From 3e0129f0d265eae2283d58bf0fcc78ea0f21a085 Mon Sep 17 00:00:00 2001
From: Mikhail Melnik <by.zumzoom@gmail.com>
Date: Tue, 19 Nov 2024 17:42:00 +0400
Subject: [PATCH 01/17] upgrade FeeTaker

---
 contracts/extensions/AmountGetterBase.sol    |  71 ++++++++
 contracts/extensions/AmountGetterWithFee.sol | 113 ++++++++++++
 contracts/extensions/FeeTaker.sol            | 172 ++++++-------------
 test/FeeTaker.js                             |  74 ++++----
 4 files changed, 277 insertions(+), 153 deletions(-)
 create mode 100644 contracts/extensions/AmountGetterBase.sol
 create mode 100644 contracts/extensions/AmountGetterWithFee.sol

diff --git a/contracts/extensions/AmountGetterBase.sol b/contracts/extensions/AmountGetterBase.sol
new file mode 100644
index 00000000..8206ee09
--- /dev/null
+++ b/contracts/extensions/AmountGetterBase.sol
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity 0.8.23;
+
+import { Math } from "@openzeppelin/contracts/utils/math/Math.sol";
+
+import { IAmountGetter } from "../interfaces/IAmountGetter.sol";
+import { IOrderMixin } from "../interfaces/IOrderMixin.sol";
+
+/// @title Base price getter contract that either calls external getter or applies linear formula
+contract AmountGetterBase is IAmountGetter {
+    function getMakingAmount(
+        IOrderMixin.Order calldata order,
+        bytes calldata extension,
+        bytes32 orderHash,
+        address taker,
+        uint256 takingAmount,
+        uint256 remainingMakingAmount,
+        bytes calldata extraData
+    ) external view returns (uint256) {
+        return _getMakingAmount(order, extension, orderHash, taker, takingAmount, remainingMakingAmount, extraData);
+    }
+
+    function getTakingAmount(
+        IOrderMixin.Order calldata order,
+        bytes calldata extension,
+        bytes32 orderHash,
+        address taker,
+        uint256 makingAmount,
+        uint256 remainingMakingAmount,
+        bytes calldata extraData
+    ) external view returns (uint256) {
+        return _getTakingAmount(order, extension, orderHash, taker, makingAmount, remainingMakingAmount, extraData);
+    }
+
+    function _getMakingAmount(
+        IOrderMixin.Order calldata order,
+        bytes calldata extension,
+        bytes32 orderHash,
+        address taker,
+        uint256 takingAmount,
+        uint256 remainingMakingAmount,
+        bytes calldata extraData
+    ) internal view virtual returns (uint256) {
+        if (extraData.length >= 20) {
+            return IAmountGetter(address(bytes20(extraData))).getMakingAmount(
+                order, extension, orderHash, taker, takingAmount, remainingMakingAmount, extraData[20:]
+            );
+        } else {
+            return Math.mulDiv(order.makingAmount, takingAmount, order.takingAmount);
+        }
+    }
+
+    function _getTakingAmount(
+        IOrderMixin.Order calldata order,
+        bytes calldata extension,
+        bytes32 orderHash,
+        address taker,
+        uint256 makingAmount,
+        uint256 remainingMakingAmount,
+        bytes calldata extraData
+    ) internal view virtual returns (uint256) {
+        if (extraData.length >= 20) {
+            return IAmountGetter(address(bytes20(extraData))).getTakingAmount(
+                order, extension, orderHash, taker, makingAmount, remainingMakingAmount, extraData[20:]
+            );
+        } else {
+            return Math.mulDiv(order.takingAmount, makingAmount, order.makingAmount, Math.Rounding.Ceil);
+        }
+    }
+}
diff --git a/contracts/extensions/AmountGetterWithFee.sol b/contracts/extensions/AmountGetterWithFee.sol
new file mode 100644
index 00000000..d8daa84b
--- /dev/null
+++ b/contracts/extensions/AmountGetterWithFee.sol
@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: MIT
+
+pragma solidity 0.8.23;
+
+import { Math } from "@openzeppelin/contracts/utils/math/Math.sol";
+
+import { IOrderMixin } from "../interfaces/IOrderMixin.sol";
+import { AmountGetterBase } from "./AmountGetterBase.sol";
+
+/// @title Price getter contract that adds fee calculation
+contract AmountGetterWithFee is AmountGetterBase {
+    /// @dev Allows fees in range [1e-5, 0.65535]
+    uint256 internal constant _FEE_BASE = 1e5;
+    uint256 internal constant _DISCOUNT_BASE = 100;
+
+    /**
+     * @dev Calculates makingAmount with fee.
+     */
+    function _getMakingAmount(
+        IOrderMixin.Order calldata order,
+        bytes calldata extension,
+        bytes32 orderHash,
+        address taker,
+        uint256 takingAmount,
+        uint256 remainingMakingAmount,
+        bytes calldata extraData
+    ) internal view override returns (uint256) {
+        unchecked {
+            (, uint256 integratorFee, uint256 resolverFee, bytes calldata tail) = _parseFeeData(extraData, taker, _isWhitelistedGetterImpl);
+            return Math.mulDiv(
+                super._getMakingAmount(order, extension, orderHash, taker, takingAmount, remainingMakingAmount, tail),
+                _FEE_BASE,
+                _FEE_BASE + integratorFee + resolverFee
+            );
+        }
+    }
+
+    /**
+     * @dev Calculates takingAmount with fee.
+     */
+    function _getTakingAmount(
+        IOrderMixin.Order calldata order,
+        bytes calldata extension,
+        bytes32 orderHash,
+        address taker,
+        uint256 makingAmount,
+        uint256 remainingMakingAmount,
+        bytes calldata extraData
+    ) internal view override returns (uint256) {
+        unchecked {
+            (, uint256 integratorFee, uint256 resolverFee, bytes calldata tail) = _parseFeeData(extraData, taker, _isWhitelistedGetterImpl);
+            return Math.mulDiv(
+                super._getTakingAmount(order, extension, orderHash, taker, makingAmount, remainingMakingAmount, tail),
+                _FEE_BASE + integratorFee + resolverFee,
+                _FEE_BASE,
+                Math.Rounding.Ceil
+            );
+        }
+    }
+
+    /**
+     * @dev `extraData` consists of:
+     * 2 bytes — integrator fee percentage (in 1e5)
+     * 2 bytes — resolver fee percentage (in 1e5)
+     * 1 byte - whitelist discount numerator (in 1e2)
+     * bytes — whitelist structure determined by `_isWhitelisted` implementation
+     * bytes — custom data (optional)
+     * @param _isWhitelisted internal function to parse and check whitelist
+     */
+    function _parseFeeData(
+        bytes calldata extraData,
+        address taker,
+        function (bytes calldata, address) internal view returns (bool, bytes calldata) _isWhitelisted
+    ) internal view returns (bool isWhitelisted, uint256 integratorFee, uint256 resolverFee, bytes calldata tail) {
+        unchecked {
+            integratorFee = uint256(uint16(bytes2(extraData)));
+            resolverFee = uint256(uint16(bytes2(extraData[2:])));
+            uint256 whitelistDiscountNumerator = uint256(uint8(bytes1(extraData[4:])));
+            (isWhitelisted, tail) = _isWhitelisted(extraData[5:], taker);
+            if (isWhitelisted) {
+                resolverFee = resolverFee * whitelistDiscountNumerator / _DISCOUNT_BASE;
+            }
+        }
+    }
+
+    /**
+     * @dev Validates whether the taker is whitelisted.
+     * @param whitelistData Whitelist data is a tightly packed struct of the following format:
+     * ```
+     * 1 byte - size of the whitelist
+     * (bytes10)[N] whiteliested addresses;
+     * ```
+     * Only 10 lowest bytes of the address are used for comparison.
+     * @param taker The taker address to check.
+     * @return isWhitelisted Whether the taker is whitelisted.
+     * @return tail Remaining calldata.
+     */
+    function _isWhitelistedGetterImpl(bytes calldata whitelistData, address taker) internal pure returns (bool isWhitelisted, bytes calldata tail) {
+        unchecked {
+            uint80 maskedTakerAddress = uint80(uint160(taker));
+            uint256 size = uint8(whitelistData[0]);
+            bytes calldata whitelist = whitelistData[1:1 + 10 * size];
+            tail = whitelistData[1 + 10 * size:];
+            for (uint256 i = 0; i < size; i++) {
+                uint80 whitelistedAddress = uint80(bytes10(whitelist[:10]));
+                if (maskedTakerAddress == whitelistedAddress) {
+                    return (true, tail);
+                }
+                whitelist = whitelist[10:];
+            }
+        }
+    }
+}
diff --git a/contracts/extensions/FeeTaker.sol b/contracts/extensions/FeeTaker.sol
index 69c240c0..18445a13 100644
--- a/contracts/extensions/FeeTaker.sol
+++ b/contracts/extensions/FeeTaker.sol
@@ -9,33 +9,39 @@ import { IERC20 } from "@openzeppelin/contracts/token/ERC20/IERC20.sol";
 import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
 import { Math } from "@openzeppelin/contracts/utils/math/Math.sol";
 
-import { IAmountGetter } from "../interfaces/IAmountGetter.sol";
 import { IOrderMixin } from "../interfaces/IOrderMixin.sol";
 import { IPostInteraction } from "../interfaces/IPostInteraction.sol";
 import { MakerTraits, MakerTraitsLib } from "../libraries/MakerTraitsLib.sol";
+import { AmountGetterWithFee } from "./AmountGetterWithFee.sol";
 
