windows 10 pro office 2019 pro office 365 pro windows 10 home windows 10 enterprise office 2019 home and business office 2016 pro windows 10 education visio 2019 microsoft project 2019 microsoft project 2016 visio professional 2016 windows server 2012 windows server 2016 windows server 2019 Betriebssysteme office software windows server instagram takipçi instagram beğeni instagram görüntüleme instagram otomatik beğeni facebook beğeni facebook sayfa beğenisi facebook takipçi twitter takipçi twitter beğeni twitter retweet youtube izlenme youtube abone instagram

Type error using useReducer and Context with Typescript

Asked By: Anonymous

I’m trying to include Auth with useReducer and Context in a React app, but i have a type error in

<UserDispatchContext.Provider value={dispatch}>

The error is:

Type 'Dispatch<Action>' is not assignable to type '(state: User, action: Action) =>
{ id: number | null; username: string | null; email: string | null; role: 'user' | 'admin'; }'.
  Types of parameters 'value' and 'state' are incompatible.
    Property 'type' is missing in type 'User' but required in type 'Action'.

Those are my types

export interface Action { type: 'login' | 'logout' }

export interface User {
    id: number | null
    username: string | null
    email: string | null
    role: 'user' | 'admin'

this is Auth.tsx

import React, { useReducer, useContext } from 'react'
import { NextPage } from 'next'
import { User, Action } from '../@types/auth'

const user: User = {
    id: null,
    username: null,
    email: null,
    role: null

const reducer = (state: User, action: Action) => {
    switch (action.type) {
        case 'login':
            return {...state}
          return {...state, ...user}

const UserStateContext = React.createContext<User>(user)
const UserDispatchContext = React.createContext<typeof reducer>(reducer)

export const AuthProvider: NextPage = ({ children }) => {

    const [ state, dispatch ] = useReducer(reducer, user)

    return (
        <UserStateContext.Provider value={state}>
            <UserDispatchContext.Provider value={dispatch}>

export const useAuth = () => useContext(UserStateContext)
export const useDispatchAuth = () => useContext(UserDispatchContext)

I have tried something but I can’t figured out.
Maybe I have not understood well how useReducer works.

Thanks in advance


Answered By: Anonymous

It is hard for me to debug this code just by looking at it but I am going to show you very similar code that I have in hopes that you can get something out of it. Main thing is I used typesafe-actions:


import React, { createContext, useContext, useEffect, useReducer } from 'react';
import { ActionType } from 'typesafe-actions';

import * as actions from './app.actions';
import * as userActions from './user/actions';

import * as fromUser from './user/reducer';

interface State {
  user: fromUser.State,

const appReducer = (state: State, action: ActionType<typeof actions>) => ({
  user: fromUser.reducer(state.user, action as ActionType<typeof userActions>),

const initialState: State = {
  user: fromUser.initialState,

const StateContext = createContext(initialState);
const DispatchContext = createContext((_: ActionType<typeof actions>) => { });

interface ProviderProps { children: React.ReactNode }

export const StoreProvider: React.FC<ProviderProps> = ({ children }) => {
  const [state, dispatch] = useReducer(appReducer, initialState);

  useEffect(() => {
    return () => dispatch(actions.appEnd());
  }, []);

  return (
    <StateContext.Provider value={state}>
      <DispatchContext.Provider value={dispatch}>

export function useStore() {
  return useContext(StateContext);

export function useDispatch() {
  return useContext(DispatchContext);


export const ADD_USER = 'user/ADD_USER';
export const addUser = (user: string) => ({
  type: ADD_USER,
} as const);

export const REMOVE_USER = 'user/REMOVE_USER';
export const removeUser = () => ({
  type: REMOVE_USER,
} as const);


import { ActionType } from 'typesafe-actions';

import * as actions from './actions';

