Dash defaults not working with ActiveSupport's as_json

[joevandyk]

I'm not sure if this is a Hashie or ActiveSupport problem. I would expect fields to be an array, not a hash when as_json is used. It works fine if I don't use a proc for the default.

require 'active_support'
require 'active_support/core_ext'

class DashTestDefaultProc < Hashie::Dash
  property :fields, default: -> { [] }
end

describe DashTestDefaultProc, :focus do
  it do
    object = described_class.new
    expect(object.as_json).to be == { "fields" => [] }
  end
end

DashTestDefaultProc
  should be == {"fields"=>[]} (FAILED - 1)

Failures:

  1) DashTestDefaultProc should be == {"fields"=>[]}
     Failure/Error: expect(object.as_json).to be == { "fields" => [] }
       expected: == {"fields"=>[]}
            got:    {"fields"=>{}}

[dblock]

Looks legit. You should PR a (failing) spec.

[joevandyk]

done in #363

[sazor]

I found what causes this problem. Proc is evaluated first time only when property is directly called. #as_json method from active_support doesn't get values but just goes through hash using #map and call as_json for each value. So it tries to call as_json in Proc, it isn't defined and because of it uses as_json of Object which leads to collect its instance_variable and return {} since there is no variables. I see two ways of solving it: evaluate proc in time of initialization or monkey patch something (add as_json method to Proc or do something with ActiveSupport patches).

[dblock]

I'm against monkey patching FWIW ;)

[sazor]

Maybe default procs should be evaluated when object is initialized? Method #values also returns procs and i think it's weird because #[] and #values should return same values.

[dblock]

I am not sure @sazor, try to PR something and we can see what specs that breaks ;)

[dblock]

Closed via #380.