ruby-on-railsrubyrestruby-grapegrape-entity

Grape error handling strategy?


I am using Grape and Rails to create a REST API. I have the basic architecture in place and I am looking for places to 'clean' things up. One of those places is the error handling/processing.

I am currently rescuing errors in the root.rb (GRAPE::API base class) file for the whole API. I format them and then send the error back via rack_response. Everything works find but the root.rb file is getting a bit bloated with all the errors being rescued and some of them have special parsing that needs to be done. I was wondering if anyone has developed a good strategy for error handling so that it can be moved out into it's own module and leave the root.rb (GRAPE::API base class) fairly lean.

I would really like to create a error processing module and define methods for each type of error, for example...

module API
 module ErrorHandler
   def record_not_found
     rack_response API::Utils::ApiErrors.new({type: e.class.name, message: 'Record not found'}).to_json, 404
   end
 end
end

Then in the root.rb file do something like this

module API
  class Root < Grape::API
    prefix 'api'
    format :json

    helpers API::ErrorHandler

    rescue_from ActiveRecord::RecordNotFound, with: :record_not_found # Use the helper method as the handler for this error
  end
end

Has anyone done something like this? I have been trying various flavors of the above strategy but I can't seem to get anything work.


Solution

  • I've come to the following solution/strategy...

    I moved all error rescuing to its own module like the following

    module API
      module Errors
        extend ActiveSupport::Concern
    
        included do
          rescue_from :all do |e|
            rack_response API::Utils::ApiErrors.new({type: e.class.name, message: e.message}).to_json, 500
          end
          .
          .
          .
      end
    end
    

    Then I simply include the errors in my base GRAPE::API class

    module API
      class Root < Grape::API
        include API::Errors
    
        prefix 'api'
        format :json
    
        helpers API::Utils::Helpers::IndexHelpers
        helpers API::Utils::Helpers::WardenHelpers
        helpers API::Utils::Helpers::RecordHelpers
        .
        .
        .
      end
    end
    

    After a lot of experimentation and a lot of other attempts not working, I think this is a fine solution and my base GRAPE::API class remains pretty lean. I am still very open to any other approaches people might have.