export interface State {
  userName: string | null,

export const initialState: State = {
  userName: null,

export const reducer = (state = initialState, action: ActionType<typeof actions>): State => {
  switch (action.type) {
    case actions.ADD_USER: {
      return {
        userName: action.user,
    case actions.REMOVE_USER: {
      return {
        userName: null,
    default: return state;

techinplanet staff

instagram volgers kopen volgers kopen buy windows 10 pro buy windows 11 pro

Windows 10 Kaufen Windows 10 Pro Office 2019 Kaufen Office 365 Lizenz Windows 10 Home Lizenz Office 2019 Home Business Kaufen windows office 365 satın al follower kaufen instagram follower kaufen porno
Alanya escort Manavgat escort Fethiye escort Kemer escort Didim escort Çanakkale escort Aydın escort Muğla escort Tekirdağ escort Manisa escort Balıkesir escort Trabzon escort Elazığ escort Ordu escort Kütahya escort Isparta escort Rize escort Kahramanmaraş escort Yalova escort Giresun escort Yozgat escort Tokat escort Şanlıurfa escort Sivas escort Batman escort Erzurum escort Sinop escort Kırşehir escort Karaman escort Kırıkkale escort Bolu escort Amasya escort Niğde escort Uşak escort Edirne escort Çorum escort Osmaniye escort Zonguldak escort Van escort Erzincan escort Söke escort Bodrum escort Çerkezköy escort Akhisar escort Bandırma escort Ayvacık escort Akçaabat escort Karakoçan escort Altınordu escort Tavşanlı escort Eğirdir escort Ardeşen escort Afşin escort Altınova escort Bulancak escort Sorgun escort Erbaa escort Viranşehir escort Zara escort Kozluk escort Aziziye escort Ayancık escort Kaman escort Ermenek escort Keskin escort Gerede escort Göynücek escort Bor escort Banaz escort Havsa escort Osmancık escort Bahçe escort Alaplı escort Başkale escort Kemah escort Nazilli escort Fethiye escort Çorlu escort Alaşehir escort Altıeylül escort Biga escort Araklı escort Kovancılar escort Fatsa escort Simav escort Yalvaç escort Çayeli escort Dulkadiroğlu escort Çiftlikköy escort Espiye escort Sarıkaya escort Niksar escort Suruç escort Yıldızeli escort Sason escort Horasan escort Boyabat escort Mucur escort Sarıveliler escort Yahşihan escort Göynük escort Gümüşhacıköy escort Çamardı escort Eşme escort İpsala escort Sungurlu escort Hasanbeyli escort Çaycuma escort İpekyolu escort Refahiye escort Kuşadası escort Marmaris escort Süleymanpaşa escort Turgutlu escort Susurluk escort Gelibolu escort Of escort Ünye escort Domaniç escort Fındıklı escort Elbistan escort Çınarcık escort Tirebolu escort Akdağmadeni escort Turhal escort Eyyübiye escort Suşehri escort Yakutiye escort Gerze escort Mengen escort Merzifon escort Ulukışla escort Sivaslı escort Keşan escort Kadirli escort Ereğli escort Özalp escort Tercan escort Efeler escort Didim escort Çine escort Dalaman escort Menteşe escort Milas escort Ortaca escort Seydikemer escort Ergene escort Kapaklı escort Malkara escort Salihli escort Şehzadeler escort Soma escort Yunusemre escort Ayvalık escort Bigadiç escort Burhaniye escort Gönen escort Karesi escort Çan escort Yenice escort Ortahisar escort Yomra escort Perşembe escort Pazar escort Onikişubat escort Pazarcık escort Türkoğlu escort Eynesil escort Görele escort Piraziz escort Yağlıdere escort Çayıralan escort Boğazlıyan escort Zile escort Siverek escort Karaköprü escort Haliliye escort Akçakale escort Şarkışla escort Gemerek escort Oltu escort Palandöken escort Mudurnu escort Suluova escort Taşova escort Toprakkale escort Kilimli escort Tuşba escort Üzümlü escort