Remove gasleft in setupModules, add erc4337 compatibility test

.env.sample

@@ -4,3 +4,8 @@ INFURA_KEY=""
 # Used for custom network
 NODE_URL=""
 ETHERSCAN_API_KEY=""
+# (Optional) Used to run ERC-4337 compatibility test. MNEMONIC is also required.
+ERC4337_TEST_BUNDLER_URL=
+ERC4337_TEST_NODE_URL=
+ERC4337_TEST_SINGLETON_ADDRESS=
+ERC4337_TEST_SAFE_FACTORY_ADDRESS=

README.md

@@ -15,13 +15,31 @@ Usage
 yarn
 ```
 
-### Run all tests:
+### Testing
+
+To run the tests:
 
 ```bash
 yarn build
 yarn test
 ```
 
+Optionally, if you want to run the ERC-4337 compatibility test, it uses a live bundler and node, so it contains some pre-requisites:
+
+1. Define the environment variables:
+
+```
+ERC4337_TEST_BUNDLER_URL=
+ERC4337_TEST_NODE_URL=
+ERC4337_TEST_SINGLETON_ADDRESS=
+ERC4337_TEST_SAFE_FACTORY_ADDRESS=
+MNEMONIC=
+```
+
+2. Pre-fund the executor account derived from the mnemonic with some Native Token to cover the deployment of an ERC4337 module and the pre-fund of the Safe for the test operation.
+
+3. If necessary, edit the hardcoded base fee in `contracts/test/4337/UserOperation.sol`
+
 ### Deployments
 
 A collection of the different Safe contract deployments and their addresses can be found in the [Safe deployments](https://github.com/safe-global/safe-deployments) repository.

contracts/base/ModuleManager.sol

@@ -35,7 +35,7 @@ abstract contract ModuleManager is SelfAuthorized, Executor {
         if (to != address(0)) {
             require(isContract(to), "GS002");
             // Setup has to complete successfully or transaction fails.
-            require(execute(to, 0, data, Enum.Operation.DelegateCall, gasleft()), "GS000");
+            require(execute(to, 0, data, Enum.Operation.DelegateCall, type(uint256).max), "GS000");
         }
     }
 

contracts/test/4337/Test4337ModuleAndHandler.sol

@@ -0,0 +1,69 @@
+// SPDX-License-Identifier: LGPL-3.0-only
+pragma solidity >=0.7.0 <0.9.0;
+pragma abicoder v2;
+
+import "../../libraries/SafeStorage.sol";
+import "./UserOperation.sol";
+
+interface ISafe {
+    function execTransactionFromModule(address to, uint256 value, bytes memory data, uint8 operation) external returns (bool success);
+}
+
+/// @dev A Dummy 4337 Module/Handler for testing purposes
+/// @dev DO NOT USE IN PRODUCTION
+contract Test4337ModuleAndHandler is SafeStorage {
+    using UserOperationLib for UserOperation;
+
+    address public immutable myAddress;
+    address public immutable entryPoint;
+
+    address internal constant SENTINEL_MODULES = address(0x1);
+
+    constructor(address entryPointAddress) {
+        entryPoint = entryPointAddress;
+        myAddress = address(this);
+    }
+
+    function validateUserOp(UserOperation calldata userOp, bytes32, uint256 missingAccountFunds) external returns (uint256 validationData) {
+        address payable safeAddress = payable(userOp.sender);
+        ISafe senderSafe = ISafe(safeAddress);
+
+        if (missingAccountFunds != 0) {
+            ISafe(senderSafe).execTransactionFromModule(entryPoint, missingAccountFunds, "", 0);
+        }
+
+        return 0;
+    }
+
+    function execTransaction(address to, uint256 value, bytes calldata data) external payable {
+        // we need to strip out msg.sender address appended by HandlerContext contract from the calldata
+        bytes memory callData;
+        // solhint-disable-next-line no-inline-assembly
+        assembly {
+            // Load free memory location
+            let pointer := mload(0x40)
+            // We allocate memory for the return data by setting the free memory location to
+            // current free memory location + data size + 32 bytes for data size value - 32 bytes for stripped msg.sender
+            mstore(0x40, add(pointer, calldatasize()))
+            // Store the size
+            mstore(pointer, sub(calldatasize(), 20))
+            // Store the data
+            calldatacopy(add(pointer, 0x20), 0, sub(calldatasize(), 20))
+            // Point the callData to the correct memory location
+            callData := pointer
+        }
+
+        address payable safeAddress = payable(msg.sender);
+        ISafe safe = ISafe(safeAddress);
+        require(safe.execTransactionFromModule(to, value, data, 0), "tx failed");
+    }
+
+    function enableMyself() public {
+        require(myAddress != address(this), "You need to DELEGATECALL, sir");
+
+        // Module cannot be added twice.
