Specific GraphQLError when handling exceptions in a SpringGraphQLContextFactory

[j-davies]

Hello,
I have a SpringGraphQLContextFactory that decodes a jwt token, at the moment if the token is invalid a 500 error is returned to the client.

I would like to send a GraphQLError AuthenticationError with code UNAUTHENTICATED in a similar way to Apollo Server allows.

I cannot send a GraphQLError directly from the context, because it does not have access to the response.
I have looked at using at DataFetcherExceptionHandler, but that is only invoked on exceptions that happen during the graphql request excution.
Also, I looked at creating my own SpringGraphQLServer and handling specific exceptions with a custom error, but this is a bit messy.
A specific error could be returned if moved the token validation into the Query/Mutation, but I would like to have it all handled transparently in the Context.

What would be your recommended approach?

[dariuszkuc]

Hello 👋
With the recent server refactor (#988) you could create custom instance of GraphQLServer that would handle the exception thrown directly from the SpringGraphQLContextFactory and return appropriate response. This is available in version 4.0.0-alpha.11+. See wiki for details.

In older versions you would need to create your own custom ContextWebFilter that would send the error on the ServerWebExchange.