_HOOK_MAGIC = new Uint8Array([
   0x70 | ADDRESS_HOOK_VERSION,
 ]);
 
-// The default maximum number of characters in a bech32-encoded hooked address.
+/**
+ * The default maximum number of characters in a bech32-encoded hooked address.
+ */
 export const DEFAULT_HOOKED_ADDRESS_CHAR_LIMIT = 1024;
 
 /**
- * @typedef {Record<string, string | (string | null)[] | null>} HookQuery
+ * @typedef {Record<string, string | (string | null)[] | null>} HookQuery A
+ * record of query keys mapped to query values.  `null` values denote valueless
+ * keys.  Array values denote multiple occurrences of a key:
+ *
+ *      { key: null } // '?key'
+ *      { key: 'value' } // '?key=value'
+ *      { key: ['value1', 'value2', 'value3'] } // '?key=value1&key=value2&key=value3'
+ *      { key: ['value1', null, 'value3'] } // '?key=value1&key&key=value3'
  */
 
 export const BASE_ADDRESS_LENGTH_BYTES = 2;
-export const MAX_BASE_ADDRESS_LENGTH =
-  (1 << (BASE_ADDRESS_LENGTH_BYTES * 8 - 1)) + 1;
 
 /**
  * @param {string} specimen
@@ -119,22 +126,33 @@ export const joinHookedAddress = (
   const { prefix, bytes } = decodeBech32(baseAddress, charLimit);
 
   const baseAddressLength = bytes.length;
-  if (baseAddressLength > MAX_BASE_ADDRESS_LENGTH) {
+  const b = baseAddressLength;
+  const hd = hookData.length;
+
+  const maxBaseAddressLength = 2 ** (BASE_ADDRESS_LENGTH_BYTES * 8);
+  if (b >= maxBaseAddressLength) {
     throw RangeError(
-      `Base address length 0x${baseAddressLength.toString(16)} exceeds maximum 0x${MAX_BASE_ADDRESS_LENGTH.toString(16)}`,
+      `Base address length 0x${b.toString(16)} exceeds maximum 0x${maxBaseAddressLength.toString(16)}`,
     );
   }
-  const b = baseAddressLength;
+
+  if (!Number.isSafeInteger(hd) || hd < 0) {
+    throw RangeError(`Hook data length ${hd} is not a non-negative integer`);
+  }
 
   const magicLength = ADDRESS_HOOK_MAGIC.length;
   const hookBuf = new Uint8Array(
-    magicLength + bytes.length + hookData.length + BASE_ADDRESS_LENGTH_BYTES,
+    magicLength + b + hd + BASE_ADDRESS_LENGTH_BYTES,
   );
-  hookBuf.set(ADDRESS_HOOK_MAGIC);
+  hookBuf.set(ADDRESS_HOOK_MAGIC, 0);
   hookBuf.set(bytes, magicLength);
   hookBuf.set(hookData, magicLength + b);
 
-  // Append the big-endian address length.
+  // Append the address length bytes, since we've already ensured these do not
+  // exceed maxBaseAddressLength above.  These are big-endian because the length
+  // is at the end of the payload, so if we want to support more bytes for the
+  // length, we just need encroach further into the payload.  We can do that
+  // without changing the meaning of the bytes at the end of existing payloads.
   let len = b;
   for (let i = 0; i < BASE_ADDRESS_LENGTH_BYTES; i += 1) {
     hookBuf[hookBuf.length - 1 - i] = len & 0xff;
diff --git a/packages/cosmic-proto/test/address-hooks.test.js b/packages/cosmic-proto/test/address-hooks.test.js
index 4dcea332637..31ce2334f10 100644
--- a/packages/cosmic-proto/test/address-hooks.test.js
+++ b/packages/cosmic-proto/test/address-hooks.test.js
@@ -3,6 +3,10 @@ import rawTest from '@endo/ses-ava/prepare-endo.js';
 import bundleSourceAmbient from '@endo/bundle-source';
 import { importBundle } from '@endo/import-bundle';
 
+import { createRequire } from 'node:module';
+
+const require = createRequire(import.meta.url);
+
 /**
  * @type {import('ava').TestFn<{
  *   addressHooks: import('../src/address-hooks.js');
@@ -11,9 +15,11 @@ import { importBundle } from '@endo/import-bundle';
 const test = rawTest;
 
 const makeTestContext = async () => {
+  // Do all this work so that we test bundling and evaluation of the module in a
+  // fresh compartment.
   const bundleSource = bundleSourceAmbient;
   const loadBundle = async specifier => {
-    const modulePath = new URL(specifier, import.meta.url).pathname;
+    const modulePath = require.resolve(specifier);
     const bundle = await bundleSource(modulePath);
     return bundle;
   };
@@ -212,3 +218,25 @@ test(
   },
   'cosmos10rchqqplv3ehg0tpyej8xapavgnxgum5843jvetkv4e8jargd9hxwqqp4vx73n',
 );
+
+test(
+  'slideshow hook',
+  addressHookMacro,
+  'agoric1qqp0e5ys',
+  {
+    stake: 'TIA',
+    strat: 'compound',
+    holder: 'agoric1adjbkubiukd',
+  },
+  'agoric10rchqqpldphkcer9wg7kzem0wf5kxvtpv34xy6m4vf5h26myyeehgcttv574gj2pyeehgunpws7kxmmdwphh2mnyqqqsc2lz8v',
+);
+
+test(
+  'Fast USDC hook',
+  addressHookMacro,
+  'agoric16kv2g7snfc4q24vg3pjdlnnqgngtjpwtetd2h689nz09lcklvh5s8u37ek',
+  {
+    EUD: 'osmo183dejcnmkka5dzcu9xw6mywq0p2m5peks28men',
+  },
+  'agoric10rchp4vc53apxn32q42c3zryml8xq3xshyzuhjk6405wtxy7tl3d7e0f8az423padaek6me38qekget2vdhx66mtvy6kg7nrw5uhsaekd4uhwufswqex6dtsv44hxv3cd4jkuqpqvduyhf',
+);