In all of the big and trusted contracts this rule is maintained (for example look at AAVE codebase).

    OpenLevV1.sol, 125, require(borrow == 0 || deposit.mul(10000).div(tv.borrowValue) > vars.marginLimit, "MAM");
    OpenLevV1Lib.sol, 166, uint hAvg = marketValue >= borrowed ? marketValue.sub(borrowed).mul(ratioVars.multiplier).div(borrowed) : 0;
    OpenLevV1.sol, 219, require(repayed >= closeTradeVars.borrowed.mul(closeTradeVars.closeRatio).div(1e18), "IRP"); 
    OpenLevV1Lib.sol, 164, uint cAvg = marketValue >= borrowed ? marketValue.sub(borrowed).mul(ratioVars.multiplier).div(borrowed) : 0;
    OpenLevV1Lib.sol, 276, share = totalShare > 0 && reserve > 0 ? totalShare.mul(amount) / reserve : amount;
    OpenLevV1Lib.sol, 162, uint current = marketValue >= borrowed ? marketValue.sub(borrowed).mul(ratioVars.multiplier).div(borrowed) : 0;
    LPool.sol, 892, require(vars.actualRepayAmount.mul(1e18).div(vars.accountBorrows) <= 105e16, 'repay more than 5%');