First-class support for custom handlers about graphiti-rails

[richmolj]

Also relevant to the Railtie vs Mixin issue. One use case: imagine globally rescuing a NotAuthorized error with 403 and generic message. But if you're in Admin::PostsController, you want a custom error message for this internal functionality, maybe with details on who to contact to get privileges. This is another advantage to registering errors on the controller instead of globally.

[wagenet]

@richmolj I think we may still have a slight disconnect. We're not really registering handlers globally from a developer perspective. The fact that we are using GraphitiErrors.register_exception behind the scenes is an implementation detail that the developer should not have to be concerned about. My concern is to have a default handler for JSON:API (and other types that a developer may opt-in to) and it so happens that a good way to do that is to register a handler with GraphitiErrors.

The Rails approach is to directly use rescue_from for exceptions that you want to handle. I'd like to do the same and not also require the developer to call a second API (e.g. register_exception for this to work correctly).

[wagenet]

To rewrite the code in the graphiti_errors_spec.rb, something like this:

  def render_graphiti_exception(exception, handler: nil,  **options)
    raise ArgumentError if handler && !options.empty?
    handler ||= GraphitiErrors::ExceptionHandler.new(options)
    handler.log(exception)
    json   = handler.error_payload(exception)
    status = handler.status_code(exception)
    render json: json, status: status
  end

  rescue_from(CustomStatusError) { |e| render_graphiti_exception(e, status: 301) }
  rescue_from(CustomTitleError) { |e| render_graphiti_exception(e, title: "My Title") }
  rescue_from(MessageTrueError) { |e| render_graphiti_exception(e, message: true) }
  rescue_from(MessageProcError) do |e|
    render_graphiti_exception(e, message: ->(e) { e.class.name.upcase })
  end
  rescue_from(MetaProcError) do |e|
    render_graphiti_exception(e, meta: ->(e) { {class_name: e.class.name.upcase} })
  end
  rescue_from(LogFalseError) { |e| render_graphiti_exception(e, log: false) }
  rescue_from(CustomHandlerError) do |e|
    render_graphiti_exception(e, handler: CustomErrorHandler)
  end

This seems to me to be the Rails approach, so the thing to do would basically be to make render_graphiti_exception built-in.

[wagenet]

Addressed by #22