 /// @title Helper contract that adds feature of collecting fee in takerAsset
-contract FeeTaker is IPostInteraction, IAmountGetter, Ownable {
+contract FeeTaker is IPostInteraction, AmountGetterWithFee, Ownable {
     using AddressLib for Address;
     using SafeERC20 for IERC20;
     using UniERC20 for IERC20;
     using MakerTraitsLib for MakerTraits;
 
+    bytes1 private constant _CUSTOM_RECEIVER_FLAG = 0x01;
+
     /**
      * @dev The caller is not the limit order protocol contract.
      */
     error OnlyLimitOrderProtocol();
 
+    /**
+     * @dev The taker is not whitelisted and does not have access token.
+     */
+    error OnlyWhitelistOrAccessToken();
+
     /**
      * @dev Eth transfer failed. The target fallback may have reverted.
      */
     error EthTransferFailed();
 
-    /// @dev Allows fees in range [1e-5, 0.65535]
-    uint256 internal constant _FEE_BASE = 1e5;
-
     address private immutable _LIMIT_ORDER_PROTOCOL;
     address private immutable _WETH;
+    /// @notice Contract address whose tokens allow filling limit orders with a fee for resolvers that are outside the whitelist
+    IERC20 private immutable _ACCESS_TOKEN;
 
     /// @dev Modifier to check if the caller is the limit order protocol contract.
     modifier onlyLimitOrderProtocol {
@@ -46,10 +52,14 @@ contract FeeTaker is IPostInteraction, IAmountGetter, Ownable {
     /**
      * @notice Initializes the contract.
      * @param limitOrderProtocol The limit order protocol contract.
+     * @param accessToken Contract address whose tokens allow filling limit orders with a fee for resolvers that are outside the whitelist.
+     * @param weth The WETH address.
+     * @param owner The owner of the contract.
      */
-    constructor(address limitOrderProtocol, address weth, address owner) Ownable(owner) {
+    constructor(address limitOrderProtocol, IERC20 accessToken, address weth, address owner) Ownable(owner) {
         _LIMIT_ORDER_PROTOCOL = limitOrderProtocol;
         _WETH = weth;
+        _ACCESS_TOKEN = accessToken;
     }
 
     /**
@@ -57,101 +67,66 @@ contract FeeTaker is IPostInteraction, IAmountGetter, Ownable {
      */
     receive() external payable {}
 
-    /**
-     * @dev Calculate makingAmount with fee.
-     * `extraData` consists of:
-     * 2 bytes — integrator fee percentage (in 1e5)
-     * 2 bytes — resolver fee percentage (in 1e5)
-     * 1 byte - taker whitelist size
-     * (bytes10)[N] — taker whitelist
-     */
-    function getMakingAmount(
+    function postInteraction(
         IOrderMixin.Order calldata order,
         bytes calldata extension,
         bytes32 orderHash,
         address taker,
+        uint256 makingAmount,
         uint256 takingAmount,
         uint256 remainingMakingAmount,
         bytes calldata extraData
-    ) external view returns (uint256 calculatedMakingAmount) {
-        unchecked {
-            (uint256 integratorFee, uint256 resolverFee, bytes calldata tail) = _parseFeeData(extraData, taker);
-            if (tail.length > 20) {
-                calculatedMakingAmount = IAmountGetter(address(bytes20(tail))).getMakingAmount(
-                    order, extension, orderHash, taker, takingAmount, remainingMakingAmount, tail[20:]
-                );
-            } else {
-                calculatedMakingAmount = order.makingAmount;
-            }
-            calculatedMakingAmount = Math.mulDiv(calculatedMakingAmount, _FEE_BASE, _FEE_BASE + integratorFee + resolverFee, Math.Rounding.Floor);
-            return Math.mulDiv(calculatedMakingAmount, takingAmount, order.takingAmount, Math.Rounding.Floor);
-        }
+    ) external onlyLimitOrderProtocol {
+        _postInteraction(order, extension, orderHash, taker, makingAmount, takingAmount, remainingMakingAmount, extraData);
     }
 
     /**
-     * @dev Calculate takingAmount with fee.
-     * `extraData` consists of:
-     * 2 bytes — integrator fee percentage (in 1e5)
-     * 2 bytes — resolver fee percentage (in 1e5)
-     * 1 byte - taker whitelist size
-     * (bytes10)[N] — taker whitelist
+     * @notice Retrieves funds accidently sent directly to the contract address
+     * @param token ERC20 token to retrieve
+     * @param amount amount to retrieve
      */
-    function getTakingAmount(
-        IOrderMixin.Order calldata order,
-        bytes calldata extension,
-        bytes32 orderHash,
-        address taker,
-        uint256 makingAmount,
-        uint256 remainingMakingAmount,
-        bytes calldata extraData
-    ) external view returns (uint256 calculatedTakingAmount) {
-        unchecked {
-            (uint256 integratorFee, uint256 resolverFee, bytes calldata tail) = _parseFeeData(extraData, taker);
-            if (tail.length > 20) {
-                calculatedTakingAmount = IAmountGetter(address(bytes20(tail))).getTakingAmount(
-                    order, extension, orderHash, taker, makingAmount, remainingMakingAmount, tail[20:]
-                );
-            } else {
-                calculatedTakingAmount = order.takingAmount;
-            }
-            calculatedTakingAmount = Math.mulDiv(calculatedTakingAmount, _FEE_BASE + integratorFee + resolverFee, _FEE_BASE, Math.Rounding.Ceil);
-            return Math.mulDiv(calculatedTakingAmount, makingAmount, order.makingAmount, Math.Rounding.Ceil);
-        }
+    function rescueFunds(IERC20 token, uint256 amount) external onlyOwner {
+        token.uniTransfer(payable(msg.sender), amount);
     }
 
     /**
      * @notice See {IPostInteraction-postInteraction}.
      * @dev Takes the fee in taking tokens and transfers the rest to the maker.
      * `extraData` consists of:
-     * 2 bytes — integrator fee percentage (in 1e5)
-     * 2 bytes — resolver fee percentage (in 1e5)
-     * 1 byte - taker whitelist size
-     * (bytes10)[N] — taker whitelist
+     * 1 byte - flags
      * 20 bytes — fee recipient
      * 20 bytes — receiver of taking tokens (optional, if not set, maker is used)
+     * 2 bytes — integrator fee percentage (in 1e5)
+     * 2 bytes — resolver fee percentage (in 1e5)
+     * bytes — whitelist structure determined by `_isWhitelistedPostInteractionImpl` implementation
+     * bytes — custom data to call extra postInteraction (optional)
      */
-    function postInteraction(
+    function _postInteraction(
         IOrderMixin.Order calldata order,
-        bytes calldata /* extension */,
-        bytes32 /* orderHash */,
+        bytes calldata extension,
+        bytes32 orderHash,
         address taker,
-        uint256 /* makingAmount */,
+        uint256 makingAmount,
         uint256 takingAmount,
-        uint256 /* remainingMakingAmount */,
+        uint256 remainingMakingAmount,
         bytes calldata extraData
-    ) external onlyLimitOrderProtocol {
+    ) internal virtual {
         unchecked {
-            (uint256 integratorFee, uint256 resolverFee, bytes calldata tail) = _parseFeeData(extraData, taker);
-            address feeRecipient = address(bytes20(tail));
-            tail = tail[20:];
-            uint256 denominator = _FEE_BASE + integratorFee + resolverFee;
-            // fee is calculated as a sum of separate fees to limit rounding errors
-            uint256 fee = Math.mulDiv(takingAmount, integratorFee, denominator) + Math.mulDiv(takingAmount, resolverFee, denominator);
+            bool customReceiver = extraData[0] & _CUSTOM_RECEIVER_FLAG == _CUSTOM_RECEIVER_FLAG;
+            address feeRecipient = address(bytes20(extraData[1:21]));
+            extraData = extraData[21:];
 
             address receiver = order.maker.get();
-            if (tail.length > 0) {
-                receiver = address(bytes20(tail));
+            if (customReceiver) {
+                receiver = address(bytes20(extraData));
+                extraData = extraData[20:];
             }
+            (bool isWhitelisted, uint256 integratorFee, uint256 resolverFee, bytes calldata tail) = _parseFeeData(extraData, taker, _isWhitelistedPostInteractionImpl);
+            if (!isWhitelisted && _ACCESS_TOKEN.balanceOf(taker) == 0) revert OnlyWhitelistOrAccessToken();
+
+            uint256 denominator = _FEE_BASE + integratorFee + resolverFee;
+            // fee is calculated as a sum of separate fees to limit rounding errors
+            uint256 fee = Math.mulDiv(takingAmount, integratorFee, denominator) + Math.mulDiv(takingAmount, resolverFee, denominator);
 
             if (order.takerAsset.get() == address(_WETH) && order.makerTraits.unwrapWeth()) {
                 if (fee > 0) {
@@ -164,16 +139,19 @@ contract FeeTaker is IPostInteraction, IAmountGetter, Ownable {
                 }
                 IERC20(order.takerAsset.get()).safeTransfer(receiver, takingAmount - fee);
             }
+
+            if (tail.length >= 20) {
+                IPostInteraction(address(bytes20(tail))).postInteraction(order, extension, orderHash, taker, makingAmount, takingAmount, remainingMakingAmount, tail[20:]);
+            }
         }
     }
 
