fix: fix vote button being incorrectly disabled (#1122)

This was caused by returning undefined from react query to signal that
the user has no existing vote, but returning undefined is disallowed by
react query.

apps/namadillo/src/App/Governance/ProposalHeader.tsx

@@ -291,7 +291,7 @@ const ProgressBar: React.FC<{
 
 const VoteButton: React.FC<{
   proposal: AtomWithQueryResult<Proposal>;
-  vote: AtomWithQueryResult<VoteType | undefined>;
+  vote: AtomWithQueryResult<VoteType | null>;
   proposalId: bigint;
 }> = ({ proposal, vote, proposalId }) => {
   const navigate = useNavigate();
@@ -317,7 +317,7 @@ const VoteButton: React.FC<{
       const disabled =
         !isExtensionConnected || !canVote.data || status !== "ongoing";
 
-      const voted = typeof vote.data !== "undefined";
+      const voted = vote.data !== null;
       const text = voted ? "Edit Vote" : "Vote";
 
       return {
@@ -344,9 +344,9 @@ const VoteButton: React.FC<{
 };
 
 const VotedLabel: React.FC<{
-  vote: AtomWithQueryResult<VoteType | undefined>;
+  vote: AtomWithQueryResult<VoteType | null>;
 }> = ({ vote }) => {
-  if (vote.isSuccess && typeof vote.data !== "undefined") {
+  if (vote.isSuccess && vote.data !== null) {
     return (
       <VotedLabelComponent vote={vote.data} className="text-xs min-w-22" />
     );

apps/namadillo/src/atoms/proposals/atoms.ts

@@ -38,7 +38,7 @@ export const proposalFamily = atomFamily((id: bigint) =>
 );
 
 export const proposalVoteFamily = atomFamily((id: bigint) =>
-  atomWithQuery<VoteType | undefined>((get) => {
+  atomWithQuery<VoteType | null>((get) => {
     const votedProposals = get(votedProposalsAtom);
     const enablePolling = get(shouldUpdateProposalAtom);
 
@@ -47,7 +47,9 @@ export const proposalVoteFamily = atomFamily((id: bigint) =>
       refetchInterval: enablePolling ? 1000 : false,
       queryKey: ["proposal-vote", id.toString()],
       ...queryDependentFn(async () => {
-        return votedProposals.data!.find((v) => v.proposalId === id)?.vote;
+        return (
+          votedProposals.data!.find((v) => v.proposalId === id)?.vote ?? null
+        );
       }, [votedProposals]),
     };
   })