Add Account framework (#5657)

test/helpers/erc4337.js

@@ -1,4 +1,4 @@
-const { ethers } = require('hardhat');
+const { ethers, config, entrypoint, senderCreator } = require('hardhat');
 
 const SIG_VALIDATION_SUCCESS = '0x0000000000000000000000000000000000000000';
 const SIG_VALIDATION_FAILURE = '0x0000000000000000000000000000000000000001';
@@ -83,6 +83,129 @@ class UserOperation {
   }
 }
 
+const parseInitCode = initCode => ({
+  factory: '0x' + initCode.replace(/0x/, '').slice(0, 40),
+  factoryData: '0x' + initCode.replace(/0x/, '').slice(40),
+});
+
+/// Global ERC-4337 environment helper.
+class ERC4337Helper {
+  constructor() {
+    this.factoryAsPromise = ethers.deployContract('$Create2');
+  }
+
+  async wait() {
+    this.factory = await this.factoryAsPromise;
+    return this;
+  }
+
+  async newAccount(name, extraArgs = [], params = {}) {
+    const env = {
+      entrypoint: params.entrypoint ?? entrypoint.v08,
+      senderCreator: params.senderCreator ?? senderCreator.v08,
+    };
+
+    const { factory } = await this.wait();
+
+    const accountFactory = await ethers.getContractFactory(name);
+
+    if (params.erc7702signer) {
+      const delegate = await accountFactory.deploy(...extraArgs);
+      const instance = await params.erc7702signer.getAddress().then(address => accountFactory.attach(address));
+      const authorization = await params.erc7702signer.authorize({ address: delegate.target });
+      return new ERC7702SmartAccount(instance, authorization, env);
+    } else {
+      const initCode = await accountFactory
+        .getDeployTransaction(...extraArgs)
+        .then(tx =>
+          factory.interface.encodeFunctionData('$deploy', [0, params.salt ?? ethers.randomBytes(32), tx.data]),
+        )
+        .then(deployCode => ethers.concat([factory.target, deployCode]));
+
+      const instance = await ethers.provider
+        .call({
+          from: env.entrypoint,
+          to: env.senderCreator,
+          data: env.senderCreator.interface.encodeFunctionData('createSender', [initCode]),
+        })
+        .then(result => ethers.getAddress(ethers.hexlify(ethers.getBytes(result).slice(-20))))
+        .then(address => accountFactory.attach(address));
+
+      return new SmartAccount(instance, initCode, env);
+    }
+  }
+}
+
+/// Represent one ERC-4337 account contract.
+class SmartAccount extends ethers.BaseContract {
+  constructor(instance, initCode, env) {
+    super(instance.target, instance.interface, instance.runner, instance.deployTx);
+    this.address = instance.target;
+    this.initCode = initCode;
+    this._env = env;
+  }
+
+  async deploy(account = this.runner) {
+    const { factory: to, factoryData: data } = parseInitCode(this.initCode);
+    this.deployTx = await account.sendTransaction({ to, data });
+    return this;
+  }
+
+  async createUserOp(userOp = {}) {
+    userOp.sender ??= this;
+    userOp.nonce ??= await this._env.entrypoint.getNonce(userOp.sender, 0);
+    if (ethers.isAddressable(userOp.paymaster)) {
+      userOp.paymaster = await ethers.resolveAddress(userOp.paymaster);
+      userOp.paymasterVerificationGasLimit ??= 100_000n;
+      userOp.paymasterPostOpGasLimit ??= 100_000n;
+    }
+    return new UserOperationWithContext(userOp, this._env);
+  }
+}
+
+class ERC7702SmartAccount extends SmartAccount {
+  constructor(instance, authorization, env) {
+    super(instance, undefined, env);
+    this.authorization = authorization;
+  }
+
+  async deploy() {
+    // hardhat signers from @nomicfoundation/hardhat-ethers do not support type 4 txs.
+    // so we rebuild it using "native" ethers
+    await ethers.Wallet.fromPhrase(config.networks.hardhat.accounts.mnemonic, ethers.provider).sendTransaction({
+      to: ethers.ZeroAddress,
+      authorizationList: [this.authorization],
+      gasLimit: 46_000n, // 21,000 base + PER_EMPTY_ACCOUNT_COST
+    });
+
+    return this;
+  }
+}
+
+class UserOperationWithContext extends UserOperation {
+  constructor(userOp, env) {
+    super(userOp);
+    this._sender = userOp.sender;
+    this._env = env;
+  }
+
+  addInitCode() {
+    if (this._sender?.initCode) {
+      return Object.assign(this, parseInitCode(this._sender.initCode));
+    } else throw new Error('No init code available for the sender of this user operation');
+  }
+
+  getAuthorization() {
+    if (this._sender?.authorization) {
+      return this._sender.authorization;
+    } else throw new Error('No EIP-7702 authorization available for the sender of this user operation');
+  }
+
+  hash() {
+    return super.hash(this._env.entrypoint);
+  }
+}
+
 module.exports = {
   SIG_VALIDATION_SUCCESS,
   SIG_VALIDATION_FAILURE,
@@ -90,4 +213,5 @@ module.exports = {
   packInitCode,
   packPaymasterAndData,
   UserOperation,
+  ERC4337Helper,
 };