     /**
-     * @notice Retrieves funds accidently sent directly to the contract address
-     * @param token ERC20 token to retrieve
-     * @param amount amount to retrieve
+     * @dev Parses fee data from `extraData`.
+     * Override this function if whitelist structure in postInteraction is different from getters.
      */
-    function rescueFunds(IERC20 token, uint256 amount) external onlyOwner {
-        token.uniTransfer(payable(msg.sender), amount);
+    function _isWhitelistedPostInteractionImpl(bytes calldata whitelistData, address taker) internal view virtual returns (bool isWhitelisted, bytes calldata tail) {
+        return _isWhitelistedGetterImpl(whitelistData, taker);
     }
 
     function _sendEth(address target, uint256 amount) private {
@@ -182,42 +160,4 @@ contract FeeTaker is IPostInteraction, IAmountGetter, Ownable {
             revert EthTransferFailed();
         }
     }
-
-    /**
-     * @dev Validates whether the resolver is whitelisted.
-     * @param whitelist Whitelist is tightly packed struct of the following format:
-     * ```
-     * (bytes10)[N] resolversAddresses;
-     * ```
-     * Only 10 lowest bytes of the resolver address are used for comparison.
-     * @param resolver The resolver to check.
-     * @return Whether the resolver is whitelisted.
-     */
-    function _isWhitelisted(bytes calldata whitelist, address resolver) private pure returns (bool) {
-        unchecked {
-            uint80 maskedResolverAddress = uint80(uint160(resolver));
-            uint256 size = whitelist.length / 10;
-            for (uint256 i = 0; i < size; i++) {
-                uint80 whitelistedAddress = uint80(bytes10(whitelist[:10]));
-                if (maskedResolverAddress == whitelistedAddress) {
-                    return true;
-                }
-                whitelist = whitelist[10:];
-            }
-            return false;
-        }
-    }
-
-    function _parseFeeData(bytes calldata extraData, address taker) private pure returns (uint256 integratorFee, uint256 resolverFee, bytes calldata tail) {
-        unchecked {
-            integratorFee = uint256(uint16(bytes2(extraData)));
-            resolverFee = uint256(uint16(bytes2(extraData[2:])));
-            uint256 whitelistEnd = 5 + 10 * uint256(uint8(extraData[4]));
-            bytes calldata whitelist = extraData[5:whitelistEnd];
-            if (!_isWhitelisted(whitelist, taker)) {
-                resolverFee *= 2;
-            }
-            tail = extraData[whitelistEnd:];
-        }
-    }
 }
diff --git a/test/FeeTaker.js b/test/FeeTaker.js
index cdf5c942..63dbb45f 100644
--- a/test/FeeTaker.js
+++ b/test/FeeTaker.js
@@ -30,7 +30,7 @@ describe('FeeTaker', function () {
         await inch.connect(addr1).approve(swap, ether('1000000'));
 
         const FeeTaker = await ethers.getContractFactory('FeeTaker');
-        const feeTaker = await FeeTaker.deploy(swap, weth, addr);
+        const feeTaker = await FeeTaker.deploy(swap, inch, weth, addr);
 
         return { dai, weth, inch, swap, chainId, feeTaker };
     };
@@ -54,8 +54,8 @@ describe('FeeTaker', function () {
             },
             {
                 postInteraction: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'bytes1', 'address'],
-                    [await feeTaker.getAddress(), fee, fee, '0x00', feeRecipient],
+                    ['address', 'bytes1', 'address', 'uint16', 'uint16', 'uint8', 'bytes1'],
+                    [await feeTaker.getAddress(), '0x00', feeRecipient, fee, fee, 50, '0x00'],
                 ),
             },
         );
@@ -90,8 +90,8 @@ describe('FeeTaker', function () {
             },
             {
                 postInteraction: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'bytes1', 'address', 'address'],
-                    [await feeTaker.getAddress(), fee, fee, '0x00', feeRecipient, makerReceiver],
+                    ['address', 'bytes1', 'address', 'address', 'uint16', 'uint16', 'uint8', 'bytes1'],
+                    [await feeTaker.getAddress(), '0x01', feeRecipient, makerReceiver, fee, fee, 50, '0x00'],
                 ),
             },
         );
@@ -132,16 +132,16 @@ describe('FeeTaker', function () {
                 // * 1 byte - taker whitelist size
                 // * (bytes10)[N] — taker whitelist
                 postInteraction: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'bytes1', 'bytes', 'address'],
-                    [await feeTaker.getAddress(), integratorFee, resolverFee, '0x0a', whitelist, feeRecipient],
+                    ['address', 'bytes1', 'address', 'uint16', 'uint16', 'uint8', 'bytes1', 'bytes'],
+                    [await feeTaker.getAddress(), '0x00', feeRecipient, integratorFee, resolverFee, 50, '0x0a', whitelist],
                 ),
                 makingAmountData: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'bytes1', 'bytes'],
-                    [await feeTaker.getAddress(), integratorFee, resolverFee, '0x0a', whitelist],
+                    ['address', 'uint16', 'uint16', 'uint8', 'bytes1', 'bytes'],
+                    [await feeTaker.getAddress(), integratorFee, resolverFee, 50, '0x0a', whitelist],
                 ),
                 takingAmountData: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'bytes1', 'bytes'],
-                    [await feeTaker.getAddress(), integratorFee, resolverFee, '0x0a', whitelist],
+                    ['address', 'uint16', 'uint16', 'uint8', 'bytes1', 'bytes'],
+                    [await feeTaker.getAddress(), integratorFee, resolverFee, 50, '0x0a', whitelist],
                 ),
             },
         );
@@ -154,7 +154,7 @@ describe('FeeTaker', function () {
         const fillTx = swap.fillOrderArgs(order, r, vs, makingAmount, takerTraits.traits, takerTraits.args);
         console.log(`GasUsed: ${(await (await fillTx).wait()).gasUsed.toString()}`);
 
-        const feeCalculated = takingAmount * (integratorFee + resolverFee) / BigInt(1e5);
+        const feeCalculated = takingAmount * (integratorFee + resolverFee / 2n) / BigInt(1e5);
         await expect(fillTx).to.changeTokenBalances(dai, [addr, addr1], [makingAmount, -makingAmount]);
         await expect(fillTx).to.changeTokenBalances(weth, [addr, addr1, addr2], [-takingAmount - feeCalculated, takingAmount, feeCalculated]);
     });
@@ -185,16 +185,16 @@ describe('FeeTaker', function () {
                 // * 1 byte - taker whitelist size
                 // * (bytes10)[N] — taker whitelist
                 postInteraction: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'bytes1', 'bytes', 'address'],
-                    [await feeTaker.getAddress(), integratorFee, resolverFee, '0x0a', whitelist, feeRecipient],
+                    ['address', 'bytes1', 'address', 'uint16', 'uint16', 'uint8', 'bytes1', 'bytes'],
+                    [await feeTaker.getAddress(), '0x00', feeRecipient, integratorFee, resolverFee, 50, '0x0a', whitelist],
                 ),
                 makingAmountData: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'bytes1', 'bytes'],
-                    [await feeTaker.getAddress(), integratorFee, resolverFee, '0x0a', whitelist],
+                    ['address', 'uint16', 'uint16', 'uint8', 'bytes1', 'bytes'],
+                    [await feeTaker.getAddress(), integratorFee, resolverFee, 50, '0x0a', whitelist],
                 ),
                 takingAmountData: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'bytes1', 'bytes'],
-                    [await feeTaker.getAddress(), integratorFee, resolverFee, '0x0a', whitelist],
+                    ['address', 'uint16', 'uint16', 'uint8', 'bytes1', 'bytes'],
+                    [await feeTaker.getAddress(), integratorFee, resolverFee, 50, '0x0a', whitelist],
                 ),
             },
         );
@@ -207,7 +207,7 @@ describe('FeeTaker', function () {
         const fillTx = swap.fillOrderArgs(order, r, vs, makingAmount, takerTraits.traits, takerTraits.args);
         console.log(`GasUsed: ${(await (await fillTx).wait()).gasUsed.toString()}`);
 