+        require(modules[myAddress] == address(0), "GS102");
+        modules[myAddress] = modules[SENTINEL_MODULES];
+        modules[SENTINEL_MODULES] = myAddress;
+    }
+}

contracts/test/4337/UserOperation.sol

@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity >=0.7.0 <0.9.0;
+
+/* solhint-disable no-inline-assembly */
+
+/**
+ * User Operation struct
+ * @param sender the sender account of this request.
+ * @param nonce unique value the sender uses to verify it is not a replay.
+ * @param initCode if set, the account contract will be created by this constructor/
+ * @param callData the method call to execute on this account.
+ * @param callGasLimit the gas limit passed to the callData method call.
+ * @param verificationGasLimit gas used for validateUserOp and validatePaymasterUserOp.
+ * @param preVerificationGas gas not calculated by the handleOps method, but added to the gas paid. Covers batch overhead.
+ * @param maxFeePerGas same as EIP-1559 gas parameter.
+ * @param maxPriorityFeePerGas same as EIP-1559 gas parameter.
+ * @param paymasterAndData if set, this field holds the paymaster address and paymaster-specific data. the paymaster will pay for the transaction instead of the sender.
+ * @param signature sender-verified signature over the entire request, the EntryPoint address and the chain ID.
+ */
+struct UserOperation {
+    address sender;
+    uint256 nonce;
+    bytes initCode;
+    bytes callData;
+    uint256 callGasLimit;
+    uint256 verificationGasLimit;
+    uint256 preVerificationGas;
+    uint256 maxFeePerGas;
+    uint256 maxPriorityFeePerGas;
+    bytes paymasterAndData;
+    bytes signature;
+}
+
+/**
+ * Utility functions helpful when working with UserOperation structs.
+ */
+library UserOperationLib {
+    function getSender(UserOperation calldata userOp) internal pure returns (address) {
+        address data;
+        //read sender from userOp, which is first userOp member (saves 800 gas...)
+        assembly {
+            data := calldataload(userOp)
+        }
+        return address(uint160(data));
+    }
+
+    // Solidity 0.7.6 doesn't support the BASEFEE opcode, so we hardcode it here.
+    function getBaseFee() public pure returns (uint256) {
+        return 20 gwei;
+    }
+
+    // relayer/block builder might submit the TX with higher priorityFee, but the user should not
+    // pay above what he signed for.
+    function gasPrice(UserOperation calldata userOp) internal pure returns (uint256) {
+        uint256 maxFeePerGas = userOp.maxFeePerGas;
+        uint256 maxPriorityFeePerGas = userOp.maxPriorityFeePerGas;
+        if (maxFeePerGas == maxPriorityFeePerGas) {
+            //legacy mode (for networks that don't support basefee opcode)
+            return maxFeePerGas;
+        }
+        return min(maxFeePerGas, maxPriorityFeePerGas + getBaseFee());
+    }
+
+    function calldataKeccak(bytes calldata data) public pure returns (bytes32 ret) {
+        assembly {
+            let mem := mload(0x40)
+            let len := data.length
+            calldatacopy(mem, data.offset, len)
+            ret := keccak256(mem, len)
+        }
+    }
+
+    function pack(UserOperation calldata userOp) internal pure returns (bytes memory ret) {
+        address sender = getSender(userOp);
+        uint256 nonce = userOp.nonce;
+        bytes32 hashInitCode = calldataKeccak(userOp.initCode);
+        bytes32 hashCallData = calldataKeccak(userOp.callData);
+        uint256 callGasLimit = userOp.callGasLimit;
+        uint256 verificationGasLimit = userOp.verificationGasLimit;
+        uint256 preVerificationGas = userOp.preVerificationGas;
+        uint256 maxFeePerGas = userOp.maxFeePerGas;
+        uint256 maxPriorityFeePerGas = userOp.maxPriorityFeePerGas;
+        bytes32 hashPaymasterAndData = calldataKeccak(userOp.paymasterAndData);
+
