extends.js

class MainApp extends StatelessWidget {
  final FirebaseUser user;
  final token;

  const MainApp({Key key, this.token, this.user}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    final HttpLink httpLink = HttpLink(
      uri: '<your-graphql-endpoint>',
    );

    final WebSocketLink websocketLink = WebSocketLink(
      url: 'wss://<your-graphql-endpoint>,
      config: SocketClientConfig(
        autoReconnect: true,
        inactivityTimeout: Duration(seconds: 30),
      ),
    );

    final AuthLink authLink = AuthLink(
      getToken: () async => 'Bearer ' + token,
    );

    final Link link = authLink.concat(httpLink as Link).concat(websocketLink);

    ValueNotifier<GraphQLClient> client = ValueNotifier(
      GraphQLClient(
        cache: InMemoryCache(),
        link: link,
      ),
    );

    return GraphQLProvider(
      client: client,
      child: MaterialApp(
        theme: ThemeData(primarySwatch: Colors.red),
        home: Menu(
          user: user,
        ),
      ),
    );
  }
}