chore: toSerializableTransaction function for gas estimation (#652)

* chore: toSerializableTransaction function for gas estimation

* chore: Refactor gas estimation in sendTransactionWorker

* Revert "chore: Refactor gas estimation in sendTransactionWorker"

This reverts commit 4b2170b.

* make it simpler

* chore: add getPopulatedTransactionOrErroredTransaction helper

* chore: log on estimate error

Author: d4mr

src/utils/transaction/userOperation.ts

@@ -5,6 +5,7 @@ import {
   getContract,
   prepareContractCall,
   readContract,
+  toSerializableTransaction,
 } from "thirdweb";
 import {
   UserOperation,
@@ -19,6 +20,7 @@ import { QueuedTransaction } from "./types";
 
 export const generateSignedUserOperation = async (
   queuedTransaction: QueuedTransaction,
+  populatedTransaction: Awaited<ReturnType<typeof toSerializableTransaction>>,
 ): Promise<UserOperation> => {
   const {
     chainId,
@@ -73,24 +75,15 @@ export const generateSignedUserOperation = async (
     address: accountFactoryAddress as Address,
   });
 
-  let toAddress: string | undefined;
-  let txValue: bigint | undefined;
-  let txData: Hex | undefined;
-
-  // Handle UserOp Requests
-  if (data && target) {
-    toAddress = target;
-    txValue = value || 0n;
-    txData = data;
-  } else {
-    throw new Error("Invalid UserOperation parameters");
-  }
-
   // Prepare UserOperation Call
   const userOpCall = prepareContractCall({
     contract: smartAccountContract,
     method: "function execute(address, uint256, bytes)",
-    params: [toAddress || "", txValue || 0n, txData || "0x"],
+    params: [
+      populatedTransaction.to || "",
+      populatedTransaction.value || 0n,
+      populatedTransaction.data,
+    ],
   });
 
   // Create Unsigned UserOperation

src/worker/tasks/sendTransactionWorker.ts

@@ -120,7 +120,22 @@ const _sendUserOp = async (
   assert(queuedTransaction.isUserOp);
 
   const chain = await getChain(queuedTransaction.chainId);
-  const signedUserOp = await generateSignedUserOperation(queuedTransaction);
+
+  const [populatedTransaction, erroredTransaction] =
+    await getPopulatedOrErroredTransaction(queuedTransaction);
+
+  if (erroredTransaction) {
+    job.log(
+      `Failed to validate transaction: ${erroredTransaction.errorMessage}`,
+    );
+    return erroredTransaction;
+  }
+
+  const signedUserOp = await generateSignedUserOperation(
+    queuedTransaction,
+    populatedTransaction,
+  );
+
   const userOpHash = await bundleUserOp({
     userOp: signedUserOp,
     options: {
@@ -150,34 +165,17 @@ const _sendTransaction = async (
   assert(!queuedTransaction.isUserOp);
 
   const { queueId, chainId, from } = queuedTransaction;
-  const chain = await getChain(chainId);
-
   // Populate the transaction to resolve gas values.
   // This call throws if the execution would be reverted.
   // The nonce is _not_ set yet.
-  let populatedTransaction: Awaited<
-    ReturnType<typeof toSerializableTransaction>
-  >;
-  try {
-    populatedTransaction = await toSerializableTransaction({
-      from: getChecksumAddress(from),
-      transaction: {
-        client: thirdwebClient,
-        chain,
-        ...queuedTransaction,
-        // Stub the nonce because it will be overridden later.
-        nonce: 1,
-      },
-    });
-  } catch (e: unknown) {
-    // If the transaction will revert, error.message contains the human-readable error.
-    const errorMessage = (e as Error)?.message ?? `${e}`;
-    job.log(`Failed to estimate gas: ${errorMessage}`);
-    return {
-      ...queuedTransaction,
-      status: "errored",
-      errorMessage,
-    };
+  const [populatedTransaction, erroredTransaction] =
+    await getPopulatedOrErroredTransaction(queuedTransaction);
+
+  if (erroredTransaction) {
+    job.log(
+      `Failed to validate transaction: ${erroredTransaction.errorMessage}`,
+    );
+    return erroredTransaction;
   }
 
   // Acquire an unused nonce for this transaction.
@@ -393,3 +391,39 @@ export const initSendTransactionWorker = () => {
     }
   });
 };
+
+export const getPopulatedOrErroredTransaction = async (
+  queuedTransaction: QueuedTransaction,
+): Promise<
+  | [Awaited<ReturnType<typeof toSerializableTransaction>>, undefined]
+  | [undefined, ErroredTransaction]
+> => {
+  try {
+    const from = queuedTransaction.isUserOp
+      ? queuedTransaction.accountAddress
+      : queuedTransaction.from;
+
+    if (!from) throw new Error("Invalid transaction parameters: from");
+
+    const populatedTransaction = await toSerializableTransaction({
+      from: getChecksumAddress(from),
+      transaction: {
+        client: thirdwebClient,
+        chain: await getChain(queuedTransaction.chainId),
+        ...queuedTransaction,
+        // if transaction is EOA, we stub the nonce to reduce RPC calls
+        nonce: queuedTransaction.isUserOp ? undefined : 1,
+      },
+    });
+
+    return [populatedTransaction, undefined];
+  } catch (e: unknown) {
+    const erroredTransaction: ErroredTransaction = {
+      ...queuedTransaction,
+      status: "errored",
+      errorMessage: (e as Error)?.message ?? `${e}`,
+    };
+
+    return [undefined, erroredTransaction];
+  }
+};