First Flight #2: Puppy Raffle

Summary

THe contract calculates fee and prizePool seperately using their percentages. This causes small loss of wei as the contracts does not support decimals

    uint256 prizePool = (totalAmountCollected * 80) / 100;
    uint256 fee = (totalAmountCollected * 20) / 100;

Vulnerability Details

Smart Contracts does not have decimals. so when getting a percentage of values, there are decimal losses. Calculating the fee as 20% of the totalCollected will cause these lost decimals to be stuck in the contract.

Recommendations

calculate fee as totalAmountCollected - prizePool to keep all the wei