refactor: create Permit2TestHelper

- To avoid duplicating permit2 setup code for TychoRouter and executor tests.

foundry/src/executors/ExecutorTransferMethods.sol

@@ -4,7 +4,6 @@ pragma solidity ^0.8.26;
 import "@interfaces/IExecutor.sol";
 import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
 import "@permit2/src/interfaces/IAllowanceTransfer.sol";
-import "@permit2/src/interfaces/IAllowanceTransfer.sol";
 
 error ExecutorTransferMethods__InvalidPermit2();
 
@@ -45,10 +44,7 @@ contract ExecutorTransferMethods {
         } else if (method == TransferMethod.TRANSFERPERMIT2) {
             // Permit2.permit is already called from the TychoRouter
             permit2.transferFrom(
-                sender,
-                receiver,
-                uint160(amount),
-                address(tokenIn)
+                sender, receiver, uint160(amount), address(tokenIn)
             );
         } else {
             // Funds are likely already in pool. Do nothing.

foundry/test/Permit2TestHelper.sol

@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: BUSL-1.1
+pragma solidity ^0.8.26;
+
+import "./Constants.sol";
+import "@permit2/src/interfaces/IAllowanceTransfer.sol";
+import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
+
+contract Permit2TestHelper is Constants {
+    /**
+     * @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,
+        address spender,
+        uint256 amount_in
+    ) internal returns (IAllowanceTransfer.PermitSingle memory, bytes memory) {
+        IERC20(tokenIn).approve(PERMIT2_ADDRESS, 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: spender,
+            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,
+                PERMIT2_ADDRESS
+            )
+        );
+        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);
+    }
+}

foundry/test/TychoRouterSequentialSwap.t.sol

@@ -51,7 +51,7 @@ contract TychoRouterSequentialSwapTest is TychoRouterTestSetup {
         (
             IAllowanceTransfer.PermitSingle memory permitSingle,
             bytes memory signature
-        ) = handlePermit2Approval(WETH_ADDR, amountIn);
+        ) = handlePermit2Approval(WETH_ADDR, tychoRouterAddr, amountIn);
 
         bytes[] memory swaps = _getSequentialSwaps();
         tychoRouter.sequentialSwapPermit2(
@@ -150,7 +150,7 @@ contract TychoRouterSequentialSwapTest is TychoRouterTestSetup {
         (
             IAllowanceTransfer.PermitSingle memory permitSingle,
             bytes memory signature
-        ) = handlePermit2Approval(WETH_ADDR, amountIn);
+        ) = handlePermit2Approval(WETH_ADDR, tychoRouterAddr, amountIn);
 
         bytes[] memory swaps = _getSequentialSwaps();
 
@@ -229,7 +229,7 @@ contract TychoRouterSequentialSwapTest is TychoRouterTestSetup {
         (
             IAllowanceTransfer.PermitSingle memory permitSingle,
             bytes memory signature
-        ) = handlePermit2Approval(USDC_ADDR, amountIn);
+        ) = handlePermit2Approval(USDC_ADDR, tychoRouterAddr, amountIn);
 
         bytes[] memory swaps = new bytes[](2);
 

foundry/test/TychoRouterSingleSwap.t.sol

@@ -19,7 +19,7 @@ contract TychoRouterSingleSwapTest is TychoRouterTestSetup {
         (
             IAllowanceTransfer.PermitSingle memory permitSingle,
             bytes memory signature
-        ) = handlePermit2Approval(WETH_ADDR, amountIn);
+        ) = handlePermit2Approval(WETH_ADDR, tychoRouterAddr, amountIn);
 
         bytes memory protocolData = encodeUniswapV2Swap(
             WETH_ADDR, WETH_DAI_POOL, tychoRouterAddr, false
@@ -230,7 +230,7 @@ contract TychoRouterSingleSwapTest is TychoRouterTestSetup {
         (
             IAllowanceTransfer.PermitSingle memory permitSingle,
             bytes memory signature
-        ) = handlePermit2Approval(DAI_ADDR, amountIn);
+        ) = handlePermit2Approval(DAI_ADDR, tychoRouterAddr, amountIn);
 
         bytes memory protocolData =
             encodeUniswapV2Swap(DAI_ADDR, WETH_DAI_POOL, tychoRouterAddr, true);

foundry/test/TychoRouterSplitSwap.t.sol

@@ -81,7 +81,7 @@ contract TychoRouterSplitSwapTest is TychoRouterTestSetup {
         (
             IAllowanceTransfer.PermitSingle memory permitSingle,
             bytes memory signature
-        ) = handlePermit2Approval(WETH_ADDR, amountIn);
+        ) = handlePermit2Approval(WETH_ADDR, tychoRouterAddr, amountIn);
 
         bytes[] memory swaps = _getSplitSwaps();
 
@@ -191,7 +191,7 @@ contract TychoRouterSplitSwapTest is TychoRouterTestSetup {
         (
             IAllowanceTransfer.PermitSingle memory permitSingle,
             bytes memory signature
-        ) = handlePermit2Approval(WETH_ADDR, amountIn);
+        ) = handlePermit2Approval(WETH_ADDR, tychoRouterAddr, amountIn);
 
         bytes[] memory swaps = _getSplitSwaps();
 
