Merge pull request #25 from propeller-heads/router/dc/ENG-4041-swap

feat: Swap public method

foundry/interfaces/IExecutor.sol

@@ -22,6 +22,7 @@ interface IExecutor {
      */
     function swap(uint256 givenAmount, bytes calldata data)
         external
+        payable
         returns (uint256 calculatedAmount);
 }
 

foundry/lib/IWETH.sol

@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.28;
+
+import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
+
+interface IWETH is IERC20 {
+    function deposit() external payable;
+    function withdraw(uint256) external;
+}

foundry/lib/LibSwap.sol

@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.28;
+
+library LibSwap {
+    /// Returns the InToken index into an array of tokens
+    function tokenInIndex(bytes calldata swap)
+        internal
+        pure
+        returns (uint8 res)
+    {
+        res = uint8(swap[0]);
+    }
+
+    /// The OutToken index into an array of tokens
+    function tokenOutIndex(bytes calldata swap)
+        internal
+        pure
+        returns (uint8 res)
+    {
+        res = uint8(swap[1]);
+    }
+
+    /// The relative amount of token quantity routed into this swap
+    function splitPercentage(bytes calldata swap)
+        internal
+        pure
+        returns (uint24 res)
+    {
+        res = uint24(bytes3(swap[2:5]));
+    }
+
+    /// The address of the executor contract
+    function executor(bytes calldata swap)
+        internal
+        pure
+        returns (address res)
+    {
+        res = address(uint160(bytes20(swap[5:25])));
+    }
+
+    /// The selector to be used of the executor contract
+    function executorSelector(bytes calldata swap)
+        internal
+        pure
+        returns (bytes4 res)
+    {
+        res = bytes4(swap[25:29]);
+    }
+
+    /// Remaining bytes are interpreted as protocol data
+    function protocolData(bytes calldata swap)
+        internal
+        pure
+        returns (bytes calldata res)
+    {
+        res = swap[29:];
+    }
+}

foundry/src/CallbackVerificationDispatcher.sol

@@ -49,6 +49,7 @@ contract CallbackVerificationDispatcher {
     // slither-disable-next-line dead-code
     function _callVerifyCallback(bytes calldata data)
         internal
+        view
         returns (
             uint256 amountOwed,
             uint256 amountReceived,

foundry/src/ExecutionDispatcher.sol

@@ -50,29 +50,21 @@ contract ExecutionDispatcher {
      * @dev Calls an executor, assumes swap.protocolData contains
      *  protocol-specific data required by the executor.
      */
-    // slither-disable-next-line dead-code
+    // slither-disable-next-line delegatecall-loop
-    function _callExecutor(uint256 amount, bytes calldata data)
+    function _callExecutor(
-        internal
+        address executor,
-        returns (uint256 calculatedAmount)
+        bytes4 selector,
-    {
+        uint256 amount,
-        address executor;
+        bytes calldata data
-        bytes4 decodedSelector;
+    ) internal returns (uint256 calculatedAmount) {
-        bytes memory protocolData;
-
-        (executor, decodedSelector, protocolData) =
-            _decodeExecutorAndSelector(data);
-
         if (!executors[executor]) {
             revert ExecutionDispatcher__UnapprovedExecutor();
         }
 
-        bytes4 selector = decodedSelector == bytes4(0)
+        selector = selector == bytes4(0) ? IExecutor.swap.selector : selector;
-            ? IExecutor.swap.selector
+        // slither-disable-next-line controlled-delegatecall,low-level-calls
-            : decodedSelector;
-
-        // slither-disable-next-line low-level-calls
         (bool success, bytes memory result) = executor.delegatecall(
-            abi.encodeWithSelector(selector, amount, protocolData)
+            abi.encodeWithSelector(selector, amount, data)
         );
 
         if (!success) {
@@ -87,16 +79,4 @@ contract ExecutionDispatcher {
 
         calculatedAmount = abi.decode(result, (uint256));
     }
-
-    // slither-disable-next-line dead-code
-    function _decodeExecutorAndSelector(bytes calldata data)
-        internal
-        pure
-        returns (address executor, bytes4 selector, bytes memory protocolData)
-    {
-        require(data.length >= 24, "Invalid data length");
-        executor = address(uint160(bytes20(data[:20])));
-        selector = bytes4(data[20:24]);
-        protocolData = data[24:];
-    }
 }

foundry/src/TychoRouter.sol

@@ -1,26 +1,37 @@
 // SPDX-License-Identifier: UNLICENSED
 pragma solidity ^0.8.28;
 
+import "../lib/IWETH.sol";
+import "../lib/bytes/LibPrefixLengthEncodedByteArray.sol";
+import "./CallbackVerificationDispatcher.sol";
 import "@openzeppelin/contracts/access/AccessControl.sol";
 import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
 import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
+import "@openzeppelin/contracts/utils/ReentrancyGuard.sol";
+import "@openzeppelin/contracts/utils/Pausable.sol";
 import "@permit2/src/interfaces/IAllowanceTransfer.sol";
 import "./ExecutionDispatcher.sol";
 import "./CallbackVerificationDispatcher.sol";
-import "@openzeppelin/contracts/utils/Pausable.sol";
+import {LibSwap} from "../lib/LibSwap.sol";
 
 error TychoRouter__WithdrawalFailed();
 error TychoRouter__AddressZero();
+error TychoRouter__NegativeSlippage(uint256 amount, uint256 minAmount);
+error TychoRouter__MessageValueMismatch(uint256 value, uint256 amount);
 
 contract TychoRouter is
     AccessControl,
     ExecutionDispatcher,
     CallbackVerificationDispatcher,
-    Pausable
+    Pausable,
+    ReentrancyGuard
 {
     IAllowanceTransfer public immutable permit2;
+    IWETH private immutable _weth;
 
     using SafeERC20 for IERC20;
+    using LibPrefixLengthEncodedByteArray for bytes;
+    using LibSwap for bytes;
 
     //keccak256("NAME_OF_ROLE") : save gas on deployment
     bytes32 public constant EXECUTOR_SETTER_ROLE =
@@ -48,9 +59,10 @@ contract TychoRouter is
     );
     event FeeSet(uint256 indexed oldFee, uint256 indexed newFee);
 
