Adding types to async func inside createAsyncThunk-CodePudding

I've got an issue by trying to add types for arguments while creating async function in createAsyncThunk:

export const setLangAsync = createAsyncThunk<
  { lang: string },
  { fileName: string },
  { getState: RootState; dispatch: AppDispatch }
>(
  'i18n/setLangAsync',
  async (lang: string, fileName: string, { getState, dispatch }) => {
 ...
}

here is the error:

(parameter) getState: any
Argument of type '(lang: string, fileName: string, { getState, dispatch }: 
{ getState: any; dispatch: any; }) => Promise<unknown>' 
is not assignable to parameter of type 'AsyncThunkPayloadCreator<
{ lang: string; }, { fileName: string; }, { getState: { i18n: I18nInterface; }; 
dispatch: ThunkDispatch<...> & Dispatch<...>; }>'.ts(2345)
Binding element 'getState' implicitly has an 'any' type.ts(7031

I seem to be totally lost here. I hope someone could help me to understand what I'm doing wrong. Thank you in advance!

CodePudding user response：

createAsyncThunk's payload creator function takes two arguments, not three.

As for the generic arguments:

the first is the return type
the second is the argument type
the third are various options

export const setLangAsync = createAsyncThunk<
  WhatEverTheFunctionReturnTypeIs,
  { lang: string, fileName: string },
  { getState: RootState; dispatch: AppDispatch }
>(
  'i18n/setLangAsync',
  async ({ lang, fileName }, { getState, dispatch }) => {
 ...
}