-        const feeCalculated = takingAmount * (integratorFee + resolverFee + resolverFee) / BigInt(1e5);
+        const feeCalculated = takingAmount * (integratorFee + resolverFee) / BigInt(1e5);
         await expect(fillTx).to.changeTokenBalances(dai, [addr, addr1], [makingAmount, -makingAmount]);
         await expect(fillTx).to.changeTokenBalances(weth,
             [addr, addr1, addr2],
@@ -236,16 +236,16 @@ describe('FeeTaker', function () {
             },
             {
                 postInteraction: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'bytes1', 'address', 'address'],
-                    [await feeTaker.getAddress(), fee, 0, '0x00', feeRecipient, makerReceiver],
+                    ['address', 'bytes1', 'address', 'address', 'uint16', 'uint16', 'uint8', 'bytes1'],
+                    [await feeTaker.getAddress(), '0x01', feeRecipient, makerReceiver, fee, 0, 50, '0x00'],
                 ),
                 makingAmountData: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'bytes1'],
-                    [await feeTaker.getAddress(), fee, 0, '0x00'],
+                    ['address', 'uint16', 'uint16', 'uint8', 'bytes1'],
+                    [await feeTaker.getAddress(), fee, 0, 50, '0x00'],
                 ),
                 takingAmountData: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'bytes1'],
-                    [await feeTaker.getAddress(), fee, 0, '0x00'],
+                    ['address', 'uint16', 'uint16', 'uint8', 'bytes1'],
+                    [await feeTaker.getAddress(), fee, 0, 50, '0x00'],
                 ),
             },
         );
@@ -281,16 +281,16 @@ describe('FeeTaker', function () {
             },
             {
                 postInteraction: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'bytes1', 'address'],
-                    [await feeTaker.getAddress(), fee, 0, '0x00', feeRecipient],
+                    ['address', 'bytes1', 'address', 'uint16', 'uint16', 'uint8', 'bytes1'],
+                    [await feeTaker.getAddress(), '0x00', feeRecipient, fee, 0, 50, '0x00'],
                 ),
                 makingAmountData: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'bytes1'],
-                    [await feeTaker.getAddress(), fee, 0, '0x00'],
+                    ['address', 'uint16', 'uint16', 'uint8', 'bytes1'],
+                    [await feeTaker.getAddress(), fee, 0, 50, '0x00'],
                 ),
                 takingAmountData: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'bytes1'],
-                    [await feeTaker.getAddress(), fee, 0, '0x00'],
+                    ['address', 'uint16', 'uint16', 'uint8', 'bytes1'],
+                    [await feeTaker.getAddress(), fee, 0, 50, '0x00'],
                 ),
             },
         );
@@ -328,16 +328,16 @@ describe('FeeTaker', function () {
             },
             {
                 postInteraction: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'bytes1', 'address', 'address'],
-                    [await feeTaker.getAddress(), fee, 0, '0x00', feeRecipient, makerReceiver],
+                    ['address', 'bytes1', 'address', 'address', 'uint16', 'uint16', 'uint8', 'bytes1'],
+                    [await feeTaker.getAddress(), '0x01', feeRecipient, makerReceiver, fee, 0, 50, '0x00'],
                 ),
                 makingAmountData: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'bytes1'],
-                    [await feeTaker.getAddress(), fee, 0, '0x00'],
+                    ['address', 'uint16', 'uint16', 'uint8', 'bytes1'],
+                    [await feeTaker.getAddress(), fee, 0, 50, '0x00'],
                 ),
                 takingAmountData: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'bytes1'],
-                    [await feeTaker.getAddress(), fee, 0, '0x00'],
+                    ['address', 'uint16', 'uint16', 'uint8', 'bytes1'],
+                    [await feeTaker.getAddress(), fee, 0, 50, '0x00'],
                 ),
             },
         );

From 93e3fa26cd72e0eedb2d8523647910489b806f69 Mon Sep 17 00:00:00 2001
From: Mikhail Melnik <by.zumzoom@gmail.com>
Date: Tue, 19 Nov 2024 17:47:47 +0400
Subject: [PATCH 02/17] fix package

---
 package.json | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/package.json b/package.json
index 727ddc0c..3ccbf404 100644
--- a/package.json
+++ b/package.json
@@ -8,11 +8,7 @@
   },
   "license": "MIT",
   "files": [
-    "contracts/*.sol",
-    "contracts/helpers",
-    "contracts/interfaces",
-    "contracts/libraries",
-    "contracts/mocks",
+    "contracts",
     "test/helpers"
   ],
   "dependencies": {

From ebd6934e157405a6cd81f08dd96df41291dd69ef Mon Sep 17 00:00:00 2001
From: Mikhail Melnik <by.zumzoom@gmail.com>
Date: Tue, 19 Nov 2024 17:47:55 +0400
Subject: [PATCH 03/17] bump version

---
 package.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/package.json b/package.json
index 3ccbf404..119cd79c 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@1inch/limit-order-protocol-contract",
-  "version": "4.1.1",
+  "version": "4.2.0",
   "description": "1inch Limit Order Protocol",
   "repository": {
     "type": "git",

From fec23799007523be80eabc2341a0c3159b479323 Mon Sep 17 00:00:00 2001
From: Mikhail Melnik <by.zumzoom@gmail.com>
Date: Tue, 19 Nov 2024 17:56:49 +0400
Subject: [PATCH 04/17] fix

---
 contracts/extensions/AmountGetterWithFee.sol | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/contracts/extensions/AmountGetterWithFee.sol b/contracts/extensions/AmountGetterWithFee.sol
index d8daa84b..b8f283e5 100644
--- a/contracts/extensions/AmountGetterWithFee.sol
+++ b/contracts/extensions/AmountGetterWithFee.sol
@@ -24,7 +24,7 @@ contract AmountGetterWithFee is AmountGetterBase {
         uint256 takingAmount,
         uint256 remainingMakingAmount,
         bytes calldata extraData
-    ) internal view override returns (uint256) {
+    ) internal view virtual override returns (uint256) {
         unchecked {
             (, uint256 integratorFee, uint256 resolverFee, bytes calldata tail) = _parseFeeData(extraData, taker, _isWhitelistedGetterImpl);
             return Math.mulDiv(
@@ -46,7 +46,7 @@ contract AmountGetterWithFee is AmountGetterBase {
         uint256 makingAmount,
         uint256 remainingMakingAmount,
         bytes calldata extraData
-    ) internal view override returns (uint256) {
+    ) internal view virtual override returns (uint256) {
         unchecked {
             (, uint256 integratorFee, uint256 resolverFee, bytes calldata tail) = _parseFeeData(extraData, taker, _isWhitelistedGetterImpl);
             return Math.mulDiv(

From d721b327e847d74dd86cce399f806ba13b3c829a Mon Sep 17 00:00:00 2001
From: Mikhail Melnik <by.zumzoom@gmail.com>
Date: Wed, 20 Nov 2024 14:05:22 +0400
Subject: [PATCH 05/17] add feeTaker builder

---
 test/FeeTaker.js           | 152 ++++++++++++-------------------------
 test/helpers/orderUtils.js |  34 +++++++++
 2 files changed, 84 insertions(+), 102 deletions(-)

diff --git a/test/FeeTaker.js b/test/FeeTaker.js
index 63dbb45f..eb8b51a7 100644
--- a/test/FeeTaker.js
+++ b/test/FeeTaker.js
@@ -3,10 +3,10 @@ const { ethers } = hre;
 const { expect } = require('@1inch/solidity-utils');
 const { loadFixture } = require('@nomicfoundation/hardhat-network-helpers');
 const { deploySwapTokens } = require('./helpers/fixtures');
-const { buildOrder, buildTakerTraits, signOrder, buildMakerTraits } = require('./helpers/orderUtils');
+const { buildOrder, buildTakerTraits, signOrder, buildMakerTraits, buildFeeTakerExtensions } = require('./helpers/orderUtils');
 const { ether } = require('./helpers/utils');
 
-describe('FeeTaker', function () {
+describe.only('FeeTaker', function () {
     let addr, addr1, addr2, addr3;
     before(async function () {
         [addr, addr1, addr2, addr3] = await ethers.getSigners();
@@ -40,7 +40,6 @@ describe('FeeTaker', function () {
 
         const makingAmount = ether('300');
         const takingAmount = ether('0.3');
-        const fee = 0;
         const feeRecipient = addr2.address;
 
         const order = buildOrder(
@@ -52,12 +51,10 @@ describe('FeeTaker', function () {
                 makingAmount,
                 takingAmount,
             },
-            {
-                postInteraction: ethers.solidityPacked(
-                    ['address', 'bytes1', 'address', 'uint16', 'uint16', 'uint8', 'bytes1'],
-                    [await feeTaker.getAddress(), '0x00', feeRecipient, fee, fee, 50, '0x00'],
-                ),
-            },
+            buildFeeTakerExtensions({
+                feeTaker: await feeTaker.getAddress(),
+                feeRecipient,
+            }),
         );
 
         const { r, yParityAndS: vs } = ethers.Signature.from(await signOrder(order, chainId, await swap.getAddress(), addr1));
@@ -75,7 +72,6 @@ describe('FeeTaker', function () {
 
         const makingAmount = ether('300');
         const takingAmount = ether('0.3');
-        const fee = 0;
         const feeRecipient = addr2.address;
         const makerReceiver = addr3.address;
 
