First Flight #10: One Shot

Description:

• After a battle is finished, the winner should receive a status update on battlesWon. However, this never happens.

• Impact:

  • The bonus over battles won is not applied. Breaking the functionality.

• Proof of Concept:

  Add the code below to `OneShot.t.sol`

  function testBattleWonNeverUpdated() public mintRapper {

  vm.startPrank(user);

  oneShot.approve(address(rapBattle), 0);

  rapBattle.goOnStageOrBattle(0, 0);

  vm.stopPrank();

  vm.startPrank(challenger);

  oneShot.mintRapper();

  oneShot.approve(address(rapBattle), 1);

  rapBattle.goOnStageOrBattle(1, 0);

  ​

  IOneShot.RapperStats memory statsDefender = oneShot.getRapperStats(0);

  IOneShot.RapperStats memory statsChallenger = oneShot.getRapperStats(1);

  ​

  console.log(statsDefender.battlesWon);

  console.log(statsChallenger.battlesWon);

  }

• Recommendation:

  Update the `OneShot.sol::onlyStreetContract` modifier to accept calls from `RapBattle.sol::_battle` and create the helpe function below

  + modifier onlyStreetContract() {

  + require(msg.sender == address(_streetsContract) || msg.sender == address(s_rap), "Not Allowed");

  + _;

  + }

  ​

  + import {RapBattle} from "./RapBattle.sol";

  ​

  + event OneShot__RapBattleAddressUpdated();

  ​

  + function setRapBattleContract(address _rapBattle) external onlyOwner {

  + s_rap = RapBattle(_rapBattle);

  ​

  + emit OneShot__RapBattleAddressUpdated();

  + }

  ​
  Update the `RapBattle.sol::_battle` as follow

  function _battle(uint256 _tokenId, uint256 _credBet) internal {

  address _defender = defender;

  require(defenderBet == _credBet, "RapBattle: Bet amounts do not match");

  uint256 defenderRapperSkill = getRapperSkill(defenderTokenId);

  uint256 challengerRapperSkill = getRapperSkill(_tokenId);

  uint256 totalBattleSkill = defenderRapperSkill + challengerRapperSkill;

  uint256 totalPrize = defenderBet + _credBet;

  ​

  uint256 random =

  uint256(keccak256(abi.encodePacked(block.timestamp, block.prevrandao, msg.sender))) % totalBattleSkill;

  ​

  // Reset the defender

  defender = address(0);

  ​

  emit Battle(msg.sender, _tokenId, random < defenderRapperSkill ? _defender : msg.sender);

  ​

  // If random <= defenderRapperSkill -> defenderRapperSkill wins, otherwise they lose

  if (random <= defenderRapperSkill) {

  + IOneShot.RapperStats memory stats = oneShotNft.getRapperStats(defenderTokenId);

  + stats.battlesWon++;

  + oneShotNft.updateRapperStats(defenderTokenId, stats.weakKnees, stats.heavyArms, stats.spaghettiSweater, stats.calmAndReady, stats.battlesWon);

  // We give them the money the defender deposited, and the challenger's bet

  credToken.transfer(_defender, defenderBet);

  credToken.transferFrom(msg.sender, _defender, _credBet);

  } else {

  + IOneShot.RapperStats memory stats = oneShotNft.getRapperStats(_tokenId);

  + stats.battlesWon++;

  + oneShotNft.updateRapperStats(_tokenId, stats.weakKnees, stats.heavyArms, stats.spaghettiSweater, stats.calmAndReady, stats.battlesWon);

  // Otherwise, since the challenger never sent us the money, we just give the money in the contract

  credToken.transfer(msg.sender, _credBet);

  }

  ​

  totalPrize = 0;

  // Return the defender's NFT

  oneShotNft.transferFrom(address(this), _defender, defenderTokenId);

  }