typescriptThunk.ts

import {Action, ActionCreator, Dispatch} from 'redux'
import {ThunkAction} from 'redux-thunk'

const thunk: ActionCreator<ThunkAction<Action, IState, void>> = (
  payload: string
) => {
  return (dispatch: Dispatch<IState>): Action => {
    doSomething(payload)
    return dispatch(someAction())
  }
}