@@ -88,12 +84,11 @@ describe('FeeTaker', function () {
                 makingAmount,
                 takingAmount,
             },
-            {
-                postInteraction: ethers.solidityPacked(
-                    ['address', 'bytes1', 'address', 'address', 'uint16', 'uint16', 'uint8', 'bytes1'],
-                    [await feeTaker.getAddress(), '0x01', feeRecipient, makerReceiver, fee, fee, 50, '0x00'],
-                ),
-            },
+            buildFeeTakerExtensions({
+                feeTaker: await feeTaker.getAddress(),
+                feeRecipient,
+                makerReceiver,
+            }),
         );
 
         const { r, yParityAndS: vs } = ethers.Signature.from(await signOrder(order, chainId, await swap.getAddress(), addr1));
@@ -125,25 +120,14 @@ describe('FeeTaker', function () {
                 makingAmount,
                 takingAmount,
             },
-            {
-                // * 2 bytes — integrator fee percentage (in 1e5)
-                // * 2 bytes — resolver fee percentage (in 1e5)
-                // * 20 bytes — fee recipient
-                // * 1 byte - taker whitelist size
-                // * (bytes10)[N] — taker whitelist
-                postInteraction: ethers.solidityPacked(
-                    ['address', 'bytes1', 'address', 'uint16', 'uint16', 'uint8', 'bytes1', 'bytes'],
-                    [await feeTaker.getAddress(), '0x00', feeRecipient, integratorFee, resolverFee, 50, '0x0a', whitelist],
-                ),
-                makingAmountData: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'uint8', 'bytes1', 'bytes'],
-                    [await feeTaker.getAddress(), integratorFee, resolverFee, 50, '0x0a', whitelist],
-                ),
-                takingAmountData: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'uint8', 'bytes1', 'bytes'],
-                    [await feeTaker.getAddress(), integratorFee, resolverFee, 50, '0x0a', whitelist],
-                ),
-            },
+            buildFeeTakerExtensions({
+                feeTaker: await feeTaker.getAddress(),
+                feeRecipient,
+                integratorFee,
+                resolverFee,
+                whitelistLength: 10,
+                whitelist,
+            }),
         );
 
         const { r, yParityAndS: vs } = ethers.Signature.from(await signOrder(order, chainId, await swap.getAddress(), addr1));
@@ -178,25 +162,14 @@ describe('FeeTaker', function () {
                 makingAmount,
                 takingAmount,
             },
-            {
-                // * 2 bytes — integrator fee percentage (in 1e5)
-                // * 2 bytes — resolver fee percentage (in 1e5)
-                // * 20 bytes — fee recipient
-                // * 1 byte - taker whitelist size
-                // * (bytes10)[N] — taker whitelist
-                postInteraction: ethers.solidityPacked(
-                    ['address', 'bytes1', 'address', 'uint16', 'uint16', 'uint8', 'bytes1', 'bytes'],
-                    [await feeTaker.getAddress(), '0x00', feeRecipient, integratorFee, resolverFee, 50, '0x0a', whitelist],
-                ),
-                makingAmountData: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'uint8', 'bytes1', 'bytes'],
-                    [await feeTaker.getAddress(), integratorFee, resolverFee, 50, '0x0a', whitelist],
-                ),
-                takingAmountData: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'uint8', 'bytes1', 'bytes'],
-                    [await feeTaker.getAddress(), integratorFee, resolverFee, 50, '0x0a', whitelist],
-                ),
-            },
+            buildFeeTakerExtensions({
+                feeTaker: await feeTaker.getAddress(),
+                feeRecipient,
+                integratorFee,
+                resolverFee,
+                whitelistLength: 10,
+                whitelist,
+            }),
         );
 
         const { r, yParityAndS: vs } = ethers.Signature.from(await signOrder(order, chainId, await swap.getAddress(), addr1));
@@ -220,8 +193,8 @@ describe('FeeTaker', function () {
 
         const makingAmount = ether('300');
         const takingAmount = ether('0.3');
-        const fee = BigInt(1e4);
-        const feeCalculated = takingAmount * fee / BigInt(1e5);
+        const integratorFee = BigInt(1e4);
+        const feeCalculated = takingAmount * integratorFee / BigInt(1e5);
         const feeRecipient = addr2.address;
         const makerReceiver = addr3.address;
 
@@ -234,20 +207,12 @@ describe('FeeTaker', function () {
                 makingAmount,
                 takingAmount,
             },
-            {
-                postInteraction: ethers.solidityPacked(
-                    ['address', 'bytes1', 'address', 'address', 'uint16', 'uint16', 'uint8', 'bytes1'],
-                    [await feeTaker.getAddress(), '0x01', feeRecipient, makerReceiver, fee, 0, 50, '0x00'],
-                ),
-                makingAmountData: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'uint8', 'bytes1'],
-                    [await feeTaker.getAddress(), fee, 0, 50, '0x00'],
-                ),
-                takingAmountData: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'uint8', 'bytes1'],
-                    [await feeTaker.getAddress(), fee, 0, 50, '0x00'],
-                ),
-            },
+            buildFeeTakerExtensions({
+                feeTaker: await feeTaker.getAddress(),
+                feeRecipient,
+                makerReceiver,
+                integratorFee,
+            }),
         );
 
         const { r, yParityAndS: vs } = ethers.Signature.from(await signOrder(order, chainId, await swap.getAddress(), addr1));
@@ -265,8 +230,8 @@ describe('FeeTaker', function () {
 
         const makingAmount = ether('300');
         const takingAmount = ether('0.3');
-        const fee = BigInt(1e4);
-        const feeCalculated = takingAmount * fee / BigInt(1e5);
+        const integratorFee = BigInt(1e4);
+        const feeCalculated = takingAmount * integratorFee / BigInt(1e5);
         const feeRecipient = addr2.address;
 
         const order = buildOrder(
@@ -279,20 +244,11 @@ describe('FeeTaker', function () {
                 takingAmount,
                 makerTraits: buildMakerTraits({ unwrapWeth: true }),
             },
-            {
-                postInteraction: ethers.solidityPacked(
-                    ['address', 'bytes1', 'address', 'uint16', 'uint16', 'uint8', 'bytes1'],
-                    [await feeTaker.getAddress(), '0x00', feeRecipient, fee, 0, 50, '0x00'],
-                ),
-                makingAmountData: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'uint8', 'bytes1'],
-                    [await feeTaker.getAddress(), fee, 0, 50, '0x00'],
-                ),
-                takingAmountData: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'uint8', 'bytes1'],
-                    [await feeTaker.getAddress(), fee, 0, 50, '0x00'],
-                ),
-            },
+            buildFeeTakerExtensions({
+                feeTaker: await feeTaker.getAddress(),
+                feeRecipient,
+                integratorFee,
+            }),
         );
 
         const { r, yParityAndS: vs } = ethers.Signature.from(await signOrder(order, chainId, await swap.getAddress(), addr1));
@@ -311,8 +267,8 @@ describe('FeeTaker', function () {
 
         const makingAmount = ether('300');
         const takingAmount = ether('0.3');
-        const fee = BigInt(1e4);
-        const feeCalculated = takingAmount * fee / BigInt(1e5);
+        const integratorFee = BigInt(1e4);
+        const feeCalculated = takingAmount * integratorFee / BigInt(1e5);
         const feeRecipient = addr2.address;
         const makerReceiver = addr3.address;
 
@@ -326,20 +282,12 @@ describe('FeeTaker', function () {
                 takingAmount,
                 makerTraits: buildMakerTraits({ unwrapWeth: true }),
             },
-            {
-                postInteraction: ethers.solidityPacked(
-                    ['address', 'bytes1', 'address', 'address', 'uint16', 'uint16', 'uint8', 'bytes1'],
-                    [await feeTaker.getAddress(), '0x01', feeRecipient, makerReceiver, fee, 0, 50, '0x00'],
-                ),
-                makingAmountData: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'uint8', 'bytes1'],
-                    [await feeTaker.getAddress(), fee, 0, 50, '0x00'],
-                ),
-                takingAmountData: ethers.solidityPacked(
-                    ['address', 'uint16', 'uint16', 'uint8', 'bytes1'],
-                    [await feeTaker.getAddress(), fee, 0, 50, '0x00'],
-                ),
-            },
+            buildFeeTakerExtensions({
+                feeTaker: await feeTaker.getAddress(),
+                feeRecipient,
+                makerReceiver,
+                integratorFee,
+            }),
         );
 
         const { r, yParityAndS: vs } = ethers.Signature.from(await signOrder(order, chainId, await swap.getAddress(), addr1));
diff --git a/test/helpers/orderUtils.js b/test/helpers/orderUtils.js
index 3483d503..5dd6d840 100644
--- a/test/helpers/orderUtils.js
+++ b/test/helpers/orderUtils.js
@@ -124,6 +124,39 @@ function buildMakerTraits ({
     ).toString(16).padStart(64, '0');
 }
 
+function buildFeeTakerExtensions({
+    feeTaker,
+    feeRecipient,
+    makerReceiver = undefined,
+    integratorFee = 0,
+    resolverFee = 0,
+    whitelistDiscount = 50,
+    whitelistLength = 0,
+    whitelist = '0x',
+    whitelistPostInteraction = whitelist,
+}) {
+    return {
+        makingAmountData: ethers.solidityPacked(
+            ['address', 'uint16', 'uint16', 'uint8', 'uint8', 'bytes'],
+            [feeTaker, integratorFee, resolverFee, whitelistDiscount, whitelistLength, whitelist],
+        ),
+        takingAmountData: ethers.solidityPacked(
+            ['address', 'uint16', 'uint16', 'uint8', 'uint8', 'bytes'],
+            [feeTaker, integratorFee, resolverFee, whitelistDiscount, whitelistLength, whitelist],
+        ),
+        postInteraction: ethers.solidityPacked(
+            ['address', 'bytes1', 'address'].concat(
+                makerReceiver ? ['address'] : [],
+                ['uint16', 'uint16', 'uint8', 'uint8', 'bytes'],
+            ),
+            [feeTaker, makerReceiver ? '0x01' : '0x00', feeRecipient].concat(
+                makerReceiver ? [makerReceiver] : [],
+                [integratorFee, resolverFee, whitelistDiscount, whitelistLength, whitelistPostInteraction],
+            ),
+        ),
+    }
+}
+
 function buildOrderRFQ (
     {
         maker,
@@ -276,6 +309,7 @@ module.exports = {
     buildTakerTraits,
     buildMakerTraits,
     buildMakerTraitsRFQ,
+    buildFeeTakerExtensions,
     buildOrder,
     buildOrderRFQ,
     buildOrderData,

