Representations cannot be serialized/cached

[esoto]

Hey guys! I'm having an issue using Grape with cache (Garner) and send the results with grape-entity.

The issue is: the second time I request an object Garner start working, but the call for Grape Entity have a problem, because it sets the options as nil, making grape-entity to throw an error, options is not define.

Versions Grape 0.6.1 Grape-entity 0.4.0 Garner 0.3.2

[dblock]

Can you show some code please? What options?

[esoto]

well the options variable which is nil is present on the line https://github.com/intridea/grape-entity/blob/master/lib/grape_entity/entity.rb#L394 and actually the error is because the merge can't be done to a nil object

the controller looks like this

route(:get, ':id') do
  cache(bind: { klass: ClassName, object: { id: params[:id] } }) do
     # Some validations
     object = Object.find_by_id(params[:id].to_i)
     Object.represent(object,  :uri=>"some_uri")
  end
end

[dblock]

I see. I think the real bug is that a representation cannot be cached (serialized/deserialized). It would be helpful if you could build a failing test within grape-entity's RSpec tests that describes that.

As a workaround you could serialize the JSON if that's your only format, for example, which is probably better anyway for performance, so:

route(:get, ':id') do
  cache(bind: { klass: ClassName, object: { id: params[:id] } }) do
     # Some validations
     object = Object.find_by_id(params[:id].to_i)
     Object.represent(object,  :uri=>"some_uri").as_json
  end
end

[esoto]

It's a tradition on the team to give an ice cream for a fix like this, so we own you!! haha We'll use for now the workaround, but I'll make the test for this scenario in my free time.

Thank you very much.

[dblock]

So that .as_json worked, right?

[esoto]

kind of late, but yes it does worked