-    constructor(address _permit2) {
+    constructor(address _permit2, address weth) {
         permit2 = IAllowanceTransfer(_permit2);
         _grantRole(DEFAULT_ADMIN_ROLE, msg.sender);
+        _weth = IWETH(weth);
     }
 
     /**
@@ -77,22 +89,116 @@ contract TychoRouter is
     }
 
     /**
-     * @dev Executes a swap graph supporting internal splits token amount
+     * @notice Executes a swap operation based on a predefined swap graph, supporting internal token amount splits.
-     *  splits, checking that the user gets more than minUserAmount of buyToken.
+     *         This function enables multi-step swaps, optional ETH wrapping/unwrapping, and validates the output amount
+     *         against a user-specified minimum.
+     *
+     * @dev
+     * - If `wrapEth` is true, the contract wraps the provided native ETH into WETH and uses it as the sell token.
+     * - If `unwrapEth` is true, the contract converts the resulting WETH back into native ETH before sending it to the receiver.
+     * - For ERC20 tokens, Permit2 is used to approve and transfer tokens from the caller to the router.
+     * - Swaps are executed sequentially using the `_splitSwap` function.
+     * - A fee is deducted from the output token if `fee > 0`, and the remaining amount is sent to the receiver.
+     * - Reverts with `TychoRouter__NegativeSlippage` if the output amount is less than `minAmountOut` and `minAmountOut` is bigger than 0.
+     *
+     * @param amountIn The input token amount to be swapped.
+     * @param tokenIn The address of the input token. Use `address(0)` for native ETH when `wrapEth` is true.
+     * @param tokenOut The address of the output token. Use `address(0)` for native ETH when `unwrapEth` is true.
+     * @param minAmountOut The minimum acceptable amount of the output token. Reverts if this condition is not met. If it's 0, no check is performed.
+     * @param wrapEth If true, treats the input token as native ETH and wraps it into WETH.
+     * @param unwrapEth If true, unwraps the resulting WETH into native ETH and sends it to the receiver.
+     * @param nTokens The total number of tokens involved in the swap graph (used to initialize arrays for internal calculations).
+     * @param receiver The address to receive the output tokens.
+     * @param permitSingle A Permit2 structure containing token approval details for the input token. Ignored if `wrapEth` is true.
+     * @param signature A valid signature authorizing the Permit2 approval. Ignored if `wrapEth` is true.
+     * @param swaps Encoded swap graph data containing details of each swap.
+     *
+     * @return amountOut The total amount of the output token received by the receiver, after deducting fees if applicable.
      */
     function swap(
         uint256 amountIn,
         address tokenIn,
-        uint256 minUserAmount,
+        address tokenOut,
+        uint256 minAmountOut,
         bool wrapEth,
         bool unwrapEth,
         uint256 nTokens,
-        bytes calldata swaps,
+        address receiver,
         IAllowanceTransfer.PermitSingle calldata permitSingle,
-        bytes calldata signature
+        bytes calldata signature,
-    ) external whenNotPaused returns (uint256 amountOut) {
+        bytes calldata swaps
-        amountOut = 0;
+    ) external payable whenNotPaused nonReentrant returns (uint256 amountOut) {
-        // TODO
+        require(receiver != address(0), "Invalid receiver address");
+
+        // For native ETH, assume funds already in our router. Else, transfer and handle approval.
+        if (wrapEth) {
+            _wrapETH(amountIn);
+        } else if (tokenIn != address(0)) {
+            permit2.permit(msg.sender, permitSingle, signature);
+            permit2.transferFrom(
+                msg.sender,
+                address(this),
+                uint160(amountIn),
+                permitSingle.details.token
+            );
+        }
+
+        amountOut = _swap(amountIn, nTokens, swaps);
+
+        if (fee > 0) {
+            uint256 feeAmount = (amountOut * fee) / 10000;
+            amountOut -= feeAmount;
+            IERC20(tokenOut).safeTransfer(feeReceiver, feeAmount);
+        }
+
+        if (minAmountOut > 0 && amountOut < minAmountOut) {
+            revert TychoRouter__NegativeSlippage(amountOut, minAmountOut);
+        }
+
+        if (unwrapEth) {
+            _unwrapETH(amountOut);
+            // slither-disable-next-line arbitrary-send-eth
+            payable(receiver).transfer(amountOut);
+        } else {
+            IERC20(tokenOut).safeTransfer(receiver, amountOut);
+        }
+    }
+
+    function _swap(uint256 amountIn, uint256 nTokens, bytes calldata swaps_)
+        internal
+        returns (uint256)
+    {
+        uint256 currentAmountIn;
+        uint256 currentAmountOut;
+        uint8 tokenInIndex;
+        uint8 tokenOutIndex;
+        uint24 split;
+        bytes calldata swapData;
+
+        uint256[] memory remainingAmounts = new uint256[](nTokens);
+        uint256[] memory amounts = new uint256[](nTokens);
+        amounts[0] = amountIn;
+        remainingAmounts[0] = amountIn;
+
+        while (swaps_.length > 0) {
+            (swapData, swaps_) = swaps_.next();
+            tokenInIndex = swapData.tokenInIndex();
+            tokenOutIndex = swapData.tokenOutIndex();
+            split = swapData.splitPercentage();
+            currentAmountIn = split > 0
+                ? (amounts[tokenInIndex] * split) / 0xffffff
+                : remainingAmounts[tokenInIndex];
+            currentAmountOut = _callExecutor(
+                swapData.executor(),
+                swapData.executorSelector(),
+                currentAmountIn,
+                swapData.protocolData()
+            );
+            amounts[tokenOutIndex] += currentAmountOut;
+            remainingAmounts[tokenOutIndex] += currentAmountOut;
+            remainingAmounts[tokenInIndex] -= currentAmountIn;
+        }
+        return amounts[tokenOutIndex];
     }
 
     /**
@@ -209,6 +315,27 @@ contract TychoRouter is
         }
     }
 
+    /**
+     * @dev Wraps a defined amount of ETH.
+     * @param amount of native ETH to wrap.
+     */
+    function _wrapETH(uint256 amount) internal {
+        if (msg.value > 0 && msg.value != amount) {
+            revert TychoRouter__MessageValueMismatch(msg.value, amount);
+        }
+        _weth.deposit{value: amount}();
+    }
+
+    /**
+     * @dev Unwraps a defined amount of WETH.
+     * @param amount of WETH to unwrap.
+     */
+    function _unwrapETH(uint256 amount) internal {
+        uint256 unwrapAmount =
+            amount == 0 ? _weth.balanceOf(address(this)) : amount;
+        _weth.withdraw(unwrapAmount);
+    }
+
     /**
      * @dev Allows this contract to receive native token
      */

foundry/src/executors/UniswapV2Executor.sol

@@ -10,8 +10,10 @@ error UniswapV2Executor__InvalidDataLength();
 contract UniswapV2Executor is IExecutor {
     using SafeERC20 for IERC20;
 
