Merge pull request #50 from pimlicolabs/feat/get-required-prefund

Add util function get pre fund

.changeset/red-years-begin.md

@@ -0,0 +1,5 @@
+---
+"permissionless": patch
+---
+
+Added getRequiredPrefund utility function

src/accounts/signerToSafeSmartAccount.ts

@@ -62,7 +62,7 @@ const SAFE_VERSION_TO_ADDRESSES_MAP: {
 } = {
     "1.4.1": {
         ADD_MODULES_LIB_ADDRESS: "0x8EcD4ec46D4D2a6B64fE960B3D64e8B94B2234eb",
-        SAFE_4337_MODULE_ADDRESS: "0x39E54Bb2b3Aa444b4B39DEe15De3b7809c36Fc38",
+        SAFE_4337_MODULE_ADDRESS: "0xa581c4A4DB7175302464fF3C06380BC3270b4037",
         SAFE_PROXY_FACTORY_ADDRESS:
             "0x4e1DCf7AD4e460CfD30791CCC4F9c8a4f820ec67",
         SAFE_SINGLETON_ADDRESS: "0x41675C099F32341bf84BFc5382aF534df5C7461a",

src/utils/getRequiredPrefund.ts

@@ -0,0 +1,31 @@
+import type { UserOperation } from "../types"
+
+export type GetRequiredPrefundReturnType = {
+    userOperation: UserOperation
+}
+
+/**
+ *
+ * Returns the minimum required funds in the senders's smart account to execute the user operation.
+ *
+ * @param arags: {userOperation} as {@link UserOperation}
+ * @returns requiredPrefund as {@link bigint}
+ *
+ * @example
+ * import { getRequiredPrefund } from "permissionless/utils"
+ *
+ * const requiredPrefund = getRequiredPrefund({
+ *     userOperation
+ * })
+ */
+export const getRequiredPrefund = ({
+    userOperation
+}: GetRequiredPrefundReturnType): bigint => {
+    const multiplier = userOperation.paymasterAndData.length > 2 ? 3n : 1n
+    const requiredGas =
+        userOperation.callGasLimit +
+        userOperation.verificationGasLimit * multiplier +
+        userOperation.preVerificationGas
+
+    return BigInt(requiredGas) * BigInt(userOperation.maxFeePerGas)
+}

src/utils/index.ts

@@ -1,4 +1,8 @@
 import type { Account, Address } from "viem"
+import {
+    type GetRequiredPrefundReturnType,
+    getRequiredPrefund
+} from "./getRequiredPrefund.js"
 import {
     type GetUserOperationHashParams,
     getUserOperationHash
@@ -16,6 +20,8 @@ export function parseAccount(account: Address | Account): Account {
 
 export {
     getUserOperationHash,
+    getRequiredPrefund,
+    type GetRequiredPrefundReturnType,
     type GetUserOperationHashParams,
     signUserOperationHashWithECDSA,
     AccountOrClientNotFoundError

test/index.test.ts

@@ -1,7 +1,10 @@
 import { beforeAll, describe, expect, test } from "bun:test"
 import dotenv from "dotenv"
 import { getSenderAddress, getUserOperationHash } from "permissionless"
-import { signUserOperationHashWithECDSA } from "permissionless/utils"
+import {
+    getRequiredPrefund,
+    signUserOperationHashWithECDSA
+} from "permissionless/utils"
 import { buildUserOp, getAccountInitCode } from "./userOp.js"
 import {
     getBundlerClient,
@@ -163,4 +166,30 @@ describe("test public actions and utils", () => {
 
         expect(signature).toEqual(userOperation.signature)
     })
+
+    test("getRequiredGas", async () => {
+        const bundlerClient = getBundlerClient()
+        const eoaWalletClient = getEoaWalletClient()
+        const userOperation = await buildUserOp(eoaWalletClient)
+
+        const gasParameters = await bundlerClient.estimateUserOperationGas({
+            userOperation,
+            entryPoint: getEntryPoint()
+        })
+
+        userOperation.callGasLimit = gasParameters.callGasLimit
+        userOperation.verificationGasLimit = gasParameters.verificationGasLimit
+        userOperation.preVerificationGas = gasParameters.preVerificationGas
+
+        const requiredGas = getRequiredPrefund({
+            userOperation
+        })
+
+        expect(requiredGas).toBe(
+            (gasParameters.callGasLimit +
+                gasParameters.verificationGasLimit +
+                gasParameters.preVerificationGas) *
+                userOperation.maxFeePerGas
+        )
+    })
 })