React Redux Action Creators with TypeScript - example 1

Store.ts

export const getPeopleActionCreator: ActionCreator<
  ThunkAction<
    Promise<IGotPeopleAction>,  // The type of the last action to be dispatched - will always be promise<T> for async actions
    IPerson[],                  // The type for the data within the last action
    null,                       // The type of the parameter for the nested function 
    IGotPeopleAction            // The type of the last action to be dispatched
  >
> = () => {
  return async (dispatch: Dispatch) => {
    const gettingPeopleAction: IGettingPeopleAction = {
      type: 'GettingPeople',
    };
    dispatch(gettingPeopleAction);
    const people = await getPeopleFromApi();
    const gotPeopleAction: IGotPeopleAction = {
      people,
      type: 'GotPeople',
    };
    return dispatch(gotPeopleAction);
  };
};