Micronaut GraphQL: How to respond with a non-200 HTTP status code from within GraphQL handler?

Question

Following the docs and here's my exception handler (Kotlin):

@Produces
@Singleton
@Requirements(Requires(classes = [ForbiddenException::class, ExceptionHandler::class]))
class ForbiddenExceptionHandler : ExceptionHandler<ForbiddenException, HttpResponse<*>> {
    override fun handle(request: HttpRequest<*>, exception: ForbiddenException): HttpResponse<*> {
        return HttpResponse.status<String>(HttpStatus.FORBIDDEN, exception?.message)
    }
}

Throwing a ForbiddenException from within my GraphQL handler bubbles the message into the response body, but the status code is always 200.

Example response:

{
  "errors": [
    {
      "message": "Exception while fetching data (/createUser) : FORBIDDEN",
      "locations": [
        {
          "line": 2,
          "column": 3
        }
      ],
      "path": [
        "createUser"
      ],
      "extensions": {
        "classification": "DataFetchingException"
      }
    }
  ],
  "data": null
}

Micronaut version: 1.3.3 Micronaut GraphQL version: 1.3.0.RC1

Answer 1

Disclaimer: GraphQL is not REST. You are here asking a question related to the core foundation of graphql specification (and any implementations of graphql in general).

They made the choice to embed most errors encountered in the execution of the queries but yet always return a 200 HTTP status. Therefore, you won't be able to change that in your project. It is not a configuration of graphql-java.

The good news is that the format of errors is known. Therefore, you are able to deserialize the error return payload in your application and handle correctly any error that would be thrown by graphql.

Please have a look at this link for in-depth explanations about the main difference between REST and Graphql.