store voters by tokenId (#49)

src/ERC721Flow.sol

@@ -58,7 +58,7 @@ contract ERC721Flow is IERC721Flow, Flow {
         fs.validateVotes(recipientIds, percentAllocations);
         for (uint256 i = 0; i < tokenIds.length; i++) {
             if (!canVoteWithToken(tokenIds[i], msg.sender)) revert NOT_ABLE_TO_VOTE_WITH_TOKEN();
-            _setVotesAllocationForTokenId(tokenIds[i], recipientIds, percentAllocations);
+            _setVotesAllocationForTokenId(tokenIds[i], recipientIds, percentAllocations, msg.sender);
         }
     }
 

src/Flow.sol

@@ -96,17 +96,19 @@ abstract contract Flow is IFlow, UUPSUpgradeable, Ownable2StepUpgradeable, Reent
      * @param bps The basis points of the vote to be split with the recipient.
      * @param tokenId The tokenId owned by the voter.
      * @param totalWeight The voting power of the voter.
+     * @param voter The address of the voter.
      * @dev Requires that the recipient is valid, and the weight is greater than the minimum vote weight.
      * Emits a VoteCast event upon successful execution.
      */
-    function _vote(bytes32 recipientId, uint32 bps, uint256 tokenId, uint256 totalWeight) internal {
+    function _vote(bytes32 recipientId, uint32 bps, uint256 tokenId, uint256 totalWeight, address voter) internal {
         // calculate new member units for recipient and create vote
         (uint128 memberUnits, address recipientAddress, RecipientType recipientType) = fs.createVote(
             recipientId,
             bps,
             tokenId,
             totalWeight,
-            PERCENTAGE_SCALE
+            PERCENTAGE_SCALE,
+            voter
         );
 
         // update member units
@@ -167,21 +169,23 @@ abstract contract Flow is IFlow, UUPSUpgradeable, Ownable2StepUpgradeable, Reent
     function _setVotesAllocationForTokenId(
         uint256 tokenId,
         bytes32[] memory recipientIds,
-        uint32[] memory percentAllocations
+        uint32[] memory percentAllocations,
+        address voter
     ) internal {
         uint256 sum = 0;
         // overflow should be impossible in for-loop index
         for (uint256 i = 0; i < percentAllocations.length; i++) {
             sum += percentAllocations[i];
         }
         if (sum != PERCENTAGE_SCALE) revert INVALID_BPS_SUM();
+        if (voter == address(0)) revert ADDRESS_ZERO();
 
         // update member units for previous votes
         _clearPreviousVotes(tokenId);
 
         // set new votes
         for (uint256 i = 0; i < recipientIds.length; i++) {
-            _vote(recipientIds[i], percentAllocations[i], tokenId, fs.tokenVoteWeight);
+            _vote(recipientIds[i], percentAllocations[i], tokenId, fs.tokenVoteWeight, voter);
         }
     }
 

src/NounsFlow.sol

@@ -142,7 +142,7 @@ contract NounsFlow is INounsFlow, Flow {
         for (uint256 i = 0; i < tokenIds.length; i++) {
             if (!verifier.canVoteWithToken(tokenIds[i], owner, msg.sender, ownershipProofs[i], delegateProof))
                 revert NOT_ABLE_TO_VOTE_WITH_TOKEN();
-            _setVotesAllocationForTokenId(tokenIds[i], recipientIds, percentAllocations);
+            _setVotesAllocationForTokenId(tokenIds[i], recipientIds, percentAllocations, msg.sender);
         }
     }
 

src/library/FlowVotes.sol

@@ -11,7 +11,8 @@ library FlowVotes {
         uint32 bps,
         uint256 tokenId,
         uint256 totalWeight,
-        uint256 percentageScale
+        uint256 percentageScale,
+        address voter
     ) public returns (uint128 memberUnits, address recipientAddress, FlowTypes.RecipientType recipientType) {
         recipientAddress = fs.recipients[recipientId].recipient;
         recipientType = fs.recipients[recipientId].recipientType;
@@ -29,6 +30,7 @@ library FlowVotes {
 
         // update votes, track recipient, bps, and total member units assigned
         fs.votes[tokenId].push(FlowTypes.VoteAllocation({ recipientId: recipientId, bps: bps, memberUnits: newUnits }));
+        fs.voters[tokenId] = voter;
     }
 
     /**

src/storage/FlowStorageV1.sol

@@ -78,6 +78,8 @@ interface FlowTypes {
         uint256 tokenVoteWeight;
         // The mapping of a token to a list of votes allocations (recipient, BPS)
         mapping(uint256 => VoteAllocation[]) votes;
+        // The mapping of a token to the address that voted with it
+        mapping(uint256 => address) voters;
     }
 }