How to return custom GraphQL::ExecutionError by rescue_from

[michiomochi]

I want to return custom GraphQL::ExecutionError by rescue_from.
But it seems that it can not, now.

# Not work
class TestSchema < GraphQL::Schema
  rescue_from(ActiveRecord::RecordInvalid) do |error|
    GraphQL::ExecutionError.new(message: error.message, extensions: { "code" => "INVALID_RECORD" })
  end
end

# Work
class TestSchema < GraphQL::Schema
  rescue_from(ActiveRecord::RecordInvalid) do |error|
    error.message
  end
end

How do you think?

[michiomochi]

I found GraphQL::Schema#rescue_middleware.
https://github.com/rmosolgo/graphql-ruby/blob/master/lib/graphql/schema.rb#L1026

So, override GraphQL::Schema#rescue_middleware and define custom rescue middleware.

class MySchema < GraphQL::Schema
  protected def rescue_middleware
     @rescue_middleware ||= MyRescueMiddleware.new.tap { |m| middleware.insert(0, m) }
  end

  rescue_from(ActiveRecord::RecordInvalid) do |error|
    GraphQL::ExecutionError.new(message: error.message, extensions: { "code" => "INVALID_RECORD" })
  end
end

class MyRescueMiddleware < ::GraphQL::Schema::RescueMiddleware
  private def attempt_rescue(err)
    rescue_table.each { |klass, handler|
      if klass.is_a?(Class) && err.is_a?(klass) && handler
        return handler.call(err)
      end
    }
     raise(err)
  end
end

[michiomochi]

Please tell me if there is a better way. 🙏

[dhruv-shipmnts]

Please tell me if there is a better way.

Have you found any other way to do this, i am facing the same issue too.

[DamirSvrtan]

I've used the graphql-errors gem for cases like this which allows for passing extensions:

GraphQL::Errors.configure(Schema) do
  rescue_from ActiveRecord::RecordInvalid do |error, _object, _args, ctx|
    ctx.add_error(GraphQL::ExecutionError.new(message: error.message, extensions: { "code" => "INVALID_RECORD" }))
  end
end

The gem rescues on a per field basis, so that means you can still serve partial responses.

[rmosolgo]

Hi, I just merged some new error handling for the interpreter runtime which supports returning/raising custom errors: #2458

Please give it a try and let me know if you run into any other trouble by opening a new issue!