+        return
+            abi.encode(
+                sender,
+                nonce,
+                hashInitCode,
+                hashCallData,
+                callGasLimit,
+                verificationGasLimit,
+                preVerificationGas,
+                maxFeePerGas,
+                maxPriorityFeePerGas,
+                hashPaymasterAndData
+            );
+    }
+
+    function hash(UserOperation calldata userOp) internal pure returns (bytes32) {
+        return keccak256(pack(userOp));
+    }
+
+    function min(uint256 a, uint256 b) internal pure returns (uint256) {
+        return a < b ? a : b;
+    }
+}

hardhat.config.ts

@@ -1,3 +1,4 @@
+import "@nomiclabs/hardhat-ethers";
 import type { HardhatUserConfig, HttpNetworkUserConfig } from "hardhat/types";
 import "@nomiclabs/hardhat-etherscan";
 import "@nomiclabs/hardhat-waffle";

test/integration/Safe.ERC4337.spec.ts

@@ -0,0 +1,133 @@
+import hre from "hardhat";
+import { expect } from "chai";
+import { AddressZero } from "@ethersproject/constants";
+import { hexConcat } from "ethers/lib/utils";
+import { getFactoryContract, getSafeSingletonContract } from "../utils/setup";
+import { calculateProxyAddress } from "../../src/utils/proxies";
+
+const ERC4337_TEST_ENV_VARIABLES_DEFINED =
+    typeof process.env.ERC4337_TEST_BUNDLER_URL !== "undefined" &&
+    typeof process.env.ERC4337_TEST_NODE_URL !== "undefined" &&
+    typeof process.env.ERC4337_TEST_SAFE_FACTORY_ADDRESS !== "undefined" &&
+    typeof process.env.ERC4337_TEST_SINGLETON_ADDRESS !== "undefined" &&
+    typeof process.env.MNEMONIC !== "undefined";
+
+const itif = ERC4337_TEST_ENV_VARIABLES_DEFINED ? it : it.skip;
+const SAFE_FACTORY_ADDRESS = process.env.ERC4337_TEST_SAFE_FACTORY_ADDRESS;
+const SINGLETON_ADDRESS = process.env.ERC4337_TEST_SINGLETON_ADDRESS;
+const BUNDLER_URL = process.env.ERC4337_TEST_BUNDLER_URL;
+const NODE_URL = process.env.ERC4337_TEST_NODE_URL;
+const MNEMONIC = process.env.MNEMONIC;
+
+type UserOperation = {
+    sender: string;
+    nonce: string;
+    initCode: string;
+    callData: string;
+    callGasLimit: string;
+    verificationGasLimit: string;
+    preVerificationGas: string;
+    maxFeePerGas: string;
+    maxPriorityFeePerGas: string;
+    paymasterAndData: string;
+    signature: string;
+};
+
+const sleep = (ms: number) => new Promise((resolve) => setTimeout(resolve, ms));
+
+describe("Safe.ERC4337", () => {
+    const setupTests = async () => {
+        const factory = await getFactoryContract();
+        const singleton = await getSafeSingletonContract();
+        const bundlerProvider = new hre.ethers.providers.JsonRpcProvider(BUNDLER_URL);
+        const provider = new hre.ethers.providers.JsonRpcProvider(NODE_URL);
+        const userWallet = hre.ethers.Wallet.fromMnemonic(MNEMONIC as string).connect(provider);
+
+        const entryPoints = await bundlerProvider.send("eth_supportedEntryPoints", []);
+        if (entryPoints.length === 0) {
+            throw new Error("No entry points found");
+        }
+
+        return {
+            factory: factory.attach(SAFE_FACTORY_ADDRESS).connect(userWallet),
+            singleton: singleton.attach(SINGLETON_ADDRESS).connect(provider),
+            bundlerProvider,
+            provider,
+            userWallet,
+            entryPoints,
+        };
+    };
+
+    /**
+     * This test verifies the ERC4337 based on gas estimation for a user operation
+     * The user operation deploys a Safe with the ERC4337 module and a handler
+     * and executes a transaction, thus verifying two things:
+     * 1. Deployment of the Safe with the ERC4337 module and handler is possible
+     * 2. Executing a transaction is possible
+     */
+    itif("should pass the ERC4337 validation", async () => {
+        const { singleton, factory, provider, bundlerProvider, userWallet, entryPoints } = await setupTests();
