action-with-reset.tsx

interface State {
  // whatever state you want here
}

type Action = { type: "CHANGE" } | { type: "RESET" };

function reducer(state: State, action: Action) {
  const initialState = { ...state };
  switch (action.type) {
    case "CHANGE":
      // do whatever you want to do on change
    case "RESET":
      return { ...initialState };
    default:
      return state;
  }
}