76:     function _rubicallPayable(
77:         CallParams memory _params
78:     ) internal returns (bytes memory) {
79:         // charge fee from feeParams
80:         uint256 _msgValue = _chargeFeePayable(_params.feeParams);
81: 
82:         (bool _OK, bytes memory _data) = _params.target.call{value: _msgValue}(
83:             bytes.concat(_params.selector, _params.args)
84:         );
85: 
86:         require(_OK, "low-level call to the router failed");
87: 
88:         return _data;
89:     }
379:     function buyAllAmountWithETH(
380:         ERC20 buy_gem,
381:         uint256 buy_amt,
382:         uint256 max_fill_amount
383:     ) external payable beGoneReentrantScum returns (uint256 fill) {
384:         address _weth = address(wethAddress);
385:         uint256 _before = ERC20(_weth).balanceOf(address(this));
386:         require(
387:             msg.value == max_fill_amount,
388:             "must send as much ETH as max_fill_amount"
389:         );
390:         IWETH(wethAddress).deposit{value: max_fill_amount}(); // Pay with native ETH -> WETH
391: 
392:         if (
393:             IWETH(wethAddress).allowance(address(this), RubiconMarketAddress) <
394:             max_fill_amount
395:         ) {
396:             approveAssetOnMarket(wethAddress);
397:         }
398: 
399:         // An amount in WETH
400:         fill = RubiconMarket(RubiconMarketAddress).buyAllAmount(
401:             buy_gem,
402:             buy_amt,
403:             ERC20(wethAddress),
404:             max_fill_amount
405:         );
406:         IERC20(buy_gem).safeTransfer(msg.sender, fill);
407: 
408:         uint256 _after = ERC20(_weth).balanceOf(address(this));
409:         uint256 delta = _after - _before;
410: 
411:         // Return unspent coins to sender
412:         if (delta > 0) {
413:             IWETH(wethAddress).withdraw(delta);
414:             // msg.sender.transfer(delta);
415:             (bool success, ) = msg.sender.call{value: delta}("");
416:             require(success, "Transfer failed.");
417:         }
418:     }
function test_FeeWrapper_FailsWithETHRefund() public {
    FeeWrapperTarget target = new FeeWrapperTarget(ERC20(address(0)));

    uint256 amount = 1 ether;
    uint256 fee = 0.1 ether;

    vm.deal(alice, amount + fee);

    // Alice will call demoERC20
    vm.startPrank(alice);

    FeeWrapper.CallParams memory callParams;
    callParams.selector = FeeWrapperTarget.demoETH.selector;
    callParams.args = "";
    callParams.target = address(target);
    callParams.feeParams.feeToken = address(0);
    callParams.feeParams.totalAmount = amount + fee;
    callParams.feeParams.feeAmount = fee;
    callParams.feeParams.feeTo = makeAddr("FeeRecipient");

    // The following call will fail, the FeeWrapper contract is not prepared to receive the ETH from the target contract
    vm.expectRevert("low-level call to the router failed");
    feeWrapper.rubicall{value: amount + fee}(callParams);

    vm.stopPrank();
}