+    // slither-disable-next-line locked-ether
     function swap(uint256 givenAmount, bytes calldata data)
         external
+        payable
         returns (uint256 calculatedAmount)
     {
         address target;

foundry/test/CallbackVerificationDispatcher.t.sol

@@ -9,6 +9,7 @@ contract CallbackVerificationDispatcherExposed is
 {
     function exposedCallVerifier(bytes calldata data)
         external
+        view
         returns (
             uint256 amountOwed,
             uint256 amountReceived,
@@ -176,7 +177,7 @@ contract CallbackVerificationDispatcherTest is Constants {
         dispatcherExposed.exposedCallVerifier(data);
     }
 
-    function testDecodeVerifierAndSelector() public {
+    function testDecodeVerifierAndSelector() public view {
         bytes memory data =
             hex"2C960bD1CFE09A26105ad3C351bEa0a3fAD0F8e876b20f8aA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48";
         (address executor, bytes4 selector, bytes memory verifierData) =

foundry/test/Constants.sol

@@ -9,6 +9,10 @@ contract Constants is Test {
     address FUND_RESCUER = makeAddr("fundRescuer");
     address FEE_SETTER = makeAddr("feeSetter");
     address FEE_RECEIVER = makeAddr("feeReceiver");
+    address EXECUTOR_SETTER = makeAddr("executorSetter");
+    address ALICE = 0xcd09f75E2BF2A4d11F3AB23f1389FcC1621c0cc2;
+    uint256 ALICE_PK =
+        0x123456789abcdef123456789abcdef123456789abcdef123456789abcdef1234;
 
     // Dummy contracts
     address DUMMY = makeAddr("dummy");
@@ -18,6 +22,14 @@ contract Constants is Test {
     // Assets
     address WETH_ADDR = address(0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2);
     address DAI_ADDR = address(0x6B175474E89094C44Da98b954EedeAC495271d0F);
+    address USDC_ADDR = address(0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48);
+    address WBTC_ADDR = address(0x2260FAC5E5542a773Aa44fBCfeDf7C193bc2C599);
+
+    // uniswap v2
+    address WETH_DAI_POOL = 0xA478c2975Ab1Ea89e8196811F51A7B7Ade33eB11;
+    address DAI_USDC_POOL = 0xAE461cA67B15dc8dc81CE7615e0320dA1A9aB8D5;
+    address WETH_WBTC_POOL = 0xBb2b8038a1640196FbE3e38816F3e67Cba72D940;
+    address USDC_WBTC_POOL = 0x004375Dff511095CC5A197A54140a24eFEF3A416;
 
     /**
      * @dev Deploys a dummy contract with non-empty bytecode

foundry/test/ExecutionDispatcher.t.sol

@@ -5,19 +5,13 @@ import "@src/ExecutionDispatcher.sol";
 import "./TychoRouterTestSetup.sol";
 
 contract ExecutionDispatcherExposed is ExecutionDispatcher {
-    function exposedCallExecutor(uint256 amount, bytes calldata data)
+    function exposedCallExecutor(
-        external
+        address executor,
-        returns (uint256 calculatedAmount)
+        bytes4 selector,
-    {
+        uint256 amount,
-        return _callExecutor(amount, data);
+        bytes calldata data
-    }
+    ) external returns (uint256 calculatedAmount) {
-
+        return _callExecutor(executor, selector, amount, data);
-    function exposedDecodeExecutorAndSelector(bytes calldata data)
-        external
-        pure
-        returns (address executor, bytes4 selector, bytes memory protocolData)
-    {
-        return _decodeExecutorAndSelector(data);
     }
 
     function exposedSetExecutor(address target) external {
@@ -88,10 +82,14 @@ contract ExecutionDispatcherTest is Constants {
             address(0xe592557AB9F4A75D992283fD6066312FF013ba3d)
         );
         bytes memory data =
-            hex"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";
+            hex"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";
         uint256 givenAmount = 15 ether;
-        uint256 amount =
+        uint256 amount = dispatcherExposed.exposedCallExecutor(
-            dispatcherExposed.exposedCallExecutor(givenAmount, data);
+            0xe592557AB9F4A75D992283fD6066312FF013ba3d,
+            IExecutor.swap.selector,
+            givenAmount,
+            data
+        );
         assert(amount == 35144641819);
     }
 
@@ -111,10 +109,14 @@ contract ExecutionDispatcherTest is Constants {
             address(0xe592557AB9F4A75D992283fD6066312FF013ba3d)
         );
         bytes memory data =
-            hex"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";
+            hex"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";
         uint256 givenAmount = 15 ether;
-        uint256 amount =
+        uint256 amount = dispatcherExposed.exposedCallExecutor(
-            dispatcherExposed.exposedCallExecutor(givenAmount, data);
+            0xe592557AB9F4A75D992283fD6066312FF013ba3d,
+            bytes4(0),
+            givenAmount,
+            data
+        );
         assert(amount == 35144641819);
     }
 
