Nextjs urql subscription exchange import problem - reactjs

Question

i can't get urql subscriptions to work with NextJS because of imports problem.
Basically i'm using this graphql-ws lib that is recommended in urql docs, that needs ws implementation library (eg: 'ws'). And when i import WebSocket from 'ws' i get this error: Module not found: Can't resolve 'net'
import { createClient, defaultExchanges, subscriptionExchange, Client } from 'urql';
import { createClient as createWSClient } from 'graphql-ws';
import WebSocket from 'ws'; // <-- This causes the error
export const createUrqlClient = (): Client => {
const wsClient = createWSClient({
url: 'ws://xxx/graphql',
webSocketImpl: WebSocket,
});
const client = createClient({
url: 'http://xxx/graphql',
exchanges: [
...defaultExchanges,
subscriptionExchange({
forwardSubscription: operation => ({
subscribe: sink => ({
unsubscribe: wsClient.subscribe(operation, sink),
}),
}),
}),
],
});
return client;
};
I tried nextjs dynamic import and both of these didn't work as well:
const WebSocket = dynamic(() => import('ws'), { ssr: false });
const WebSocket = dynamic(() => import('ws').then(module => module.default), { ssr: false });
I also tried to alter webpack config in next.config.js to not bundle these libs at all:
webpack: (config, { isServer }) => {
if (!isServer) {
config.resolve.fallback = {
child_process: false,
process: false,
fs: false,
util: false,
http: false,
https: false,
tls: false,
net: false,
crypto: false,
path: false,
os: false,
stream: false,
zlib: false,
querystring: false,
events: false,
'utf-8-validate': false,
bufferutil: false,
};
}
return config;
},
but then i get these errors:
./node_modules/ws/lib/validation.js
Module not found: Can't resolve 'utf-8-validate' in '/home/danko/app/node_modules/ws/lib'
warn - ./node_modules/ws/lib/buffer-util.js
Module not found: Can't resolve 'bufferutil' in '/home/danko/app/node_modules/ws/lib'
if i add 'utf-8-validate': false and bufferutil: false to the cfg as well i get this err:
TypeError: Class extends value undefined is not a constructor or null
So basically nothing works properly then as you can see...
How hard can this be, i can't be the only person that uses urql subscriptions with nextjs, hope somebody can help me with this. Thanks!

Answer 1

Basically as i thought, impl was not needed because native html5 websocket can be used, problem was trash nextjs with it's server side thing.
I pretty much don't use that exchange when typeof window !== 'undefined'
this is the working code:
import { createClient, dedupExchange, cacheExchange, subscriptionExchange, Client, Exchange } from 'urql';
import { multipartFetchExchange } from '#urql/exchange-multipart-fetch';
import { createClient as createWSClient } from 'graphql-ws';
export const createUrqlClient = (): Client => {
const graphqlEndpoint = process.env!.NEXT_PUBLIC_GRAPHQL_ENDPOINT as string;
const graphqlWebsocketEndpoint = process.env!.NEXT_PUBLIC_GRAPHQL_WS_ENDPOINT as string;
let exchanges: Exchange[] | undefined = [dedupExchange, cacheExchange, multipartFetchExchange];
if (typeof window !== 'undefined') {
const wsClient = createWSClient({
url: graphqlWebsocketEndpoint,
});
const subExchange = subscriptionExchange({
forwardSubscription: operation => ({
subscribe: sink => ({
unsubscribe: wsClient.subscribe(operation, sink),
}),
}),
});
exchanges.push(subExchange);
}
const client = createClient({
url: graphqlEndpoint,
requestPolicy: 'cache-and-network',
exchanges,
fetchOptions: () => ({
credentials: 'include',
}),
});
return client;
};

Answer 2

#dankobgd
I had the same problem and your answer helped me.
I simplified a bit and it's working
export const client = (): Client => {
let exchanges: Exchange[] = [...defaultExchanges]
if (typeof window !== 'undefined') {
const wsClient = createWSClient({
url: wsUrl,
})
const subExchange = subscriptionExchange({
forwardSubscription: (operation) => ({
subscribe: (sink) => ({
unsubscribe: wsClient.subscribe(operation, sink),
}),
}),
})
exchanges.push(subExchange)
}
return createClient({
url,
exchanges,
})
}