Estimate fee

In order to estimate the fee, chains generally expose a simulate functionality which don't actually broadcast the transaction, so shuttle exposes a simulate method.

A very common approach is to have a custom hook that estimates the fee, using the simulate functionality from shuttle.

// useFeeEstimate.ts
import {
  WalletConnection,
  TransactionMsg,
  useShuttle,
} from "@delphi-labs/shuttle";
import { useQuery } from "@tanstack/react-query";
type Props = {
  wallet: WalletConnection;
  messages: TransactionMsg[];
};
export default function useFeeEstimate({ wallet, messages }: Props) {
  const { simulate } = useShuttle();
  return useQuery(
    ["fee-estimate", JSON.stringify(messages), wallet?.id],
    async () => {
      if (!messages || messages.length <= 0 || !wallet) {
        return null;
      }
      const response: SimulateResult = await simulate({
        messages,
        wallet,
      });
      return {
        fee: response.fee?.amount[0],
        gasLimit: response.fee?.gas,
      };
    },
    {
      enabled: !!messages && messages.length > 0 && !!wallet,
    }
  );
}