feat(evm-wallet-experiment): Use object capability sheaves

packages/evm-wallet-experiment/src/lib/delegation-twin.test.ts

@@ -1,3 +1,9 @@
+import {
+  matches,
+  getInterfaceGuardPayload,
+  getMethodGuardPayload,
+} from '@endo/patterns';
+import type { InterfaceGuard, MethodGuard, Pattern } from '@endo/patterns';
 import { describe, expect, it, vi } from 'vitest';
 
 import type {
@@ -122,11 +128,11 @@ describe('makeDelegationTwin', () => {
   });
 
   describe('transferFungible twin', () => {
-    it('normalizes checksummed token address to lowercase in section.token', () => {
+    it('normalizes checksummed token address to lowercase in transferFungible guard', () => {
       const CHECKSUMMED_TOKEN =
         '0xAaAaAaAaAaAaAaAaAaAaAaAaAaAaAaAaAaAaAaAa' as Address;
       const redeemFn = vi.fn().mockResolvedValue(TX_HASH);
-      const section = makeDelegationTwin({
+      makeDelegationTwin({
         grant: {
           method: 'transferFungible',
           token: CHECKSUMMED_TOKEN,
@@ -135,7 +141,18 @@ describe('makeDelegationTwin', () => {
         },
         redeemFn,
       });
-      expect(section.token).toBe(CHECKSUMMED_TOKEN.toLowerCase());
+      // The guard's first arg for transferFungible is M.eq(token.toLowerCase()).
+      // If the token is not normalized here, incoming calls with the canonical
+      // lowercase address would be rejected by the guard at dispatch time.
+      const ifacePayload = getInterfaceGuardPayload(
+        lastInterfaceGuard as InterfaceGuard,
+      ) as unknown as { methodGuards: Record<string, MethodGuard> };
+      const methodPayload = getMethodGuardPayload(
+        ifacePayload.methodGuards.transferFungible,
+      ) as unknown as { argGuards: Pattern[] };
+      const tokenGuard = methodPayload.argGuards[0];
+      expect(matches(CHECKSUMMED_TOKEN.toLowerCase(), tokenGuard)).toBe(true);
+      expect(matches(CHECKSUMMED_TOKEN, tokenGuard)).toBe(false);
     });
 
     it('exposes transferFungible method', () => {

packages/evm-wallet-experiment/src/lib/delegation-twin.ts

@@ -1,32 +1,32 @@
 import { M } from '@endo/patterns';
 import { makeDiscoverableExo } from '@metamask/kernel-utils/discoverable';
+import { constant } from '@metamask/kernel-utils/sheaf';
+import type { PresheafSection } from '@metamask/kernel-utils/sheaf';
 
 import { encodeTransfer } from './erc20.ts';
 import { METHOD_CATALOG } from './method-catalog.ts';
 import type { Address, DelegationGrant, Execution, Hex } from '../types.ts';
 
-export type DelegationSection =
-  | { exo: object; method: 'transferNative' }
-  | { exo: object; method: 'transferFungible'; token: Address };
+type AwayMetadata = { mode: string; delegationId?: string };
 
 type DelegationTwinOptions = {
   grant: DelegationGrant;
   redeemFn: (execution: Execution) => Promise<Hex>;
 };
 
 /**
- * Build a DelegationSection for a delegation grant.
+ * Build a PresheafSection for a delegation grant.
  * The resulting exo exposes the method covered by the grant, enforcing
  * local guards and (for transferFungible) a local budget tracker.
  *
  * @param options - Twin construction options.
  * @param options.grant - The semantic delegation grant to wrap.
  * @param options.redeemFn - Submits an Execution to the delegation framework.
- * @returns A DelegationSection wrapping the delegation exo.
+ * @returns A PresheafSection with constant delegation metadata.
  */
 export function makeDelegationTwin(
   options: DelegationTwinOptions,
-): DelegationSection {
+): PresheafSection<AwayMetadata> {
   const { grant, redeemFn } = options;
   const { delegation } = grant;
   const idPrefix = delegation.id.slice(0, 12);
@@ -90,7 +90,10 @@ export function makeDelegationTwin(
       interfaceGuard,
     );
 
-    return { exo, method: 'transferNative' };
+    return {
+      exo,
+      metadata: constant({ mode: 'delegation', delegationId: delegation.id }),
+    };
   }
 
   // transferFungible — normalize token address to lowercase for consistent matching.
@@ -152,5 +155,8 @@ export function makeDelegationTwin(
     interfaceGuard,
   );
 
-  return { exo, method: 'transferFungible', token };
+  return {
+    exo,
+    metadata: constant({ mode: 'delegation', delegationId: delegation.id }),
+  };
 }