subscribe is not a function

[apollographql]

subscribe is not a function

[anuj-kosambi]

Hi @lifeiscontent
I was facing similar error, as far as i know It is occurred due to new ApolloLink(async (operation, forward) => {,
after removing async it works fine for me.
To implement async functions, here is my attempt

const authMiddleware = new ApolloLink(
  (operation, forward) =>
    new Observable(observer => {
      AsyncStorage.getItem('token')
        .then(token => {
           operation.setContext({
            headers,
          });
        })
        .then(() => {
          const subscriber = {
            next: observer.next.bind(observer),
            error: observer.error.bind(observer),
            complete: observer.complete.bind(observer),
          };
          forward(operation).subscribe(subscriber);
        })
        .catch(err => {
          observer.error(err);
        });
    })
);

[lifeiscontent]

@AnujKosambi I actually got it to work. You can see my example here:

import { AsyncStorage } from 'react-native';
import {
  InMemoryCache,
  IntrospectionFragmentMatcher
} from 'apollo-cache-inmemory';
import { ApolloClient } from 'apollo-client';
import { HttpLink } from 'apollo-link-http';
import { onError } from 'apollo-link-error';
import { setContext } from 'apollo-link-context';
import fragmentTypes from './data/fragmentTypes';

const httpLink = new HttpLink({ uri: '/graphql' });

let token;

const withToken = setContext(async request => {
  if (!token) {
    token = await AsyncStorage.getItem('token');
  }
  return {
    headers: {
      authorization: token
    }
  };
});

const resetToken = onError(({ networkError }) => {
  if (networkError && networkError.statusCode === 401) {
    // remove cached token on 401 from the server
    token = undefined;
  }
});

const authFlowLink = withToken.concat(resetToken);

const link = authFlowLink.concat(httpLink);

const cache = new InMemoryCache({
  fragmentMatcher: new IntrospectionFragmentMatcher({
    introspectionQueryResultData: fragmentTypes
  })
});

export default new ApolloClient({
  link,
  cache
});