export const CitiesProvider = ({
  children,
}: {
  children: React.ReactNode;
}): JSX.Element => {
  const [citiesState, setCitiesState] = useLocalStorage<CitiesState>(
    'citiesState',
    citiesStateInitValue,
  );
  const addCity = (id: number) => {
    if (citiesState.citiesList.includes(id)) {
      return;
    }
    setCitiesState(
      (state: CitiesState): CitiesState => ({
        ...state,
        citiesList: [...citiesState.citiesList, id],
      }),
    );
  };
// removeCity..,  setCurrentCity..
  return (
    <СitiesContext.Provider
      value={{
        currentCity: citiesState.currentCity,
        cities: citiesState.citiesList,
        addCity,
        removeCity,
        setCurrentCity,
      }}
    >
      {children}
    </СitiesContext.Provider>
  );
};

import { QueryClient, QueryClientProvider } from 'react-query';
import { ReactQueryDevtools } from 'react-query/devtools';
 
import { CitiesProvider } from './store/cities/cities-provider';
 
const queryClient = new QueryClient();
 
ReactDOM.render(
  <React.StrictMode>
    <QueryClientProvider client={queryClient}>
      <CitiesProvider>
        <App />

const queryCities = useQuery('cities', fetchCitiesFunc);
const cities = queryCities.data || [];

const { isLoading, isIdle, isError, data, error } = useQuery(..

export function useCurrentWeather(): WeatherCache {
  const { currentCity } = useContext(СitiesContext);
 
// запрашиваем список городов
  const queryCities = useQuery('cities', fetchCitiesFunc, {
     refetchOnWindowFocus: false,
    staleTime: 1000 * 60 * 1000,
  });
  const citiesRu = queryCities.data || [];
 
// ищем идентификатор текущего города.. 
 const city = citiesRu.find((city) => {
    if (city === undefined) return false;
    const { id: elId } = city;
    if (currentCity === elId) return true;
    return false;
  });
 
  const { id: weatherId } = city ?? {};
 
// запрашиваем текущую погоду
  const queryWeatherCity = useQuery(
    ['weatherCity', weatherId],
    () => fetchWeatherCityApi(weatherId as number),
    {
      enabled: !!weatherId,
      staleTime: 5 * 60 * 1000,
    },
  );
 
  const { coord } = queryWeatherCity.data ?? {};
 
// запрашиваем прогноз по координатам из предыд. запроса
  const queryForecastCity = useQuery(
    ['forecastCity', coord],
    () => fetchForecastCityApi(coord as Coord),
    {
      enabled: !!coord,
      staleTime: 5 * 60 * 1000,
    },
  );
 
  return {
    city,
    queryWeatherCity,
    queryForecastCity,
  };
}

const queryWeatherCity = useQuery(['weatherCity', weatherId],..

export function Forecast(): React.ReactElement {
  const {
    queryForecastCity: { isFetching, isLoading, isIdle, data: forecast },
  } = useCurrentWeather();
 
  if (isIdle) return <LoadingInfo text="Ожидание загрузки дневного прогноза" />;
  if (isLoading) return <LoadingInfo text="Загружается дневной прогноз" />;
 
  const { daily = [], alerts = [], hourly = [] } = forecast ?? {};
  const dailyForecastNext = daily.slice(1) || [];
 
  return (
    <>
      <Alerts alerts={alerts} />
      <HourlyForecast hourlyForecast={hourly} />
      <DailyForecast dailyForecast={dailyForecastNext} />
      {isFetching && <LoadingInfo text="Обновляется дневной прогноз" />}
    </>
  );
}

import { ReactQueryDevtools } from 'react-query/devtools';

const userQueries = useQueries(
  users.map(user => {
    return {
      queryKey: ['user', user.id],
      queryFn: () => fetchUserById(user.id),
    }
  })

const mutation = useMutation(newTodo => axios.post('/todos', newTodo))