fix(amm): Prevent creation of constant product AMM with non-fungible central token

packages/run-protocol/src/vpool-xyk-amm/multipoolMarketMaker.js

@@ -7,6 +7,7 @@ import { AssetKind, makeIssuerKit } from '@agoric/ertp';
 import { CONTRACT_ELECTORATE, handleParamGovernance } from '@agoric/governance';
 
 import { assertIssuerKeywords } from '@agoric/zoe/src/contractSupport/index.js';
+import { E } from '@endo/far';
 import { makeAddPool } from './pool.js';
 import { makeMakeAddLiquidityInvitation } from './addLiquidity.js';
 import { makeMakeRemoveLiquidityInvitation } from './removeLiquidity.js';
@@ -17,8 +18,7 @@ import { makeMakeSwapInvitation } from './swap.js';
 import { makeDoublePool } from './doublePool.js';
 import { makeParamManager, POOL_FEE_KEY, PROTOCOL_FEE_KEY } from './params.js';
 
-const { details: X } = assert;
-
+const { quote: q, details: X } = assert;
 /**
  * Multipool AMM is a rewrite of Uniswap that supports multiple liquidity pools,
  * and direct exchanges across pools. Please see the documentation for more:
@@ -115,14 +115,27 @@ const start = async (zcf, privateArgs) => {
   } = /** @type { Terms & AMMTerms } */ (zcf.getTerms());
   assertIssuerKeywords(zcf, ['Central']);
   assert(centralBrand !== undefined, X`centralBrand must be present`);
+
   const { initialPoserInvitation } = privateArgs;
 
-  const paramManager = await makeParamManager(
-    zcf.getZoeService(),
-    poolFeeParam.value,
-    protocolFeeParam.value,
-    initialPoserInvitation,
+  const [paramManager, centralDisplayInfo] = await Promise.all([
+    makeParamManager(
+      zcf.getZoeService(),
+      poolFeeParam.value,
+      protocolFeeParam.value,
+      initialPoserInvitation,
+    ),
+    E(centralBrand).getDisplayInfo(),
+  ]);
+
+  assert.equal(
+    centralDisplayInfo.assetKind,
+    AssetKind.NAT,
+    X`Central must be of kind ${q(AssetKind.NAT)}, not ${q(
+      centralDisplayInfo.assetKind,
+    )}`,
   );
+
   const { wrapPublicFacet, wrapCreatorFacet, getNat, getInvitationAmount } =
     handleParamGovernance(zcf, paramManager);
 

packages/run-protocol/test/amm/vpool-xyk-amm/test-xyk-amm-swap.js

@@ -3,7 +3,7 @@
 // eslint-disable-next-line import/no-extraneous-dependencies
 import { test } from '@agoric/zoe/tools/prepare-test-env-ava.js';
 
-import { makeIssuerKit, AmountMath } from '@agoric/ertp';
+import { makeIssuerKit, AmountMath, AssetKind } from '@agoric/ertp';
 import { E } from '@agoric/eventual-send';
 
 import {
@@ -29,6 +29,23 @@ import { setupAmmServices } from './setup.js';
 const { quote: q } = assert;
 const { ceilDivide } = natSafeMath;
 
+test('amm with non-fungible central token', async t => {
+  // Set up central token
+  const centralR = makeIssuerKit('central', AssetKind.SET);
+  const electorateTerms = { committeeName: 'EnBancPanel', committeeSize: 3 };
+  const timer = buildManualTimer(console.log, 30n);
+
+  await t.throwsAsync(
+    () => setupAmmServices(electorateTerms, centralR, timer),
+    {
+      message: `Central must be of kind ${q(AssetKind.NAT)}, not ${q(
+        AssetKind.SET,
+      )}`,
+    },
+    'test AssetKind.SET as central brand',
+  );
+});
+
 test('amm with valid offers', async t => {
   // Set up central token
   const centralR = makeIssuerKit('central');