fix(#2920): fix unhandled exception on missing proposal for vote

Author: MSzalowski

CHANGELOG.md

@@ -17,6 +17,7 @@ changes.
 ### Fixed
 
 - Fix calculating votes counting for governance actions
+- Fix crashing backend on unhandled missing proposal from vote [Issue 2920](https://github.com/IntersectMBO/govtool/issues/2920)
 
 ### Changed
 

govtool/backend/src/VVA/API.hs

@@ -278,14 +278,19 @@ getVotes :: App m => HexText -> [GovernanceActionType] -> Maybe GovernanceAction
 getVotes (unHexText -> dRepId) selectedTypes sortMode mSearch = do
   CacheEnv {dRepGetVotesCache} <- asks vvaCache
   (votes, proposals) <- cacheRequest dRepGetVotesCache dRepId $ DRep.getVotes dRepId []
+  
   let voteMap = Map.fromList $ map (\vote@Types.Vote {..} -> (voteProposalId, vote)) votes
+
   processedProposals <- filter (isProposalSearchedFor mSearch) <$> mapSortAndFilterProposals selectedTypes sortMode proposals
+
   return $
     [ VoteResponse
-      { voteResponseVote = voteToResponse (voteMap Map.! read (unpack proposalResponseId))
+      { voteResponseVote = voteToResponse vote
       , voteResponseProposal = proposalResponse
       }
     | proposalResponse@ProposalResponse{proposalResponseId} <- processedProposals
+    , let proposalIdInt = read (unpack proposalResponseId) :: Int
+    , Just vote <- [Map.lookup (toInteger proposalIdInt) voteMap]  -- Ensure we only include proposals with a corresponding vote
     ]
 
 drepInfo :: App m => HexText -> m DRepInfoResponse