failing test for Dash default with proc not working with AS as_json

spec/hashie/dash_spec.rb

@@ -12,6 +12,10 @@ class DashTest < Hashie::Dash
   property :count, default: 0
 end
 
+class DashTestDefaultProc < Hashie::Dash
+  property :fields, default: -> { [] }
+end
+
 class DashNoRequiredTest < Hashie::Dash
   property :first_name
   property :email
@@ -51,6 +55,13 @@ class DeferredWithSelfTest < Hashie::Dash
   property :updated_at, default: ->(test) { test.created_at }
 end
 
+describe DashTestDefaultProc do
+  it "as_json behaves correctly with default proc" do
+    object = described_class.new
+    expect(object.as_json).to be == { "fields" => [] }
+  end
+end
+
 describe DashTest do
   def property_required_error(property)
     [ArgumentError, "The property '#{property}' is required for #{subject.class.name}."]

spec/spec_helper.rb

@@ -10,6 +10,10 @@
 require 'rspec/pending_for'
 require './spec/support/ruby_version_check'
 
+# NOTE: should this be here?
+require 'active_support'
+require 'active_support/core_ext'
+
 RSpec.configure do |config|
   config.extend RubyVersionCheck
   config.expect_with :rspec do |expect|