test(contracts-rfq): gas bench for TokenZapV1 (#3406)

* test: add minimal mock for a vault contract

* test: gas bench for TokenZap

packages/contracts-rfq/test/mocks/SimpleVaultMock.sol

@@ -0,0 +1,15 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.20;
+
+import {VaultMock} from "./VaultMock.sol";
+
+// solhint-disable no-empty-blocks
+/// @notice Vault mock for testing purposes. DO NOT USE IN PRODUCTION.
+contract SimpleVaultMock is VaultMock {
+    /// @notice We include an empty "test" function so that this contract does not appear in the coverage report.
+    function testSimpleVaultMock() external {}
+
+    function deposit(address token, uint256 amount, address user) external payable {
+        _deposit(user, token, amount);
+    }
+}

packages/contracts-rfq/test/mocks/VaultManyArguments.sol

@@ -3,10 +3,14 @@ pragma solidity ^0.8.20;
 
 import {VaultMock} from "./VaultMock.sol";
 
+// solhint-disable no-empty-blocks
 /// @notice Vault mock for testing purposes. DO NOT USE IN PRODUCTION.
 contract VaultManyArguments is VaultMock {
     error VaultManyArguments__SomeError();
 
+    /// @notice We include an empty "test" function so that this contract does not appear in the coverage report.
+    function testSimpleVaultMock() external {}
+
     function deposit(
         address token,
         bytes memory encodedToken,

packages/contracts-rfq/test/zaps/TokenZapV1.GasBench.t.sol

@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: MIT
+pragma solidity 0.8.24;
+
+import {TokenZapV1} from "../../contracts/zaps/TokenZapV1.sol";
+
+import {SimpleVaultMock} from "../mocks/SimpleVaultMock.sol";
+import {MockERC20} from "../MockERC20.sol";
+
+import {Test} from "forge-std/Test.sol";
+
+// solhint-disable func-name-mixedcase, ordering
+contract TokenZapV1GasBenchmarkTest is Test {
+    uint256 internal constant AMOUNT = 0.1337 ether;
+
+    SimpleVaultMock internal vault;
+    TokenZapV1 internal tokenZap;
+    MockERC20 internal erc20;
+
+    address internal user;
+    address internal nativeGasToken = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
+
+    function setUp() public {
+        tokenZap = new TokenZapV1();
+        vault = new SimpleVaultMock();
+        erc20 = new MockERC20("TKN", 18);
+
+        user = makeAddr("user");
+
+        erc20.mint(address(this), AMOUNT);
+        deal(address(this), AMOUNT);
+        // To simulate an average case we assume that the Vault contract has already other deposited funds.
+        erc20.mint(address(vault), 1000 * AMOUNT);
+        deal(address(vault), 1000 * AMOUNT);
+        // We also assume that this is not the first tx through the Zap, so the infinite approval has already been set.
+        vm.prank(address(tokenZap));
+        erc20.approve(address(vault), type(uint256).max);
+    }
+
+    function getVaultPayload(address token, uint256 amount) public view returns (bytes memory) {
+        return abi.encodeCall(vault.deposit, (token, amount, user));
+    }
+
+    function getZapData(bytes memory originalPayload) public view returns (bytes memory) {
+        // Amount is the second argument of the deposit function.
+        return tokenZap.encodeZapData(address(vault), originalPayload, 4 + 32);
+    }
+
+    function test_deposit_erc20() public {
+        bytes memory depositPayload = getVaultPayload(address(erc20), AMOUNT);
+        bytes memory zapData = getZapData(depositPayload);
+        // Transfer tokens to the zap contract first.
+        erc20.transfer(address(tokenZap), AMOUNT);
+        tokenZap.zap(address(erc20), AMOUNT, zapData);
+        // Check that the vault registered the deposit.
+        assertEq(vault.balanceOf(user, address(erc20)), AMOUNT);
+    }
+
+    function test_deposit_native() public {
+        bytes memory depositPayload = getVaultPayload(nativeGasToken, AMOUNT);
+        bytes memory zapData = getZapData(depositPayload);
+        tokenZap.zap{value: AMOUNT}(nativeGasToken, AMOUNT, zapData);
+        // Check that the vault registered the deposit.
+        assertEq(vault.balanceOf(user, nativeGasToken), AMOUNT);
+    }
+}