From 06b7d79cb666cf9568bc460be7c3fb1fda6ba9d1 Mon Sep 17 00:00:00 2001
From: Mikhail Melnik <by.zumzoom@gmail.com>
Date: Wed, 20 Nov 2024 14:07:31 +0400
Subject: [PATCH 06/17] lint

---
 test/helpers/orderUtils.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/test/helpers/orderUtils.js b/test/helpers/orderUtils.js
index 5dd6d840..866ab137 100644
--- a/test/helpers/orderUtils.js
+++ b/test/helpers/orderUtils.js
@@ -124,7 +124,7 @@ function buildMakerTraits ({
     ).toString(16).padStart(64, '0');
 }
 
-function buildFeeTakerExtensions({
+function buildFeeTakerExtensions ({
     feeTaker,
     feeRecipient,
     makerReceiver = undefined,
@@ -154,7 +154,7 @@ function buildFeeTakerExtensions({
                 [integratorFee, resolverFee, whitelistDiscount, whitelistLength, whitelistPostInteraction],
             ),
         ),
-    }
+    };
 }
 
 function buildOrderRFQ (

From f6ba911358206504cb690dcfdb323104b62e92a9 Mon Sep 17 00:00:00 2001
From: Mikhail Melnik <by.zumzoom@gmail.com>
Date: Wed, 20 Nov 2024 14:09:59 +0400
Subject: [PATCH 07/17] support extra prefix for getters

---
 test/helpers/orderUtils.js | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/test/helpers/orderUtils.js b/test/helpers/orderUtils.js
index 866ab137..55a319f9 100644
--- a/test/helpers/orderUtils.js
+++ b/test/helpers/orderUtils.js
@@ -126,6 +126,7 @@ function buildMakerTraits ({
 
 function buildFeeTakerExtensions ({
     feeTaker,
+    getterExtraPrefix = '0x',
     feeRecipient,
     makerReceiver = undefined,
     integratorFee = 0,
@@ -137,12 +138,12 @@ function buildFeeTakerExtensions ({
 }) {
     return {
         makingAmountData: ethers.solidityPacked(
-            ['address', 'uint16', 'uint16', 'uint8', 'uint8', 'bytes'],
-            [feeTaker, integratorFee, resolverFee, whitelistDiscount, whitelistLength, whitelist],
+            ['address', 'bytes', 'uint16', 'uint16', 'uint8', 'uint8', 'bytes'],
+            [feeTaker, getterExtraPrefix, integratorFee, resolverFee, whitelistDiscount, whitelistLength, whitelist],
         ),
         takingAmountData: ethers.solidityPacked(
-            ['address', 'uint16', 'uint16', 'uint8', 'uint8', 'bytes'],
-            [feeTaker, integratorFee, resolverFee, whitelistDiscount, whitelistLength, whitelist],
+            ['address', 'bytes', 'uint16', 'uint16', 'uint8', 'uint8', 'bytes'],
+            [feeTaker, getterExtraPrefix, integratorFee, resolverFee, whitelistDiscount, whitelistLength, whitelist],
         ),
         postInteraction: ethers.solidityPacked(
             ['address', 'bytes1', 'address'].concat(

From 9135a1ecd8b1cd848ac111a6add4afa3eb2867d3 Mon Sep 17 00:00:00 2001
From: Mikhail Melnik <by.zumzoom@gmail.com>
Date: Wed, 20 Nov 2024 14:14:32 +0400
Subject: [PATCH 08/17] add default feeRecipient

---
 test/FeeTaker.js           | 14 +++++++-------
 test/helpers/orderUtils.js |  2 +-
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/test/FeeTaker.js b/test/FeeTaker.js
index eb8b51a7..e96186f7 100644
--- a/test/FeeTaker.js
+++ b/test/FeeTaker.js
@@ -64,7 +64,7 @@ describe.only('FeeTaker', function () {
         const fillTx = swap.fillOrderArgs(order, r, vs, makingAmount, takerTraits.traits, takerTraits.args);
         console.log(`GasUsed: ${(await (await fillTx).wait()).gasUsed.toString()}`);
         await expect(fillTx).to.changeTokenBalances(dai, [addr, addr1], [makingAmount, -makingAmount]);
-        await expect(fillTx).to.changeTokenBalances(weth, [addr, addr1, addr2], [-takingAmount, takingAmount, 0]);
+        await expect(fillTx).to.changeTokenBalances(weth, [addr, addr1, feeRecipient], [-takingAmount, takingAmount, 0]);
     });
 
     it('should send all tokens to the maker receiver with 0 fee', async function () {
@@ -98,7 +98,7 @@ describe.only('FeeTaker', function () {
         const fillTx = swap.fillOrderArgs(order, r, vs, makingAmount, takerTraits.traits, takerTraits.args);
         console.log(`GasUsed: ${(await (await fillTx).wait()).gasUsed.toString()}`);
         await expect(fillTx).to.changeTokenBalances(dai, [addr, addr1], [makingAmount, -makingAmount]);
-        await expect(fillTx).to.changeTokenBalances(weth, [addr, addr1, addr2, addr3], [-takingAmount, 0, 0, takingAmount]);
+        await expect(fillTx).to.changeTokenBalances(weth, [addr, addr1, feeRecipient, makerReceiver], [-takingAmount, 0, 0, takingAmount]);
     });
 
     it('should charge fee when in whitelist', async function () {
@@ -140,7 +140,7 @@ describe.only('FeeTaker', function () {
 
         const feeCalculated = takingAmount * (integratorFee + resolverFee / 2n) / BigInt(1e5);
         await expect(fillTx).to.changeTokenBalances(dai, [addr, addr1], [makingAmount, -makingAmount]);
-        await expect(fillTx).to.changeTokenBalances(weth, [addr, addr1, addr2], [-takingAmount - feeCalculated, takingAmount, feeCalculated]);
+        await expect(fillTx).to.changeTokenBalances(weth, [addr, addr1, feeRecipient], [-takingAmount - feeCalculated, takingAmount, feeCalculated]);
     });
 
     it('should charge fee when out of whitelist', async function () {
@@ -183,7 +183,7 @@ describe.only('FeeTaker', function () {
         const feeCalculated = takingAmount * (integratorFee + resolverFee) / BigInt(1e5);
         await expect(fillTx).to.changeTokenBalances(dai, [addr, addr1], [makingAmount, -makingAmount]);
         await expect(fillTx).to.changeTokenBalances(weth,
-            [addr, addr1, addr2],
+            [addr, addr1, feeRecipient],
             [-takingAmount - feeCalculated, takingAmount, feeCalculated],
         );
     });
@@ -222,7 +222,7 @@ describe.only('FeeTaker', function () {
         const fillTx = swap.fillOrderArgs(order, r, vs, makingAmount, takerTraits.traits, takerTraits.args);
         console.log(`GasUsed: ${(await (await fillTx).wait()).gasUsed.toString()}`);
         await expect(fillTx).to.changeTokenBalances(dai, [addr, addr1], [makingAmount, -makingAmount]);
-        await expect(fillTx).to.changeTokenBalances(weth, [addr, addr1, addr2, addr3], [-takingAmount - feeCalculated, 0, feeCalculated, takingAmount]);
+        await expect(fillTx).to.changeTokenBalances(weth, [addr, addr1, feeRecipient, makerReceiver], [-takingAmount - feeCalculated, 0, feeCalculated, takingAmount]);
     });
 
     it('should charge fee in eth', async function () {
@@ -259,7 +259,7 @@ describe.only('FeeTaker', function () {
         console.log(`GasUsed: ${(await (await fillTx).wait()).gasUsed.toString()}`);
         await expect(fillTx).to.changeTokenBalances(dai, [addr, addr1], [makingAmount, -makingAmount]);
         await expect(fillTx).to.changeTokenBalance(weth, addr, -takingAmount - feeCalculated);
-        await expect(fillTx).to.changeEtherBalances([addr1, addr2], [takingAmount, feeCalculated]);
+        await expect(fillTx).to.changeEtherBalances([addr1, feeRecipient], [takingAmount, feeCalculated]);
     });
 
     it('should charge fee in eth and send the rest to the maker receiver', async function () {
@@ -298,6 +298,6 @@ describe.only('FeeTaker', function () {
         console.log(`GasUsed: ${(await (await fillTx).wait()).gasUsed.toString()}`);
         await expect(fillTx).to.changeTokenBalances(dai, [addr, addr1], [makingAmount, -makingAmount]);
         await expect(fillTx).to.changeTokenBalance(weth, addr, -takingAmount - feeCalculated);
-        await expect(fillTx).to.changeEtherBalances([addr1, addr2, addr3], [0, feeCalculated, takingAmount]);
+        await expect(fillTx).to.changeEtherBalances([addr1, feeRecipient, makerReceiver], [0, feeCalculated, takingAmount]);
     });
 });
diff --git a/test/helpers/orderUtils.js b/test/helpers/orderUtils.js
index 55a319f9..c29958fb 100644
--- a/test/helpers/orderUtils.js
+++ b/test/helpers/orderUtils.js
@@ -127,7 +127,7 @@ function buildMakerTraits ({
 function buildFeeTakerExtensions ({
     feeTaker,
     getterExtraPrefix = '0x',
-    feeRecipient,
+    feeRecipient = constants.ZERO_ADDRESS,
     makerReceiver = undefined,
     integratorFee = 0,
     resolverFee = 0,