@@ -124,26 +126,21 @@ contract ExecutionDispatcherTest is Constants {
             address(0xe592557AB9F4A75D992283fD6066312FF013ba3d)
         );
         bytes memory data =
-            hex"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";
+            hex"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";
         vm.expectRevert();
-        dispatcherExposed.exposedCallExecutor(0, data);
+        dispatcherExposed.exposedCallExecutor(
+            0xe592557AB9F4A75D992283fD6066312FF013ba3d,
+            IExecutor.swap.selector,
+            0,
+            data
+        );
     }
 
     function testCallExecutorUnapprovedExecutor() public {
-        bytes memory data =
+        bytes memory data = hex"aabbccdd1111111111111111";
-            hex"5d622C9053b8FFB1B3465495C8a42E603632bA70aabbccdd1111111111111111";
         vm.expectRevert();
-        dispatcherExposed.exposedCallExecutor(0, data);
+        dispatcherExposed.exposedCallExecutor(
-    }
+            0x5d622C9053b8FFB1B3465495C8a42E603632bA70, bytes4(0), 0, data
-
+        );
-    function testDecodeExecutorAndSelector() public {
-        bytes memory data =
-            hex"6611e616d2db3244244a54c754a16dd3ac7ca7a2aabbccdd1111111111111111";
-        (address executor, bytes4 selector, bytes memory protocolData) =
-            dispatcherExposed.exposedDecodeExecutorAndSelector(data);
-        assert(executor == address(0x6611e616d2db3244244A54c754A16dd3ac7cA7a2));
-        assert(selector == bytes4(0xaabbccdd));
-        // Direct bytes comparison not supported - must use keccak
-        assert(keccak256(protocolData) == keccak256(hex"1111111111111111"));
     }
 }

foundry/test/LibPrefixLengthEncodedByteArray.t.sol

@@ -8,14 +8,14 @@ import {LibPrefixLengthEncodedByteArray} from
 contract LibPrefixLengthEncodedByteArrayTest is Test {
     using LibPrefixLengthEncodedByteArray for bytes;
 
-    function testNextEmpty() public {
+    function testNextEmpty() public view {
         bytes memory encoded = "";
         (bytes memory elem, bytes memory remaining) = this.next(encoded);
         assertEq(elem.length, 0);
         assertEq(remaining.length, 0);
     }
 
-    function testNextSingleElement() public {
+    function testNextSingleElement() public view {
         // Create encoded data: length prefix (0003) followed by "ABC"
         bytes memory encoded = hex"0003414243";
         (bytes memory elem, bytes memory remaining) = this.next(encoded);
@@ -25,7 +25,7 @@ contract LibPrefixLengthEncodedByteArrayTest is Test {
         assertEq(remaining.length, 0);
     }
 
-    function testNextMultipleElements() public {
+    function testNextMultipleElements() public view {
         // Encoded data: [0003]ABC[0002]DE
         bytes memory encoded = hex"000341424300024445";
 
@@ -40,7 +40,7 @@ contract LibPrefixLengthEncodedByteArrayTest is Test {
         assertEq(remaining2.length, 0);
     }
 
-    function testSize() public {
+    function testSize() public view {
         bytes memory empty = "";
         assertEq(this.size(empty), 0);
 
@@ -51,19 +51,19 @@ contract LibPrefixLengthEncodedByteArrayTest is Test {
         assertEq(this.size(multiple), 3);
     }
 
-    function testFailInvalidLength() public {
+    function testFailInvalidLength() public view {
         // Length prefix larger than remaining data
         bytes memory invalid = hex"0004414243";
-        (bytes memory elem, bytes memory remaining) = this.next(invalid);
+        this.next(invalid);
     }
 
-    function testFailIncompletePrefix() public {
+    function testFailIncompletePrefix() public view {
         // Only 1 byte instead of 2 bytes prefix
         bytes memory invalid = hex"01";
-        (bytes memory elem, bytes memory remaining) = this.next(invalid);
+        this.next(invalid);
     }
 
-    function testLargeElement() public {
+    function testLargeElement() public view {
         // Test with a large but manageable size (1000 bytes)
         bytes memory large = new bytes(1002); // 2 bytes prefix + 1000 bytes data
         large[0] = bytes1(uint8(0x03)); // 03
@@ -79,7 +79,7 @@ contract LibPrefixLengthEncodedByteArrayTest is Test {
         assertEq(remaining.length, 0);
     }
 
-    function testSizeWithLargeElements() public {
+    function testSizeWithLargeElements() public view {
         // Two elements: 1000 bytes + 500 bytes
         bytes memory data = new bytes(1504); // 1000 + 2 + 500 + 2
 

foundry/test/LibSwap.t.sol

@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: UNLICENSED
+pragma solidity ^0.8.28;
+
+import "forge-std/Test.sol";
+import "../lib/LibSwap.sol";
+
+contract LibSwapTest is Test {
+    using LibSwap for bytes;
+
+    function testSwap() public view {
+        uint8 tokenInIndex = 1;
+        uint8 tokenOutIndex = 2;
+        uint24 split = 3;
+        address executor = 0x1234567890123456789012345678901234567890;
+        bytes4 selector = 0x12345678;
+        bytes memory protocolData = abi.encodePacked(uint256(456));
+
+        bytes memory swap = abi.encodePacked(
+            tokenInIndex, tokenOutIndex, split, executor, selector, protocolData
+        );
+        this.assertSwap(
+            swap, tokenInIndex, tokenOutIndex, split, executor, selector
+        );
+    }
+
+    // This is necessary so that the compiler accepts bytes as a LibSwap.sol
+    function assertSwap(
+        bytes calldata swap,
+        uint8 tokenInIndex,
+        uint8 tokenOutIndex,
+        uint24 split,
+        address executor,
+        bytes4 selector
+    ) public pure {
+        assert(swap.tokenInIndex() == tokenInIndex);
+        assert(swap.tokenOutIndex() == tokenOutIndex);
+        assert(swap.splitPercentage() == split);
+        assert(swap.executor() == executor);
+        assert(swap.executorSelector() == selector);
+    }
+}

foundry/test/TychoRouter.t.sol

@@ -20,14 +20,14 @@ contract TychoRouterTest is TychoRouterTestSetup {
     );
 
     function testSetExecutorValidRole() public {
-        vm.startPrank(executorSetter);
+        vm.startPrank(EXECUTOR_SETTER);
         tychoRouter.setExecutor(DUMMY);
         vm.stopPrank();
         assert(tychoRouter.executors(DUMMY) == true);
     }
 
     function testRemoveExecutorValidRole() public {
-        vm.startPrank(executorSetter);
+        vm.startPrank(EXECUTOR_SETTER);
         tychoRouter.setExecutor(DUMMY);
         tychoRouter.removeExecutor(DUMMY);
         vm.stopPrank();
@@ -45,14 +45,14 @@ contract TychoRouterTest is TychoRouterTestSetup {
     }
 
     function testSetVerifierValidRole() public {
-        vm.startPrank(executorSetter);
+        vm.startPrank(EXECUTOR_SETTER);
         tychoRouter.setCallbackVerifier(DUMMY);
         vm.stopPrank();
         assert(tychoRouter.callbackVerifiers(DUMMY) == true);
     }
 
