How to prevent error propagation in Apollo Client useQuery in react? - error-handling

Question

I'd like to catch the error in component level and prevent propagation while using the useQuery in #apollo/react-hook.
Here is my example code
const invitationDocument = gql`
query DecodeInvitation($token: String!) {
DecodeInvitation(token: $token) {
name
email
}
}
`
const InvitationPage = (props) => {
const { data, error, loading } = useQuery(invitationDocument, {variables: { token: "XXXX" }});
if(error)
{
return <InvitationErrorPage error={error.message}/>
}
return loading? <LoadingPage> : <InvitationAcceptPage />
}
It works fine but at the same time, the error is being propagated to its parents level so I get another error notification message which comes from the error handler at the global level.
At the application level, I use the apollo-link-error to manage the Graphql errors.
import { onError } from 'apollo-link-error';
const errorLink = onError (({ graphqlErrors, networkError }) => {
if(graphqlErrors)
notification.error(graphqlErrors[0].message);
});
const client = ApolloClient({
cache: new InMemoryCache(),
link: ApolloLink.from([
errorLink,
new HttpLink({ uri: `http://localhost:8080/graphql`})
])
})
For now, I am finding a solution to stop propagation to top-level so that I can show only InvitationErrorPage and stop displaying error notification at the global level.

Answer 1

I was also trying to prevent errors from being logged in an Error Link by handling them on a useQuery hook and a further delve into the ApolloLink documentation helped clear up what is happening. The key misunderstanding is that the Error Link is not a parent- or application-level handler, it is request middleware. It's helpful to think about how the data is coming back from the server:
Thus, when you see an error notification from the Error Link it is not something that "propagated up" from the useQuery hook: it occurred in the request path before the useQuery result was available on the client.
Thus, the onError callback for the Error Link will always be called before any error handling code in the useQuery hook.
Probably your best bet is to use a combination of the operation and graphQLErrors[x].extensions to figure out what errors you should pass through the Error Link middleware like so:
const errorLink = onError(({operation, response, graphQLErrors}) => {
if (!graphQLErrors) {
return;
}
if (operation.operationName === "DecodeInvitation") {
for (const err of graphQLErrors) {
if (err.extensions?.code === 'UNAUTHENTICATED') {
// Return without "notifying"
return;
}
}
}
// Notify otherwise
notification.error(graphqlErrors[0].message);
})