From 4081669a74afb03173d24222197027938939f5d3 Mon Sep 17 00:00:00 2001
From: Mikhail Melnik <by.zumzoom@gmail.com>
Date: Wed, 20 Nov 2024 16:41:57 +0400
Subject: [PATCH 09/17] fix

---
 test/FeeTaker.js           |  8 +++-----
 test/helpers/orderUtils.js | 15 +++++++--------
 2 files changed, 10 insertions(+), 13 deletions(-)

diff --git a/test/FeeTaker.js b/test/FeeTaker.js
index e96186f7..3c6f32b7 100644
--- a/test/FeeTaker.js
+++ b/test/FeeTaker.js
@@ -6,7 +6,7 @@ const { deploySwapTokens } = require('./helpers/fixtures');
 const { buildOrder, buildTakerTraits, signOrder, buildMakerTraits, buildFeeTakerExtensions } = require('./helpers/orderUtils');
 const { ether } = require('./helpers/utils');
 
-describe.only('FeeTaker', function () {
+describe('FeeTaker', function () {
     let addr, addr1, addr2, addr3;
     before(async function () {
         [addr, addr1, addr2, addr3] = await ethers.getSigners();
@@ -109,7 +109,7 @@ describe.only('FeeTaker', function () {
         const integratorFee = BigInt(1e4);
         const resolverFee = BigInt(1e3);
         const feeRecipient = addr2.address;
-        const whitelist = '0x' + addr.address.slice(-20).repeat(10);
+        const whitelist = '0x0a' + addr.address.slice(-20).repeat(10);
 
         const order = buildOrder(
             {
@@ -125,7 +125,6 @@ describe.only('FeeTaker', function () {
                 feeRecipient,
                 integratorFee,
                 resolverFee,
-                whitelistLength: 10,
                 whitelist,
             }),
         );
@@ -151,7 +150,7 @@ describe.only('FeeTaker', function () {
         const integratorFee = BigInt(1e4);
         const resolverFee = BigInt(1e3);
         const feeRecipient = addr2.address;
-        const whitelist = '0x' + addr2.address.slice(-20).repeat(10);
+        const whitelist = '0x0a' + addr2.address.slice(-20).repeat(10);
 
         const order = buildOrder(
             {
@@ -167,7 +166,6 @@ describe.only('FeeTaker', function () {
                 feeRecipient,
                 integratorFee,
                 resolverFee,
-                whitelistLength: 10,
                 whitelist,
             }),
         );
diff --git a/test/helpers/orderUtils.js b/test/helpers/orderUtils.js
index c29958fb..5b574c5d 100644
--- a/test/helpers/orderUtils.js
+++ b/test/helpers/orderUtils.js
@@ -132,27 +132,26 @@ function buildFeeTakerExtensions ({
     integratorFee = 0,
     resolverFee = 0,
     whitelistDiscount = 50,
-    whitelistLength = 0,
-    whitelist = '0x',
+    whitelist = '0x00',
     whitelistPostInteraction = whitelist,
 }) {
     return {
         makingAmountData: ethers.solidityPacked(
-            ['address', 'bytes', 'uint16', 'uint16', 'uint8', 'uint8', 'bytes'],
-            [feeTaker, getterExtraPrefix, integratorFee, resolverFee, whitelistDiscount, whitelistLength, whitelist],
+            ['address', 'bytes', 'uint16', 'uint16', 'uint8', 'bytes'],
+            [feeTaker, getterExtraPrefix, integratorFee, resolverFee, whitelistDiscount, whitelist],
         ),
         takingAmountData: ethers.solidityPacked(
-            ['address', 'bytes', 'uint16', 'uint16', 'uint8', 'uint8', 'bytes'],
-            [feeTaker, getterExtraPrefix, integratorFee, resolverFee, whitelistDiscount, whitelistLength, whitelist],
+            ['address', 'bytes', 'uint16', 'uint16', 'uint8', 'bytes'],
+            [feeTaker, getterExtraPrefix, integratorFee, resolverFee, whitelistDiscount, whitelist],
         ),
         postInteraction: ethers.solidityPacked(
             ['address', 'bytes1', 'address'].concat(
                 makerReceiver ? ['address'] : [],
-                ['uint16', 'uint16', 'uint8', 'uint8', 'bytes'],
+                ['uint16', 'uint16', 'uint8', 'bytes'],
             ),
             [feeTaker, makerReceiver ? '0x01' : '0x00', feeRecipient].concat(
                 makerReceiver ? [makerReceiver] : [],
-                [integratorFee, resolverFee, whitelistDiscount, whitelistLength, whitelistPostInteraction],
+                [integratorFee, resolverFee, whitelistDiscount, whitelistPostInteraction],
             ),
         ),
     };

From 11448df06adefc0e81e217c3c5b8cd830b4e90c1 Mon Sep 17 00:00:00 2001
From: Mikhail Melnik <by.zumzoom@gmail.com>
Date: Wed, 20 Nov 2024 16:54:24 +0400
Subject: [PATCH 10/17] allow bypassing FeeTaker

---
 contracts/extensions/FeeTaker.sol | 27 ++++++++++++++++++---------
 test/FeeTaker.js                  | 14 +++-----------
 2 files changed, 21 insertions(+), 20 deletions(-)

diff --git a/contracts/extensions/FeeTaker.sol b/contracts/extensions/FeeTaker.sol
index 18445a13..5d372d44 100644
--- a/contracts/extensions/FeeTaker.sol
+++ b/contracts/extensions/FeeTaker.sol
@@ -38,6 +38,11 @@ contract FeeTaker is IPostInteraction, AmountGetterWithFee, Ownable {
      */
     error EthTransferFailed();
 
+    /**
+     * @dev Fee taker is set to be receiver but no fees were set.
+     */
+    error InconsistentFee();
+
     address private immutable _LIMIT_ORDER_PROTOCOL;
     address private immutable _WETH;
     /// @notice Contract address whose tokens allow filling limit orders with a fee for resolvers that are outside the whitelist
@@ -128,16 +133,20 @@ contract FeeTaker is IPostInteraction, AmountGetterWithFee, Ownable {
             // fee is calculated as a sum of separate fees to limit rounding errors
             uint256 fee = Math.mulDiv(takingAmount, integratorFee, denominator) + Math.mulDiv(takingAmount, resolverFee, denominator);
 
-            if (order.takerAsset.get() == address(_WETH) && order.makerTraits.unwrapWeth()) {
-                if (fee > 0) {
-                    _sendEth(feeRecipient, fee);
-                }
-                _sendEth(receiver, takingAmount - fee);
-            } else {
-                if (fee > 0) {
-                    IERC20(order.takerAsset.get()).safeTransfer(feeRecipient, fee);
+            if (order.receiver.get() == address(this)) {
+                if (fee == 0) revert InconsistentFee();
+
+                if (order.takerAsset.get() == address(_WETH) && order.makerTraits.unwrapWeth()) {
+                    if (fee > 0) {
+                        _sendEth(feeRecipient, fee);
+                    }
+                    _sendEth(receiver, takingAmount - fee);
+                } else {
+                    if (fee > 0) {
+                        IERC20(order.takerAsset.get()).safeTransfer(feeRecipient, fee);
+                    }
+                    IERC20(order.takerAsset.get()).safeTransfer(receiver, takingAmount - fee);
                 }
-                IERC20(order.takerAsset.get()).safeTransfer(receiver, takingAmount - fee);
             }
 
             if (tail.length >= 20) {
diff --git a/test/FeeTaker.js b/test/FeeTaker.js
index 3c6f32b7..c9d31cab 100644
--- a/test/FeeTaker.js
+++ b/test/FeeTaker.js
@@ -45,16 +45,12 @@ describe('FeeTaker', function () {
         const order = buildOrder(
             {
                 maker: addr1.address,
-                receiver: await feeTaker.getAddress(),
                 makerAsset: await dai.getAddress(),
                 takerAsset: await weth.getAddress(),
                 makingAmount,
                 takingAmount,
             },
-            buildFeeTakerExtensions({
-                feeTaker: await feeTaker.getAddress(),
-                feeRecipient,
-            }),
+            buildFeeTakerExtensions({ feeTaker: await feeTaker.getAddress() }),
         );
 
         const { r, yParityAndS: vs } = ethers.Signature.from(await signOrder(order, chainId, await swap.getAddress(), addr1));
@@ -78,17 +74,13 @@ describe('FeeTaker', function () {
         const order = buildOrder(
             {
                 maker: addr1.address,
-                receiver: await feeTaker.getAddress(),
+                receiver: makerReceiver,
                 makerAsset: await dai.getAddress(),
                 takerAsset: await weth.getAddress(),
                 makingAmount,
                 takingAmount,
             },
-            buildFeeTakerExtensions({
-                feeTaker: await feeTaker.getAddress(),
-                feeRecipient,
-                makerReceiver,
-            }),
+            buildFeeTakerExtensions({ feeTaker: await feeTaker.getAddress() }),
         );
 
         const { r, yParityAndS: vs } = ethers.Signature.from(await signOrder(order, chainId, await swap.getAddress(), addr1));

From 248d9d27593668c45a2159f3189fdd2cda7dba0a Mon Sep 17 00:00:00 2001
From: Mikhail Melnik <by.zumzoom@gmail.com>
Date: Wed, 20 Nov 2024 16:56:17 +0400
Subject: [PATCH 11/17] allow custom extra data

