Can networkerror be catched first

[wukong1995]

when I set http code is 401, and throw new error in server. In chrome network, I get http code is 401 and response data is:

{
  data: {operationName: null},
  errors: [{xxxerror}]
}

see,https://github.com/apollographql/apollo-client/blob/master/src/link/http/createHttpLink.ts#L142-L170, I get graphqlError not networkError, I can't get 401.

[maapteh]

You can catch a 401 also on the client part itself. In link field you can use OnError

import { onError } from '@apollo/client/link/error';

return new ApolloClient({
        ...SNIP...
        link: ApolloLink.from([
            onError(({ graphQLErrors, networkError }) => {
                if (graphQLErrors)
                    graphQLErrors.map(({ message, locations, path }) =>
                        console.log(
                            `[GraphQL error]: Message: ${message}, Location: ${locations}, Path: ${path}`,
                        ),
                    );
                if (networkError)
                    console.log(`[Network error]: ${networkError}`);
            }),
            split(
                (operation: any) => operation.getContext().important === true,
                httpLink as any, // if the test is true -- debatch
                batchHttpLink as any, // otherwise, batching is fine
            ),
        ]),
        ...SNIP...
    });

[wukong1995]

@maapteh my code has it. But, in createHttpLink.ts, it call observer.next(err.result);, not observer.error(err). because data isn't null. when it call next, status code will be lost.

[maapteh]

I think its related to #6612 because the error is lost in SSR calls.

For client side calls i indeed not get the error (in link), but i do get it on component .
For server-side calls i do get the error (in link), but i dont get it on component.

{"graphQLErrors":[{"message":"must authenticate","locations":[{"line":2,"column":3}],"path":["authenticationError"],"extensions":{"code":"UNAUTHENTICATED"}}],"networkError":null,"message":"must authenticate"}

i added a page to my sandbox repo to show your scenario on it as well

[wukong1995]

@maapteh my scenario is in client side. In my application, server is nodejs.

// server
ctx.status = 403
throw new Error('no authenticate')

then, i will get graphQLErrors in onError.

In my app, it has 401, 403, 405 and has same error message. so i can't distinguish errors based on error message.

[maapteh]

instead of AuthenticationError, did you play with ApolloError? ApolloError accepts errorCode (string).

        bad: () => {
            console.log('[server] GraphQL server query: bad');
            throw new ApolloError('oeps', '401');
        },
        authenticationError: () => {
            throw new AuthenticationError('must authenticate');
        },

[wukong1995]

@maapteh got it. I will try. thanks.

[wukong1995]

it can solve my problem. i will close issue.