     function testRemoveVerifierValidRole() public {
-        vm.startPrank(executorSetter);
+        vm.startPrank(EXECUTOR_SETTER);
         tychoRouter.setCallbackVerifier(DUMMY);
         tychoRouter.removeCallbackVerifier(DUMMY);
         vm.stopPrank();
@@ -72,19 +72,19 @@ contract TychoRouterTest is TychoRouterTestSetup {
     function testWithdrawNative() public {
         vm.startPrank(FUND_RESCUER);
         // Send 100 ether to tychoRouter
-        assertEq(address(tychoRouter).balance, 0);
+        assertEq(tychoRouterAddr.balance, 0);
         assertEq(FUND_RESCUER.balance, 0);
-        vm.deal(address(tychoRouter), 100 ether);
+        vm.deal(tychoRouterAddr, 100 ether);
         vm.expectEmit();
         emit Withdrawal(address(0), 100 ether, FUND_RESCUER);
         tychoRouter.withdrawNative(FUND_RESCUER);
-        assertEq(address(tychoRouter).balance, 0);
+        assertEq(tychoRouterAddr.balance, 0);
         assertEq(FUND_RESCUER.balance, 100 ether);
         vm.stopPrank();
     }
 
     function testWithdrawNativeFailures() public {
-        vm.deal(address(tychoRouter), 100 ether);
+        vm.deal(tychoRouterAddr, 100 ether);
         vm.startPrank(FUND_RESCUER);
         vm.expectRevert(TychoRouter__AddressZero.selector);
         tychoRouter.withdrawNative(address(0));
@@ -99,7 +99,7 @@ contract TychoRouterTest is TychoRouterTestSetup {
 
     function testWithdrawERC20Tokens() public {
         vm.startPrank(BOB);
-        mintTokens(100 ether, address(tychoRouter));
+        mintTokens(100 ether, tychoRouterAddr);
         vm.stopPrank();
 
         vm.startPrank(FUND_RESCUER);
@@ -112,7 +112,7 @@ contract TychoRouterTest is TychoRouterTestSetup {
         // Check balances after withdrawing
         for (uint256 i = 0; i < tokens.length; i++) {
             // slither-disable-next-line calls-loop
-            assertEq(tokens[i].balanceOf(address(tychoRouter)), 0);
+            assertEq(tokens[i].balanceOf(tychoRouterAddr), 0);
             // slither-disable-next-line calls-loop
             assertEq(tokens[i].balanceOf(FUND_RESCUER), 100 ether);
         }
@@ -120,7 +120,7 @@ contract TychoRouterTest is TychoRouterTestSetup {
     }
 
