Grape::Entity breaks requesting a collection with a query scope will only handle arrays about grape

[bullfight]

I took some time to inspect the code for #lib/grape/entity

I see that represent expects an array of objects or a single object

    # This convenience method allows you to instantiate one or more entities by
    # passing either a singular or collection of objects. Each object will be
    # initialized with the same options. If an array of objects is passed in,
    # an array of entities will be returned. If a single object is passed in,
    # a single entity will be returned.
    #
    # @param objects [Object or Array] One or more objects to be represented.
    # @param options [Hash] Options that will be passed through to each entity
    #   representation.
    def self.represent(objects, options = {})
      if objects.is_a?(Array)
        objects.map{|o| self.new(o, {:collection => true}.merge(options))}
      else
        self.new(objects, options)
      end
    end

Would it be reasonable to add a condition to map an ActiveRecord::Relation?

[yesezra]

I'd caution against checking whether the object is an ActiveRecord::Relation – why not do the check for Enumerable? That would, hopefully, allow compatibility with other ORMs.

[amrnt]

same w/ mongoid #76

[mbleigh]

The problem with checking for Enumerable is that a Hash is also an Enumerable and a hash should not have the same behavior mapped to it. I'm open to suggestions but not entirely sure what to do to solve the issue reliably for all cases.

[mbleigh]

OK, I think I know what needs to be done. This will solve the problem in ActiveRecord and should solve the problem in any well-implemented ORM. I'm documenting this here because I don't have time to make the change and test it right now:

Grape should do a respond_to?(:to_ary) on the incoming object and call it if it exists. #to_ary should only exist on objects that can be considered an array, not objects that can be converted to an array (so Hashes, which do respond to #to_a, do not respond to #to_ary).

objects = objects.to_ary if objects.respond_to?(:to_ary)

If someone sends a pull with tests before I get to it, I will accept. This should fix #76 as well.

[simb]

I have confirmed that changing that to check for Enumerable solves the error I am having.

[mbleigh]

This should be fixed now.