graphql: fix nonce for pending accounts (#24443)

graphql/graphql.go

@@ -100,6 +100,14 @@ func (a *Account) Balance(ctx context.Context) (hexutil.Big, error) {
 }
 
 func (a *Account) TransactionCount(ctx context.Context) (hexutil.Uint64, error) {
+	// Ask transaction pool for the nonce which includes pending transactions
+	if blockNr, ok := a.blockNrOrHash.Number(); ok && blockNr == rpc.PendingBlockNumber {
+		nonce, err := a.backend.GetPoolNonce(ctx, a.address)
+		if err != nil {
+			return 0, err
+		}
+		return hexutil.Uint64(nonce), nil
+	}
 	state, err := a.getState(ctx)
 	if err != nil {
 		return 0, err