---
 test/helpers/orderUtils.js | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/test/helpers/orderUtils.js b/test/helpers/orderUtils.js
index 5b574c5d..74ab54c3 100644
--- a/test/helpers/orderUtils.js
+++ b/test/helpers/orderUtils.js
@@ -134,24 +134,27 @@ function buildFeeTakerExtensions ({
     whitelistDiscount = 50,
     whitelist = '0x00',
     whitelistPostInteraction = whitelist,
+    customMakingGetter = '0x',
+    customTakingGetter = '0x',
+    customPostInteraction = '0x',
 }) {
     return {
         makingAmountData: ethers.solidityPacked(
-            ['address', 'bytes', 'uint16', 'uint16', 'uint8', 'bytes'],
-            [feeTaker, getterExtraPrefix, integratorFee, resolverFee, whitelistDiscount, whitelist],
+            ['address', 'bytes', 'uint16', 'uint16', 'uint8', 'bytes', 'bytes'],
+            [feeTaker, getterExtraPrefix, integratorFee, resolverFee, whitelistDiscount, whitelist, customMakingGetter],
         ),
         takingAmountData: ethers.solidityPacked(
-            ['address', 'bytes', 'uint16', 'uint16', 'uint8', 'bytes'],
-            [feeTaker, getterExtraPrefix, integratorFee, resolverFee, whitelistDiscount, whitelist],
+            ['address', 'bytes', 'uint16', 'uint16', 'uint8', 'bytes', 'bytes'],
+            [feeTaker, getterExtraPrefix, integratorFee, resolverFee, whitelistDiscount, whitelist, customTakingGetter],
         ),
         postInteraction: ethers.solidityPacked(
             ['address', 'bytes1', 'address'].concat(
                 makerReceiver ? ['address'] : [],
-                ['uint16', 'uint16', 'uint8', 'bytes'],
+                ['uint16', 'uint16', 'uint8', 'bytes', 'bytes'],
             ),
             [feeTaker, makerReceiver ? '0x01' : '0x00', feeRecipient].concat(
                 makerReceiver ? [makerReceiver] : [],
-                [integratorFee, resolverFee, whitelistDiscount, whitelistPostInteraction],
+                [integratorFee, resolverFee, whitelistDiscount, whitelistPostInteraction, customPostInteraction],
             ),
         ),
     };

From d6b40b6e8fe579805eb70d925fb1044474eddcdd Mon Sep 17 00:00:00 2001
From: Mikhail Melnik <by.zumzoom@gmail.com>
Date: Wed, 20 Nov 2024 17:59:10 +0400
Subject: [PATCH 12/17] fix

---
 contracts/extensions/FeeTaker.sol | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/contracts/extensions/FeeTaker.sol b/contracts/extensions/FeeTaker.sol
index 5d372d44..a601b137 100644
--- a/contracts/extensions/FeeTaker.sol
+++ b/contracts/extensions/FeeTaker.sol
@@ -134,7 +134,7 @@ contract FeeTaker is IPostInteraction, AmountGetterWithFee, Ownable {
             uint256 fee = Math.mulDiv(takingAmount, integratorFee, denominator) + Math.mulDiv(takingAmount, resolverFee, denominator);
 
             if (order.receiver.get() == address(this)) {
-                if (fee == 0) revert InconsistentFee();
+                if (integratorFee + resolverFee == 0) revert InconsistentFee();
 
                 if (order.takerAsset.get() == address(_WETH) && order.makerTraits.unwrapWeth()) {
                     if (fee > 0) {

From a27230667f09252a8e37c6c0b4f479919e26e607 Mon Sep 17 00:00:00 2001
From: Mikhail Melnik <by.zumzoom@gmail.com>
Date: Thu, 21 Nov 2024 00:09:57 +0400
Subject: [PATCH 13/17] fix

---
 contracts/extensions/FeeTaker.sol | 2 --
 1 file changed, 2 deletions(-)

diff --git a/contracts/extensions/FeeTaker.sol b/contracts/extensions/FeeTaker.sol
index a601b137..dcc097c7 100644
--- a/contracts/extensions/FeeTaker.sol
+++ b/contracts/extensions/FeeTaker.sol
@@ -134,8 +134,6 @@ contract FeeTaker is IPostInteraction, AmountGetterWithFee, Ownable {
             uint256 fee = Math.mulDiv(takingAmount, integratorFee, denominator) + Math.mulDiv(takingAmount, resolverFee, denominator);
 
             if (order.receiver.get() == address(this)) {
-                if (integratorFee + resolverFee == 0) revert InconsistentFee();
-
                 if (order.takerAsset.get() == address(_WETH) && order.makerTraits.unwrapWeth()) {
                     if (fee > 0) {
                         _sendEth(feeRecipient, fee);

From a38b830b93ee8164ac99c55ad916474b0857495f Mon Sep 17 00:00:00 2001
From: Mikhail Melnik <by.zumzoom@gmail.com>
Date: Thu, 21 Nov 2024 00:22:45 +0400
Subject: [PATCH 14/17] cleanup

---
 contracts/extensions/FeeTaker.sol | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/contracts/extensions/FeeTaker.sol b/contracts/extensions/FeeTaker.sol
index dcc097c7..02eeeb9a 100644
--- a/contracts/extensions/FeeTaker.sol
+++ b/contracts/extensions/FeeTaker.sol
@@ -38,11 +38,6 @@ contract FeeTaker is IPostInteraction, AmountGetterWithFee, Ownable {
      */
     error EthTransferFailed();
 
-    /**
-     * @dev Fee taker is set to be receiver but no fees were set.
-     */
-    error InconsistentFee();
-
     address private immutable _LIMIT_ORDER_PROTOCOL;
     address private immutable _WETH;
     /// @notice Contract address whose tokens allow filling limit orders with a fee for resolvers that are outside the whitelist

From 5e7ca6409d9d111ccbc8c1b7e186eb5f99bb9429 Mon Sep 17 00:00:00 2001
From: Mikhail Melnik <by.zumzoom@gmail.com>
Date: Tue, 26 Nov 2024 12:56:17 +0400
Subject: [PATCH 15/17] fix typo

---
 contracts/extensions/AmountGetterWithFee.sol | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/contracts/extensions/AmountGetterWithFee.sol b/contracts/extensions/AmountGetterWithFee.sol
index b8f283e5..9c726ca4 100644
--- a/contracts/extensions/AmountGetterWithFee.sol
+++ b/contracts/extensions/AmountGetterWithFee.sol
@@ -88,7 +88,7 @@ contract AmountGetterWithFee is AmountGetterBase {
      * @param whitelistData Whitelist data is a tightly packed struct of the following format:
      * ```
      * 1 byte - size of the whitelist
-     * (bytes10)[N] whiteliested addresses;
+     * (bytes10)[N] whitelisted addresses;
      * ```
      * Only 10 lowest bytes of the address are used for comparison.
      * @param taker The taker address to check.

From 34234a3a877712842db3ea77a3cb1850bd7a1290 Mon Sep 17 00:00:00 2001
From: Mikhail Melnik <by.zumzoom@gmail.com>
Date: Tue, 26 Nov 2024 13:30:00 +0400
Subject: [PATCH 16/17] revert when fee > 0 but receiver is not FeeTaker

---
 contracts/extensions/FeeTaker.sol | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/contracts/extensions/FeeTaker.sol b/contracts/extensions/FeeTaker.sol
index 02eeeb9a..8d9a71e9 100644
--- a/contracts/extensions/FeeTaker.sol
+++ b/contracts/extensions/FeeTaker.sol
@@ -38,6 +38,11 @@ contract FeeTaker is IPostInteraction, AmountGetterWithFee, Ownable {
      */
     error EthTransferFailed();
 
+    /**
+      * @dev Fees are specified but FeeTaker is not set as a receiver.
+      */
+    error InconsistentFee();
+
     address private immutable _LIMIT_ORDER_PROTOCOL;
     address private immutable _WETH;
     /// @notice Contract address whose tokens allow filling limit orders with a fee for resolvers that are outside the whitelist
@@ -140,6 +145,8 @@ contract FeeTaker is IPostInteraction, AmountGetterWithFee, Ownable {
                     }
                     IERC20(order.takerAsset.get()).safeTransfer(receiver, takingAmount - fee);
                 }
+            } else if (fee > 0) {
+                revert InconsistentFee();
             }
 
             if (tail.length >= 20) {

From 994e529681f487b22ee14d9e52572f9d02ea862a Mon Sep 17 00:00:00 2001
From: Mikhail Melnik <by.zumzoom@gmail.com>
Date: Tue, 10 Dec 2024 14:55:14 +0400
Subject: [PATCH 17/17] add natspec

Co-authored-by: Xenia <94478708+byshape@users.noreply.github.com>
---
 contracts/extensions/FeeTaker.sol | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/contracts/extensions/FeeTaker.sol b/contracts/extensions/FeeTaker.sol
index 8d9a71e9..e808ce06 100644
--- a/contracts/extensions/FeeTaker.sol
+++ b/contracts/extensions/FeeTaker.sol
@@ -72,6 +72,9 @@ contract FeeTaker is IPostInteraction, AmountGetterWithFee, Ownable {
      */
     receive() external payable {}
 
+    /**
+     * @notice See {IPostInteraction-postInteraction}.
+     */
     function postInteraction(
         IOrderMixin.Order calldata order,
         bytes calldata extension,