feat: only send 1 meta transaction when sponsored [ID-1152] (#1080)

Author: yundifu

packages/passport/sdk/src/zkEvm/sendTransaction.test.ts

@@ -87,6 +87,55 @@ describe('sendTransaction', () => {
     );
   });
 
+  it('calls relayerClient.ethSendTransaction with sponsored meta transaction', async () => {
+    (retryWithDelay as jest.Mock).mockResolvedValue({
+      status: RelayerTransactionStatus.SUCCESSFUL,
+      hash: transactionHash,
+    } as RelayerTransaction);
+
+    const mockImxFeeOption = {
+      tokenPrice: '0',
+      tokenSymbol: 'IMX',
+      tokenDecimals: 18,
+      tokenAddress: '0x1337',
+      recipientAddress: '0x7331',
+    };
+
+    relayerClient.imGetFeeOptions.mockResolvedValue([mockImxFeeOption]);
+
+    const result = await sendTransaction({
+      params: [transactionRequest],
+      magicProvider,
+      jsonRpcProvider: jsonRpcProvider as JsonRpcProvider,
+      relayerClient: relayerClient as unknown as RelayerClient,
+      user: mockUserZkEvm,
+      guardianClient: guardianClient as unknown as GuardianClient,
+    });
+
+    expect(result).toEqual(transactionHash);
+    expect(guardianClient.validateEVMTransaction).toHaveBeenCalledWith(
+      {
+        chainId: chainIdEip155,
+        nonce,
+        user: mockUserZkEvm,
+        metaTransactions: [
+          {
+            data: transactionRequest.data,
+            revertOnError: true,
+            to: mockUserZkEvm.zkEvm.ethAddress,
+            value: '0x00',
+            nonce,
+          },
+        ],
+      },
+    );
+
+    expect(relayerClient.ethSendTransaction).toHaveBeenCalledWith(
+      mockUserZkEvm.zkEvm.ethAddress,
+      signedTransactions,
+    );
+  });
+
   it('calls guardian.evaluateTransaction with the correct arguments', async () => {
     (retryWithDelay as jest.Mock).mockResolvedValue({
       status: RelayerTransactionStatus.SUCCESSFUL,

packages/passport/sdk/src/zkEvm/sendTransaction.ts

@@ -1,7 +1,7 @@
 import {
-  ExternalProvider, JsonRpcProvider, TransactionRequest, Web3Provider,
+  ExternalProvider, JsonRpcProvider, JsonRpcSigner, TransactionRequest, Web3Provider,
 } from '@ethersproject/providers';
-import { BigNumber } from 'ethers';
+import { BigNumber, BigNumberish } from 'ethers';
 import { getEip155ChainId, getNonce, getSignedMetaTransactions } from './walletHelpers';
 import { MetaTransaction, RelayerTransactionStatus } from './types';
 import { JsonRpcError, RpcErrorCode } from './JsonRpcError';
@@ -22,6 +22,51 @@ export type EthSendTransactionParams = {
   params: Array<any>;
 };
 
+const getMetaTransactions = async (
+  metaTransaction: MetaTransaction,
+  nonce: BigNumberish,
+  chainId: BigNumber,
+  walletAddress: string,
+  signer: JsonRpcSigner,
+  relayerClient: RelayerClient,
+): Promise<MetaTransaction[]> => {
+  // NOTE: We sign the transaction before getting the fee options because
+  // accurate estimation of a transaction gas cost is only possible if the smart
+  // wallet contract can actually execute it (in a simulated environment) - and
+  // it can only execute signed transactions.
+  const signedTransaction = await getSignedMetaTransactions(
+    [metaTransaction],
+    nonce,
+    chainId,
+    walletAddress,
+    signer,
+  );
+
+  // TODO: ID-698 Add support for non-native gas payments (e.g ERC20, feeTransaction initialisation must change)
+
+  // NOTE: "Fee Options" represent the multiple ways we could pay for the gas
+  // used in this transaction. Each fee option has a "recipientAddress" we
+  // should transfer the payment to, an amount and a currency. We choose one
+  // option and build a transaction that sends the expected currency amount for
+  // that option to the specified address.
+  const feeOptions = await relayerClient.imGetFeeOptions(walletAddress, signedTransaction);
+  const imxFeeOption = feeOptions.find((feeOption) => feeOption.tokenSymbol === 'IMX');
+  if (!imxFeeOption) {
+    throw new Error('Failed to retrieve fees for IMX token');
+  }
+
+  const feeMetaTransaction: MetaTransaction = {
+    nonce,
+    to: imxFeeOption.recipientAddress,
+    value: imxFeeOption.tokenPrice,
+    revertOnError: true,
+  };
+  if (BigNumber.from(feeMetaTransaction.value).isZero()) {
+    return [metaTransaction];
+  }
+  return [metaTransaction, feeMetaTransaction];
+};
+
 export const sendTransaction = ({
   params,
   magicProvider,
@@ -50,49 +95,26 @@ export const sendTransaction = ({
       revertOnError: true,
     };
 
-    // NOTE: We sign the transaction before getting the fee options because
-    // accurate estimation of a transaction gas cost is only possible if the smart
-    // wallet contract can actually execute it (in a simulated environment) - and
-    // it can only execute signed transactions.
-    const signedTransaction = await getSignedMetaTransactions(
-      [metaTransaction],
+    const metaTransactions = await getMetaTransactions(
+      metaTransaction,
       nonce,
       chainIdBigNumber,
       user.zkEvm.ethAddress,
       signer,
+      relayerClient,
     );
 
-    // TODO: ID-698 Add support for non-native gas payments (e.g ERC20, feeTransaction initialisation must change)
-
-    // NOTE: "Fee Options" represent the multiple ways we could pay for the gas
-    // used in this transaction. Each fee option has a "recipientAddress" we
-    // should transfer the payment to, an amount and a currency. We choose one
-    // option and build a transaction that sends the expected currency amount for
-    // that option to the specified address.
-    const feeOptions = await relayerClient.imGetFeeOptions(user.zkEvm.ethAddress, signedTransaction);
-    const imxFeeOption = feeOptions.find((feeOption) => feeOption.tokenSymbol === 'IMX');
-    if (!imxFeeOption) {
-      throw new Error('Failed to retrieve fees for IMX token');
-    }
-
-    const feeMetaTransaction: MetaTransaction = {
-      nonce,
-      to: imxFeeOption.recipientAddress,
-      value: imxFeeOption.tokenPrice,
-      revertOnError: true,
-    };
-
     await guardianClient.validateEVMTransaction({
       chainId: getEip155ChainId(chainId),
       nonce: convertBigNumberishToString(nonce),
       user,
-      metaTransactions: [metaTransaction, feeMetaTransaction],
+      metaTransactions,
     });
 
     // NOTE: We sign again because we now are adding the fee transaction, so the
     // whole payload is different and needs a new signature.
     const signedTransactions = await getSignedMetaTransactions(
-      [metaTransaction, feeMetaTransaction],
+      metaTransactions,
       nonce,
       chainIdBigNumber,
       user.zkEvm.ethAddress,