Add EIP7702Utils (#5587)

test/account/utils/EIP7702Utils.test.js

@@ -0,0 +1,53 @@
+const { ethers, config } = require('hardhat');
+const { expect } = require('chai');
+const { loadFixture } = require('@nomicfoundation/hardhat-network-helpers');
+
+// [NOTE]
+//
+// ethers.getSigners() returns object than cannot currently send type-4 transaction, or sign authorization. Therefore,
+// we have to instantiate the eoa AND the relayer manually using ethers 6.14.0 wallets. This can be improved when
+// @nomicfoundation/hardhat-ethers starts instantiating signers with 7702 support.
+const relayAuthorization = authorization =>
+  ethers.Wallet.fromPhrase(config.networks.hardhat.accounts.mnemonic, ethers.provider).sendTransaction({
+    to: ethers.ZeroAddress,
+    authorizationList: [authorization],
+    gasLimit: 46_000n,
+  });
+
+const fixture = async () => {
+  const eoa = ethers.Wallet.createRandom(ethers.provider);
+  const mock = await ethers.deployContract('$EIP7702Utils');
+  return { eoa, mock };
+};
+
+describe('EIP7702Utils', function () {
+  beforeEach(async function () {
+    Object.assign(this, await loadFixture(fixture));
+  });
+
+  describe('fetchDelegate', function () {
+    it('EOA without delegation', async function () {
+      await expect(this.mock.$fetchDelegate(this.eoa)).to.eventually.equal(ethers.ZeroAddress);
+    });
+
+    it('EOA with delegation', async function () {
+      // set delegation
+      await this.eoa.authorize({ address: this.mock }).then(relayAuthorization);
+
+      await expect(this.mock.$fetchDelegate(this.eoa)).to.eventually.equal(this.mock);
+    });
+
+    it('EOA with revoked delegation', async function () {
+      // set delegation
+      await this.eoa.authorize({ address: this.mock }).then(relayAuthorization);
+      // reset delegation
+      await this.eoa.authorize({ address: ethers.ZeroAddress }).then(relayAuthorization);
+
+      await expect(this.mock.$fetchDelegate(this.eoa)).to.eventually.equal(ethers.ZeroAddress);
+    });
+
+    it('other smart contract', async function () {
+      await expect(this.mock.$fetchDelegate(this.mock)).to.eventually.equal(ethers.ZeroAddress);
+    });
+  });
+});