     function testWithdrawERC20TokensFailures() public {
-        mintTokens(100 ether, address(tychoRouter));
+        mintTokens(100 ether, tychoRouterAddr);
         IERC20[] memory tokensArray = new IERC20[](3);
         tokensArray[0] = IERC20(address(tokens[0]));
         tokensArray[1] = IERC20(address(tokens[1]));
@@ -189,4 +189,421 @@ contract TychoRouterTest is TychoRouterTestSetup {
         tychoRouter.pause();
         vm.stopPrank();
     }
+
+    function testWrapETH() public {
+        uint256 amount = 1 ether;
+        vm.deal(BOB, amount);
+
+        vm.startPrank(BOB);
+        tychoRouter.wrapETH{value: amount}(amount);
+        vm.stopPrank();
+
+        assertEq(tychoRouterAddr.balance, 0);
+        assertEq(IERC20(WETH_ADDR).balanceOf(tychoRouterAddr), amount);
+    }
+
+    function testUnwrapETH() public {
+        uint256 amount = 1 ether;
+        deal(WETH_ADDR, tychoRouterAddr, amount);
+
+        tychoRouter.unwrapETH(amount);
+
+        assertEq(tychoRouterAddr.balance, amount);
+        assertEq(IERC20(WETH_ADDR).balanceOf(tychoRouterAddr), 0);
+    }
+
+    function testSwapSimple() public {
+        // Trade 1 WETH for DAI with 1 swap on Uniswap V2
+        // 1 WETH   ->   DAI
+        //       (univ2)
+        uint256 amountIn = 1 ether;
+        deal(WETH_ADDR, tychoRouterAddr, amountIn);
+
+        bytes memory protocolData = encodeUniswapV2Swap(
+            WETH_ADDR, WETH_DAI_POOL, tychoRouterAddr, false
+        );
+
+        bytes memory swap = encodeSwap(
+            uint8(0),
+            uint8(1),
+            uint24(0),
+            address(usv2Executor),
+            bytes4(0),
+            protocolData
+        );
+        bytes[] memory swaps = new bytes[](1);
+        swaps[0] = swap;
+
+        tychoRouter.ExposedSwap(amountIn, 2, pleEncode(swaps));
+
+        uint256 daiBalance = IERC20(DAI_ADDR).balanceOf(tychoRouterAddr);
+        assertEq(daiBalance, 2630432278145144658455);
+        assertEq(IERC20(WETH_ADDR).balanceOf(tychoRouterAddr), 0);
+    }
+
+    function testSwapMultipleHops() public {
+        // Trade 1 WETH for USDC through DAI with 2 swaps on Uniswap V2
+        // 1 WETH   ->   DAI   ->   USDC
+        //       (univ2)     (univ2)
+        uint256 amountIn = 1 ether;
+        deal(WETH_ADDR, tychoRouterAddr, amountIn);
+
+        bytes[] memory swaps = new bytes[](2);
+        // WETH -> DAI
+        swaps[0] = encodeSwap(
+            uint8(0),
+            uint8(1),
+            uint24(0),
+            address(usv2Executor),
+            bytes4(0),
+            encodeUniswapV2Swap(
+                WETH_ADDR, WETH_DAI_POOL, tychoRouterAddr, false
+            )
+        );
+
+        // DAI -> USDC
+        swaps[1] = encodeSwap(
+            uint8(1),
+            uint8(2),
+            uint24(0),
+            address(usv2Executor),
+            bytes4(0),
+            encodeUniswapV2Swap(DAI_ADDR, DAI_USDC_POOL, tychoRouterAddr, true)
+        );
+
+        tychoRouter.ExposedSwap(amountIn, 3, pleEncode(swaps));
+
+        uint256 usdcBalance = IERC20(USDC_ADDR).balanceOf(tychoRouterAddr);
+        assertEq(usdcBalance, 2610580090);
+        assertEq(IERC20(WETH_ADDR).balanceOf(tychoRouterAddr), 0);
+    }
+
+    function testSwapSplitHops() public {
+        // Trade 1 WETH for USDC through DAI and WBTC with 4 swaps on Uniswap V2
+        //          ->   DAI   ->
+        // 1 WETH                   USDC
+        //          ->   WBTC  ->
+        //       (univ2)     (univ2)
+        uint256 amountIn = 1 ether;
+        deal(WETH_ADDR, tychoRouterAddr, amountIn);
+
+        bytes[] memory swaps = new bytes[](4);
+        // WETH -> WBTC (60%)
+        swaps[0] = encodeSwap(
+            uint8(0),
+            uint8(1),
+            (0xffffff * 60) / 100, // 60%
+            address(usv2Executor),
+            bytes4(0),
+            encodeUniswapV2Swap(
+                WETH_ADDR, WETH_WBTC_POOL, tychoRouterAddr, false
+            )
+        );
+        // WBTC -> USDC
+        swaps[1] = encodeSwap(
+            uint8(1),
+            uint8(2),
+            uint24(0),
+            address(usv2Executor),
+            bytes4(0),
+            encodeUniswapV2Swap(
+                WBTC_ADDR, USDC_WBTC_POOL, tychoRouterAddr, true
+            )
+        );
+        // WETH -> DAI
+        swaps[2] = encodeSwap(
+            uint8(0),
+            uint8(3),
+            uint24(0),
+            address(usv2Executor),
+            bytes4(0),
+            encodeUniswapV2Swap(
+                WETH_ADDR, WETH_DAI_POOL, tychoRouterAddr, false
+            )
+        );
+
+        // DAI -> USDC
+        swaps[3] = encodeSwap(
+            uint8(3),
+            uint8(2),
+            uint24(0),
+            address(usv2Executor),
+            bytes4(0),
+            encodeUniswapV2Swap(DAI_ADDR, DAI_USDC_POOL, tychoRouterAddr, true)
+        );
+
+        tychoRouter.ExposedSwap(amountIn, 4, pleEncode(swaps));
+
+        uint256 usdcBalance = IERC20(USDC_ADDR).balanceOf(tychoRouterAddr);
+        assertEq(usdcBalance, 2581503157);
+        assertEq(IERC20(WETH_ADDR).balanceOf(tychoRouterAddr), 0);
+    }
+
+    function testSwapChecked() public {
+        // Trade 1 WETH for DAI with 1 swap on Uniswap V2
+        // Does permit2 token approval and transfer
+        // Checks amount out at the end
+        uint256 amountIn = 1 ether;
+        deal(WETH_ADDR, ALICE, amountIn);
+
+        vm.startPrank(ALICE);
+
+        (
+            IAllowanceTransfer.PermitSingle memory permitSingle,
+            bytes memory signature
+        ) = handlePermit2Approval(WETH_ADDR, amountIn);
+
+        bytes memory protocolData = encodeUniswapV2Swap(
+            WETH_ADDR, WETH_DAI_POOL, tychoRouterAddr, false
+        );
+
+        bytes memory swap = encodeSwap(
+            uint8(0),
+            uint8(1),
+            uint24(0),
+            address(usv2Executor),
+            bytes4(0),
+            protocolData
+        );
+        bytes[] memory swaps = new bytes[](1);
+        swaps[0] = swap;
+
+        uint256 minAmountOut = 2600 * 1e18;
+        uint256 amountOut = tychoRouter.swap(
+            amountIn,
+            WETH_ADDR,
+            DAI_ADDR,
+            minAmountOut,
+            false,
+            false,
+            2,
+            ALICE,
+            permitSingle,
+            signature,
+            pleEncode(swaps)
+        );
+
+        uint256 expectedAmount = 2630432278145144658455;
+        assertEq(amountOut, expectedAmount);
+        uint256 daiBalance = IERC20(DAI_ADDR).balanceOf(ALICE);
+        assertEq(daiBalance, expectedAmount);
+        assertEq(IERC20(WETH_ADDR).balanceOf(ALICE), 0);
+
+        vm.stopPrank();
+    }
+
+    function testSwapCheckedFailure() public {
+        // Trade 1 WETH for DAI with 1 swap on Uniswap V2
+        // Does permit2 token approval and transfer
+        // Checks amount out at the end and fails
+        uint256 amountIn = 1 ether;
+        deal(WETH_ADDR, ALICE, amountIn);
+
+        vm.startPrank(ALICE);
+
+        (
+            IAllowanceTransfer.PermitSingle memory permitSingle,
+            bytes memory signature
+        ) = handlePermit2Approval(WETH_ADDR, amountIn);
+
+        bytes memory protocolData = encodeUniswapV2Swap(
+            WETH_ADDR, WETH_DAI_POOL, tychoRouterAddr, false
+        );
+
+        bytes memory swap = encodeSwap(
+            uint8(0),
+            uint8(1),
+            uint24(0),
+            address(usv2Executor),
+            bytes4(0),
+            protocolData
+        );
+        bytes[] memory swaps = new bytes[](1);
+        swaps[0] = swap;
+
+        uint256 minAmountOut = 3000 * 1e18;
+        vm.expectRevert(
+            abi.encodeWithSelector(
+                TychoRouter__NegativeSlippage.selector,
+                2630432278145144658455, // actual amountOut
+                minAmountOut
+            )
+        );
+        tychoRouter.swap(
+            amountIn,
+            WETH_ADDR,
+            DAI_ADDR,
+            minAmountOut,
+            false,
+            false,
+            2,
+            ALICE,
+            permitSingle,
+            signature,
+            pleEncode(swaps)
+        );
+        vm.stopPrank();
+    }
+
+    function testSwapFee() public {
+        // Trade 1 WETH for DAI with 1 swap on Uniswap V2
+        // Does permit2 token approval and transfer
+        // Takes fee at the end
+
+        vm.startPrank(FEE_SETTER);
+        tychoRouter.setFee(100);
+        tychoRouter.setFeeReceiver(FEE_RECEIVER);
+        vm.stopPrank();
+
+        uint256 amountIn = 1 ether;
+        deal(WETH_ADDR, ALICE, amountIn);
+
+        vm.startPrank(ALICE);
+
+        (
+            IAllowanceTransfer.PermitSingle memory permitSingle,
+            bytes memory signature
+        ) = handlePermit2Approval(WETH_ADDR, amountIn);
+
+        bytes memory protocolData = encodeUniswapV2Swap(
+            WETH_ADDR, WETH_DAI_POOL, tychoRouterAddr, false
+        );
+
+        bytes memory swap = encodeSwap(
+            uint8(0),
+            uint8(1),
+            uint24(0),
+            address(usv2Executor),
+            bytes4(0),
+            protocolData
+        );
+        bytes[] memory swaps = new bytes[](1);
+        swaps[0] = swap;
+
+        uint256 amountOut = tychoRouter.swap(
+            amountIn,
+            WETH_ADDR,
+            DAI_ADDR,
+            0,
+            false,
+            false,
+            2,
+            ALICE,
+            permitSingle,
+            signature,
+            pleEncode(swaps)
+        );
+
+        uint256 expectedAmount = 2604127955363693211871;
+        assertEq(amountOut, expectedAmount);
+        uint256 daiBalance = IERC20(DAI_ADDR).balanceOf(ALICE);
+        assertEq(daiBalance, expectedAmount);
+        assertEq(IERC20(DAI_ADDR).balanceOf(FEE_RECEIVER), 26304322781451446584);
+
+        vm.stopPrank();
+    }
+
+    function testSwapWrapETH() public {
+        // Trade 1 ETH (and wrap it) for DAI with 1 swap on Uniswap V2
+
+        uint256 amountIn = 1 ether;
+        deal(ALICE, amountIn);
+
+        vm.startPrank(ALICE);
+
+        IAllowanceTransfer.PermitSingle memory emptyPermitSingle =
+        IAllowanceTransfer.PermitSingle({
+            details: IAllowanceTransfer.PermitDetails({
+                token: address(0),
+                amount: 0,
+                expiration: 0,
+                nonce: 0
+            }),
+            spender: address(0),
+            sigDeadline: 0
+        });
+        bytes memory protocolData = encodeUniswapV2Swap(
+            WETH_ADDR, WETH_DAI_POOL, tychoRouterAddr, false
+        );
+
+        bytes memory swap = encodeSwap(
+            uint8(0),
+            uint8(1),
+            uint24(0),
+            address(usv2Executor),
+            bytes4(0),
+            protocolData
+        );
+        bytes[] memory swaps = new bytes[](1);
+        swaps[0] = swap;
+
+        uint256 amountOut = tychoRouter.swap{value: amountIn}(
+            amountIn,
+            address(0),
+            DAI_ADDR,
+            0,
+            true,
+            false,
+            2,
+            ALICE,
+            emptyPermitSingle,
+            "",
+            pleEncode(swaps)
+        );
+        uint256 expectedAmount = 2630432278145144658455;
+        assertEq(amountOut, expectedAmount);
+        uint256 daiBalance = IERC20(DAI_ADDR).balanceOf(ALICE);
+        assertEq(daiBalance, expectedAmount);
+        assertEq(ALICE.balance, 0);
+
+        vm.stopPrank();
+    }
+
+    function testSwapUnwrapETH() public {
+        // Trade 3k DAI for WETH with 1 swap on Uniswap V2 and unwrap it at the end
+
+        uint256 amountIn = 3_000 * 10 ** 18;
+        deal(DAI_ADDR, ALICE, amountIn);
+
+        vm.startPrank(ALICE);
+
+        (
+            IAllowanceTransfer.PermitSingle memory permitSingle,
+            bytes memory signature
+        ) = handlePermit2Approval(DAI_ADDR, amountIn);
+
+        bytes memory protocolData =
+            encodeUniswapV2Swap(DAI_ADDR, WETH_DAI_POOL, tychoRouterAddr, true);
+
+        bytes memory swap = encodeSwap(
+            uint8(0),
+            uint8(1),
+            uint24(0),
+            address(usv2Executor),
+            bytes4(0),
+            protocolData
+        );
+        bytes[] memory swaps = new bytes[](1);
+        swaps[0] = swap;
+
+        uint256 amountOut = tychoRouter.swap(
+            amountIn,
+            DAI_ADDR,
+            address(0),
+            0,
+            false,
+            true,
+            2,
+            ALICE,
+            permitSingle,
+            signature,
+            pleEncode(swaps)
+        );
+
+        uint256 expectedAmount = 1132829934891544187; // 1.13 ETH
+        assertEq(amountOut, expectedAmount);
+        assertEq(ALICE.balance, expectedAmount);
+
+        vm.stopPrank();
+    }
 }

