Pitch: overload vote() in IVotingStrategy to allow for casting a single vote and multiple votes

[0xZakk]

Context

Our current implementation of IVotingStrategy allows someone to cast multiple votes at once by providing an array of encoded votes:

function vote(bytes[] calldata _encodedVotes, address _voterAddress) external virtual payable;

Source

This method is called in the RoundImplementation contract:

  /// @notice Invoked by voter to cast votes
  /// @param encodedVotes encoded vote
  function vote(bytes[] memory encodedVotes) external payable {
    // slither-disable-next-line timestamp
    require(
      roundStartTime <= block.timestamp &&
      block.timestamp <= roundEndTime,
      "Round: Round is not active"
    );

    IVotingStrategy(votingStrategy).vote{value: msg.value}(encodedVotes, msg.sender);
  }

Source

Not every voting strategy is going to want to accept multiple votes. But this method is required by the interface and is the assumed behavior.

Suggested Implementation

We could overload vote() and provide two implementations, one for casting multiple votes and one for casting a single vote:

function vote(bytes calldata _encodedVotes, address _voterAddress) external virtual payable;

function vote(bytes[] calldata _encodedVotes, address _voterAddress) external virtual payable;

We would have to update the RoundImplementation contract and overload the vote() method there too:

/// @notice Invoked by voter to cast votes
/// @param encodedVotes encoded vote
function vote(bytes memory encodedVotes) external payable {
  // slither-disable-next-line timestamp
  require(
    roundStartTime <= block.timestamp &&
    block.timestamp <= roundEndTime,
    "Round: Round is not active"
  );

  IVotingStrategy(votingStrategy).vote{value: msg.value}(encodedVotes, msg.sender);
}

/// @notice Invoked by voter to cast votes
/// @param encodedVotes encoded vote
function vote(bytes[] memory encodedVotes) external payable {
  // slither-disable-next-line timestamp
  require(
    roundStartTime <= block.timestamp &&
    block.timestamp <= roundEndTime,
    "Round: Round is not active"
  );

  IVotingStrategy(votingStrategy).vote{value: msg.value}(encodedVotes, msg.sender);
}

Normally, we would implement an internal _vote() method but I think we should avoid doing that here because we want people to be able to structure their votes however they want and I think we want to avoid looping through the votes array here.

[0xKurt]

Not every voting strategy is going to want to accept multiple votes. But this method is required by the interface and is the assumed behavior.

Do you have a concrete example in mind? I wonder how much of an edge case this is and if passing just an array with one vote wouldn't solve it.