+        const ENTRYPOINT_ADDRESS = entryPoints[0];
+
+        const erc4337ModuleAndHandlerFactory = (await hre.ethers.getContractFactory("Test4337ModuleAndHandler")).connect(userWallet);
+        const erc4337ModuleAndHandler = await erc4337ModuleAndHandlerFactory.deploy(ENTRYPOINT_ADDRESS);
+        // The bundler uses a different node, so we need to allow it sometime to sync
+        await sleep(10000);
+
+        const feeData = await provider.getFeeData();
+        const maxFeePerGas = feeData.maxFeePerGas.toHexString();
+
+        const maxPriorityFeePerGas = feeData.maxPriorityFeePerGas.toHexString();
+
+        const moduleInitializer = erc4337ModuleAndHandler.interface.encodeFunctionData("enableMyself", []);
+        const encodedInitializer = singleton.interface.encodeFunctionData("setup", [
+            [userWallet.address],
+            1,
+            erc4337ModuleAndHandler.address,
+            moduleInitializer,
+            erc4337ModuleAndHandler.address,
+            AddressZero,
+            0,
+            AddressZero,
+        ]);
+        const deployedAddress = await calculateProxyAddress(factory, singleton.address, encodedInitializer, 73);
+
+        // The initCode contains 20 bytes of the factory address and the rest is the calldata to be forwarded
+        const initCode = hexConcat([
+            factory.address,
+            factory.interface.encodeFunctionData("createProxyWithNonce", [singleton.address, encodedInitializer, 73]),
+        ]);
+        const userOpCallData = erc4337ModuleAndHandler.interface.encodeFunctionData("execTransaction", [userWallet.address, 0, 0]);
+
+        // Native tokens for the pre-fund 💸
+        await userWallet.sendTransaction({ to: deployedAddress, value: hre.ethers.utils.parseEther("0.001") });
+        // The bundler uses a different node, so we need to allow it sometime to sync
+        await sleep(10000);
+
+        const userOperation: UserOperation = {
+            sender: deployedAddress,
+            nonce: "0x0",
+            initCode,
+            callData: userOpCallData,
+            callGasLimit: "0x7A120",
+            verificationGasLimit: "0x7A120",
+            preVerificationGas: "0x186A0",
+            maxFeePerGas,
+            maxPriorityFeePerGas,
+            paymasterAndData: "0x",
+            signature: "0x",
+        };
+
+        const DEBUG_MESSAGE = `
+            Using entry point: ${ENTRYPOINT_ADDRESS}
+            Deployed Safe address: ${deployedAddress}
+            Module/Handler address: ${erc4337ModuleAndHandler.address}
+            User operation: 
+            ${JSON.stringify(userOperation, null, 2)}
+        `;
+        console.log(DEBUG_MESSAGE);
+
+        const estimatedGas = await bundlerProvider.send("eth_estimateUserOperationGas", [userOperation, ENTRYPOINT_ADDRESS]);
+        expect(estimatedGas).to.not.be.undefined;
+    });
+});

test/utils/setup.ts

@@ -28,6 +28,18 @@ export const getSafeSingleton = async () => {
     return Safe.attach(SafeDeployment.address);
 };
 
+export const getSafeSingletonContract = async () => {
+    const safeSingleton = await hre.ethers.getContractFactory(safeContractUnderTest());
+
+    return safeSingleton;
+};
+
+export const getFactoryContract = async () => {
+    const factory = await hre.ethers.getContractFactory("SafeProxyFactory");
+
+    return factory;
+};
+
 export const getFactory = async () => {
     const FactoryDeployment = await deployments.get("SafeProxyFactory");
     const Factory = await hre.ethers.getContractFactory("SafeProxyFactory");

tsconfig.json

@@ -18,5 +18,6 @@
       "resolveJsonModule": true
     },
     "exclude": ["dist", "node_modules"],
-    "include": ["./src/index.ts", "./types"]
+    "include": ["./src/index.ts", "./types"],
+    "files": ["./hardhat.config.ts"]
   }