feat: Surface human-readable delegated revert reasons (#245)

* Implement human-readable revert reasons for transaction and user operation errors

* Add human-readable revert reasons to changelog

* Implement human-readable revert reason decoding for delegated execution errors

* Implement viem error decoding in revert reason handler and add corresponding tests

* Enhance revert reason decoding with additional tests and improved error handling

* Refactor revert reason decoding to streamline error handling and improve code clarity

Author: mj-kiwi

packages/delegator-e2e/test/delegationManagement.test.ts

@@ -18,6 +18,7 @@ import {
 } from '@metamask/smart-accounts-kit/contracts';
 import {
   gasPrice,
+  transport,
   sponsoredBundlerClient,
   deploySmartAccount,
   deployCounter,
@@ -26,12 +27,17 @@ import {
   fundAddress,
 } from './utils/helpers';
 import { expectUserOperationToSucceed } from './utils/assertions';
-import { encodeFunctionData, parseEther } from 'viem';
-import { generatePrivateKey, privateKeyToAccount } from 'viem/accounts';
+import { createWalletClient, encodeFunctionData, parseEther } from 'viem';
+import {
+  generatePrivateKey,
+  privateKeyToAccount,
+  type PrivateKeyAccount,
+} from 'viem/accounts';
 import CounterMetadata from './utils/counter/metadata.json';
 
 let aliceSmartAccount: MetaMaskSmartAccount<Implementation.Hybrid>;
 let bobSmartAccount: MetaMaskSmartAccount<Implementation.Hybrid>;
+let bob: PrivateKeyAccount;
 let aliceCounter: CounterContract;
 
 /**
@@ -51,7 +57,7 @@ let aliceCounter: CounterContract;
 
 beforeEach(async () => {
   const alice = privateKeyToAccount(generatePrivateKey());
-  const bob = privateKeyToAccount(generatePrivateKey());
+  bob = privateKeyToAccount(generatePrivateKey());
 
   aliceSmartAccount = await toMetaMaskSmartAccount({
     client: publicClient,
@@ -244,6 +250,74 @@ test('delegation management lifecycle: create, disable, enable, and check status
   expect(finalCount).toEqual(2n);
 });
 
+test('can decode raw simulate and execute redeemDelegations errors', async () => {
+  await fundAddress(bob.address);
+
+  const bobWalletClient = createWalletClient({
+    account: bob,
+    transport,
+    chain: publicClient.chain,
+  });
+
+  const delegation = createDelegation({
+    to: bob.address,
+    from: aliceSmartAccount.address,
+    environment: aliceSmartAccount.environment,
+    scope: {
+      type: 'functionCall',
+      targets: [aliceCounter.address],
+      selectors: ['increment()'],
+    },
+  });
+
+  const signedDelegation = {
+    ...delegation,
+    signature: await aliceSmartAccount.signDelegation({ delegation }),
+  };
+
+  const execution = createExecution({
+    target: aliceCounter.address,
+    callData: encodeFunctionData({
+      abi: CounterMetadata.abi,
+      functionName: 'setCount',
+      args: [1n],
+    }),
+  });
+
+  const redeemParams = {
+    client: bobWalletClient,
+    delegationManagerAddress: aliceSmartAccount.environment.DelegationManager,
+    delegations: [[signedDelegation]],
+    modes: [ExecutionMode.SingleDefault],
+    executions: [[execution]],
+  };
+  const expectedError = 'AllowedMethodsEnforcer:method-not-allowed';
+
+  const simulateError = await DelegationManager.simulate
+    .redeemDelegations(redeemParams)
+    .then(
+      () => undefined,
+      (error: unknown) => error,
+    );
+
+  expect(simulateError).toBeDefined();
+  expect(
+    DelegationManager.decode.redeemDelegationsError(simulateError)?.message,
+  ).toBe(expectedError);
+
+  const executeError = await DelegationManager.execute
+    .redeemDelegations(redeemParams)
+    .then(
+      () => undefined,
+      (error: unknown) => error,
+    );
+
+  expect(executeError).toBeDefined();
+  expect(
+    DelegationManager.decode.redeemDelegationsError(executeError)?.message,
+  ).toBe(expectedError);
+});
+
 test('only delegator can disable their own delegation', async () => {
   // Create a delegation from Alice to Bob
   const delegation = createDelegation({

packages/smart-accounts-kit/CHANGELOG.md

@@ -11,6 +11,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - ERC-7715 `token-approval-revocation` permission type ([#226](https://github.com/MetaMask/smart-accounts-kit/pull/226), [#237](https://github.com/MetaMask/smart-accounts-kit/pull/237))
 - `CaveatBuilder` for `ApprovalRevocationEnforcer`, deployment address added to `SmartAccountsEnvironment` ([#226](https://github.com/metamask/smart-accounts-kit/pull/226), [#237](https://github.com/MetaMask/smart-accounts-kit/pull/237))
+- Helper for decoding revert reasons from delegated execution errors while preserving the original error output ([#245](https://github.com/MetaMask/smart-accounts-kit/pull/245))
 
 ### Changed
 

packages/smart-accounts-kit/src/DelegationFramework/DelegationManager/decode.ts

@@ -0,0 +1,3 @@
+import { decodeError as redeemDelegationsError } from './methods/redeemDelegations';
+
+export { redeemDelegationsError };

packages/smart-accounts-kit/src/DelegationFramework/DelegationManager/index.ts

@@ -1,7 +1,8 @@
 import * as constants from './constants';
+import * as decode from './decode';
 import * as encode from './encode';
 import * as execute from './execute';
 import * as read from './read';
 import * as simulate from './simulate';
 
-export { encode, execute, read, simulate, constants };
+export { decode, encode, execute, read, simulate, constants };

packages/smart-accounts-kit/src/DelegationFramework/DelegationManager/methods/redeemDelegations.ts

@@ -3,6 +3,10 @@ import type { Address, Client } from 'viem';
 import { encodeFunctionData } from 'viem';
 import { simulateContract, writeContract } from 'viem/actions';
 
+import {
+  decodeRevertReason,
+  type DecodedRevertReason,
+} from '../../../decodeRevertReason';
 import { encodeDelegations } from '../../../delegation';
 import { encodeExecutionCalldatas } from '../../../executions';
 import type { ExecutionMode, ExecutionStruct } from '../../../executions';
@@ -25,6 +29,10 @@ export type ExecuteRedeemDelegationsParameters = {
   delegationManagerAddress: Address;
 } & EncodeRedeemDelegationsParameters;
 
+export type DecodeRedeemDelegationsErrorReturnType =
+  | DecodedRevertReason
+  | undefined;
+
 export const simulate = async ({
   client,
   delegationManagerAddress,
@@ -77,3 +85,13 @@ export const encode = ({
     ],
   });
 };
+
+/**
+ * Decodes revert data from errors thrown by `simulate` or `execute`.
+ *
+ * @param error - The original error thrown by viem or an RPC provider.
+ * @returns A decoded revert reason, if one can be recognized.
+ */
+export const decodeError = (
+  error: unknown,
+): DecodeRedeemDelegationsErrorReturnType => decodeRevertReason(error);