@@ -282,7 +282,7 @@ contract TychoRouterSplitSwapTest is TychoRouterTestSetup {
         (
             IAllowanceTransfer.PermitSingle memory permitSingle,
             bytes memory signature
-        ) = handlePermit2Approval(DAI_ADDR, amountIn);
+        ) = handlePermit2Approval(DAI_ADDR, tychoRouterAddr, amountIn);
 
         bytes memory protocolData =
             encodeUniswapV2Swap(DAI_ADDR, WETH_DAI_POOL, tychoRouterAddr, true);
@@ -325,7 +325,7 @@ contract TychoRouterSplitSwapTest is TychoRouterTestSetup {
         (
             IAllowanceTransfer.PermitSingle memory permitSingle,
             bytes memory signature
-        ) = handlePermit2Approval(WETH_ADDR, amountIn);
+        ) = handlePermit2Approval(WETH_ADDR, tychoRouterAddr, amountIn);
 
         uint256 expAmountOut = 1205_128428842122129186; //Swap 1 WETH for 1205.12 DAI
         bool zeroForOne = false;
@@ -377,7 +377,7 @@ contract TychoRouterSplitSwapTest is TychoRouterTestSetup {
         (
             IAllowanceTransfer.PermitSingle memory permitSingle,
             bytes memory signature
-        ) = handlePermit2Approval(WETH_ADDR, amountIn);
+        ) = handlePermit2Approval(WETH_ADDR, tychoRouterAddr, amountIn);
 
         bytes memory protocolData = encodeUniswapV2Swap(
             WETH_ADDR, WETH_DAI_POOL, tychoRouterAddr, false
@@ -426,7 +426,7 @@ contract TychoRouterSplitSwapTest is TychoRouterTestSetup {
         (
             IAllowanceTransfer.PermitSingle memory permitSingle,
             bytes memory signature
-        ) = handlePermit2Approval(USDE_ADDR, amountIn);
+        ) = handlePermit2Approval(USDE_ADDR, tychoRouterAddr, amountIn);
 
         UniswapV4Executor.UniswapV4Pool[] memory pools =
             new UniswapV4Executor.UniswapV4Pool[](1);

foundry/test/TychoRouterTestSetup.sol

@@ -13,6 +13,7 @@ import "@src/TychoRouter.sol";
 import {IPoolManager} from "@uniswap/v4-core/src/interfaces/IPoolManager.sol";
 import {PoolManager} from "@uniswap/v4-core/src/PoolManager.sol";
 import {WETH} from "../lib/permit2/lib/solmate/src/tokens/WETH.sol";
+import {Permit2TestHelper} from "./Permit2TestHelper.sol";
 
 contract TychoRouterExposed is TychoRouter {
     constructor(address _permit2, address weth) TychoRouter(_permit2, weth) {}
@@ -41,7 +42,7 @@ contract TychoRouterExposed is TychoRouter {
     }
 }
 
-contract TychoRouterTestSetup is Constants {
+contract TychoRouterTestSetup is Constants, Permit2TestHelper {
     TychoRouterExposed tychoRouter;
     address tychoRouterAddr;
     UniswapV2Executor public usv2Executor;
@@ -132,84 +133,6 @@ contract TychoRouterTestSetup is Constants {
         }
     }
 
-    /**
-     * @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(PERMIT2_ADDRESS, 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,
-                PERMIT2_ADDRESS
-            )
-        );
-        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

foundry/test/executors/UniswapV2Executor.t.sol

@@ -5,6 +5,7 @@ import "@src/executors/UniswapV2Executor.sol";
 import "@src/executors/ExecutorTransferMethods.sol";
 import {Test} from "../../lib/forge-std/src/Test.sol";
 import {Constants} from "../Constants.sol";
+import {Permit2TestHelper} from "../Permit2TestHelper.sol";
 
 contract UniswapV2ExecutorExposed is UniswapV2Executor {
     constructor(address _factory, bytes32 _initCode, address _permit2)
@@ -48,7 +49,7 @@ contract FakeUniswapV2Pool {
     }
 }
 
-contract UniswapV2ExecutorTest is Test, Constants {
+contract UniswapV2ExecutorTest is Test, Constants, Permit2TestHelper {
     using SafeERC20 for IERC20;
 
     UniswapV2ExecutorExposed uniswapV2Exposed;
@@ -188,86 +189,6 @@ contract UniswapV2ExecutorTest is Test, Constants {
         assertGe(finalBalance, amountOut);
     }
 
-    // TODO generalize these next two methods - don't reuse from TychoRouterTestSetup
-    /**
-     * @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(PERMIT2_ADDRESS, 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: address(uniswapV2Exposed),
-            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,
-                PERMIT2_ADDRESS
-            )
-        );
-        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 testSwapWithPermit2TransferFrom() public {
         uint256 amountIn = 10 ** 18;
         uint256 amountOut = 1847751195973566072891;
@@ -280,13 +201,14 @@ contract UniswapV2ExecutorTest is Test, Constants {
             uint8(ExecutorTransferMethods.TransferMethod.TRANSFERPERMIT2)
         );
 
-
         deal(WETH_ADDR, ALICE, amountIn);
         vm.startPrank(ALICE);
         (
             IAllowanceTransfer.PermitSingle memory permitSingle,
             bytes memory signature
-        ) = handlePermit2Approval(WETH_ADDR, amountIn);
+        ) = handlePermit2Approval(
+            WETH_ADDR, address(uniswapV2Exposed), amountIn
+        );
 
         // Assume the permit2.approve method will be called from the TychoRouter
         // Replicate this secnario in this test.