foundry/test/TychoRouterTestSetup.sol

@@ -1,28 +1,61 @@
 // SPDX-License-Identifier: UNLICENSED
 pragma solidity ^0.8.13;
 
-import "@src/TychoRouter.sol";
+import "../src/executors/UniswapV2Executor.sol";
 import "./Constants.sol";
 import "./mock/MockERC20.sol";
+import "@src/TychoRouter.sol";
+import {WETH} from "../lib/permit2/lib/solmate/src/tokens/WETH.sol";
+
+contract TychoRouterExposed is TychoRouter {
+    constructor(address _permit2, address weth) TychoRouter(_permit2, weth) {}
+
+    function wrapETH(uint256 amount) external payable {
+        return _wrapETH(amount);
+    }
+
+    function unwrapETH(uint256 amount) external {
+        return _unwrapETH(amount);
+    }
+
+    function ExposedSwap(
+        uint256 amountIn,
+        uint256 nTokens,
+        bytes calldata swaps
+    ) external returns (uint256) {
+        return _swap(amountIn, nTokens, swaps);
+    }
+}
 
 contract TychoRouterTestSetup is Test, Constants {
-    TychoRouter tychoRouter;
+    TychoRouterExposed tychoRouter;
-    address executorSetter;
+    address tychoRouterAddr;
     address permit2Address = address(0x000000000022D473030F116dDEE9F6B43aC78BA3);
+    UniswapV2Executor public usv2Executor;
     MockERC20[] tokens;
 
