Display error message from server on introspection errors

[sproctor]

Use case

When Supabase encounters a malformed comment, it returns an error to introspection requests. It would be nice to see that error.

Describe the solution you'd like

Currently when the server has an error, ./gradlew downloadServiceApolloSchemaFromIntrospection displays this message:

java.lang.Exception: Introspection response from http://127.0.0.1:54321/graphql/v1 can not be parsed

The response from the server was:

{
  "data": null,
  "errors": [
    {
      "message": "invalid input syntax for type json"
    }
  ]
}

In that case, it would be nice if Apollo gracefully handled the error and displayed the message from the server.

[BoD]

We could certainly improve the message. Passing --stacktrace to the gradle invocation does show more info but only the first 50 characters of the received document are shown.

[sproctor]

Thanks! I did run it with --stacktrace, but I didn't notice that the message was actually in the output.