therubyracer/specmem/proxies_memspec.rb

require 'spec_helper'

describe V8::Portal::Proxies do
  include V8::MemSpec
  
  context "A Ruby object embedded into JavaScript" do
    it "holds a hard reference to any ruby object which is linked to a javascript proxy" do
      rb_object = Object.new
      check_not_finalized(rb_object)
      subject.register_javascript_proxy c::Object::New(), :for => rb_object
      rb_object = nil
    end

    it "releases the hard reference if its corresponding javascript object has been garbage collected" do
      rb_object = Object.new
      js_proxy = c::Object::New()
      check_finalized(rb_object)
      subject.register_javascript_proxy js_proxy, :for => rb_object
      rb_object = nil
      ruby_gc do
        v8_gc()
      end
    end
  end

  context "A JavaScript object embedded into Ruby" do
    it "holds a hard reference to any JavaScript object which is linked to a Ruby proxy" do
      js_object = c::Object::New()
      check_not_finalized(js_object)
      subject.register_ruby_proxy Object.new, :for => js_object
      js_object = nil
    end

    it "clears any strong references to the JavaScript object when it's Ruby proxy is garbage collected" do
      js_object = c::Object::New()
      rb_proxy = Object.new
      subject.register_ruby_proxy rb_proxy, :for => js_object
      check_finalized(js_object)
      js_object = rb_proxy = nil
      ruby_gc do
        v8_gc
        GC.start
        v8_gc
      end
    end
  end
  private

  def finalize(object_id)
    @finalized ||= {}
    @finalized[object_id] = true
  end

  def check_finalized(object)
    @finalized ||= {}
    ObjectSpace.define_finalizer(object, method(:finalize))
    id_to_check = object.object_id
    object = nil
    afterwards do
      @finalized[id_to_check].should be_true
    end
  end

  def check_not_finalized(object)
    @finalized ||= {}
    ObjectSpace.define_finalizer(object, method(:finalize))
    id_to_check = object.object_id
    object = nil
    afterwards do
      @finalized[id_to_check].should be_false
    end
  end

  def afterwards(&block)
    @after ||= []
    @after << block if block_given?
  end

  after do
    ruby_gc do
      @after.each do |proc|
        proc.call
      end if @after
    end
  end
end