     function setUp() public {
+        uint256 forkBlock = 21000000;
+        vm.createSelectFork(vm.rpcUrl("mainnet"), forkBlock);
+
         vm.startPrank(ADMIN);
-        tychoRouter = new TychoRouter(permit2Address);
+        tychoRouter = new TychoRouterExposed(permit2Address, WETH_ADDR);
-        tychoRouter.grantRole(keccak256("EXECUTOR_SETTER_ROLE"), BOB);
+        tychoRouterAddr = address(tychoRouter);
         tychoRouter.grantRole(keccak256("FUND_RESCUER_ROLE"), FUND_RESCUER);
         tychoRouter.grantRole(keccak256("FEE_SETTER_ROLE"), FEE_SETTER);
         tychoRouter.grantRole(keccak256("PAUSER_ROLE"), PAUSER);
         tychoRouter.grantRole(keccak256("UNPAUSER_ROLE"), UNPAUSER);
-        executorSetter = BOB;
+        tychoRouter.grantRole(
+            keccak256("EXECUTOR_SETTER_ROLE"), EXECUTOR_SETTER
+        );
         deployDummyContract();
         vm.stopPrank();
 
+        usv2Executor = new UniswapV2Executor();
+        vm.startPrank(EXECUTOR_SETTER);
+        tychoRouter.setExecutor(address(usv2Executor));
+        vm.stopPrank();
+
         vm.startPrank(BOB);
         tokens.push(new MockERC20("Token A", "A"));
         tokens.push(new MockERC20("Token B", "B"));
@@ -41,4 +74,117 @@ contract TychoRouterTestSetup is Test, Constants {
             tokens[i].mint(to, amount);
         }
     }
+
+    /**
+     * @dev Handles the Permit2 approval process for Alice, allowing the TychoRouter contract
+     *      to spend `amount_in` of `tokenIn` on her behalf.
+     *
+     * This function approves the Permit2 contract to transfer the specified token amount
+     * and constructs a `PermitSingle` struct for the approval. It also generates a valid
+     * EIP-712 signature for the approval using Alice's private key.
+     *
+     * @param tokenIn The address of the token being approved.
+     * @param amount_in The amount of tokens to approve for transfer.
+     * @return permitSingle The `PermitSingle` struct containing the approval details.
+     * @return signature The EIP-712 signature for the approval.
+     */
+    function handlePermit2Approval(address tokenIn, uint256 amount_in)
+        internal
+        returns (IAllowanceTransfer.PermitSingle memory, bytes memory)
+    {
+        IERC20(tokenIn).approve(permit2Address, amount_in);
+        IAllowanceTransfer.PermitSingle memory permitSingle = IAllowanceTransfer
+            .PermitSingle({
+            details: IAllowanceTransfer.PermitDetails({
+                token: tokenIn,
+                amount: uint160(amount_in),
+                expiration: uint48(block.timestamp + 1 days),
+                nonce: 0
+            }),
+            spender: tychoRouterAddr,
+            sigDeadline: block.timestamp + 1 days
+        });
+
+        bytes memory signature = signPermit2(permitSingle, ALICE_PK);
+        return (permitSingle, signature);
+    }
+
+    /**
+     * @dev Signs a Permit2 `PermitSingle` struct with the given private key.
+     * @param permit The `PermitSingle` struct to sign.
+     * @param privateKey The private key of the signer.
+     * @return The signature as a `bytes` array.
+     */
+    function signPermit2(
+        IAllowanceTransfer.PermitSingle memory permit,
+        uint256 privateKey
+    ) internal view returns (bytes memory) {
+        bytes32 _PERMIT_DETAILS_TYPEHASH = keccak256(
+            "PermitDetails(address token,uint160 amount,uint48 expiration,uint48 nonce)"
+        );
+        bytes32 _PERMIT_SINGLE_TYPEHASH = keccak256(
+            "PermitSingle(PermitDetails details,address spender,uint256 sigDeadline)PermitDetails(address token,uint160 amount,uint48 expiration,uint48 nonce)"
+        );
+        bytes32 domainSeparator = keccak256(
+            abi.encode(
+                keccak256(
+                    "EIP712Domain(string name,uint256 chainId,address verifyingContract)"
+                ),
+                keccak256("Permit2"),
+                block.chainid,
+                permit2Address
+            )
+        );
+        bytes32 detailsHash =
+            keccak256(abi.encode(_PERMIT_DETAILS_TYPEHASH, permit.details));
+        bytes32 permitHash = keccak256(
+            abi.encode(
+                _PERMIT_SINGLE_TYPEHASH,
+                detailsHash,
+                permit.spender,
+                permit.sigDeadline
+            )
+        );
+
+        bytes32 digest =
+            keccak256(abi.encodePacked("\x19\x01", domainSeparator, permitHash));
+        (uint8 v, bytes32 r, bytes32 s) = vm.sign(privateKey, digest);
+
+        return abi.encodePacked(r, s, v);
+    }
+
+    function pleEncode(bytes[] memory data)
+        public
+        pure
+        returns (bytes memory encoded)
+    {
+        for (uint256 i = 0; i < data.length; i++) {
+            encoded = bytes.concat(
+                encoded,
+                abi.encodePacked(bytes2(uint16(data[i].length)), data[i])
+            );
+        }
+    }
+
+    function encodeSwap(
+        uint8 tokenInIndex,
+        uint8 tokenOutIndex,
+        uint24 split,
+        address executor,
+        bytes4 selector,
+        bytes memory protocolData
+    ) internal pure returns (bytes memory) {
+        return abi.encodePacked(
+            tokenInIndex, tokenOutIndex, split, executor, selector, protocolData
+        );
+    }
+
+    function encodeUniswapV2Swap(
+        address tokenIn,
+        address target,
+        address receiver,
+        bool zero2one
+    ) internal pure returns (bytes memory) {
+        return abi.encodePacked(tokenIn, target, receiver, zero2one);
+    }
 }

foundry/test/executors/UniswapV2Executor.t.sol

@@ -34,7 +34,6 @@ contract UniswapV2ExecutorTest is UniswapV2ExecutorExposed, Test, Constants {
     UniswapV2ExecutorExposed uniswapV2Exposed;
     IERC20 WETH = IERC20(WETH_ADDR);
     IERC20 DAI = IERC20(DAI_ADDR);
-    address WETH_DAI_POOL = 0xA478c2975Ab1Ea89e8196811F51A7B7Ade33eB11;
 
     function setUp() public {
         uint256 forkBlock = 17323404;