callback.js

var assert = require('assert')
var weak = require('../')

describe('weak()', function () {

  afterEach(gc)

  describe('garbage collection callback', function () {

    it('should accept a function as second argument', function () {
      var r = weak({}, function () {})
      assert.equal(1, weak.callbacks(r).length)
    })

    it('should invoke the callback before the target is gc\'d', function () {
      var called = false
      weak({}, function () {
        called = true
      })
      assert(!called)
      gc()
      assert(called)
    })

    it('should invoke *all* callbacks in the internal "callback" Array'
    , function () {
      var r = weak({})
        , called1 = false
        , called2 = false
      weak.addCallback(r, function () {
        called1 = true
      })
      weak.addCallback(r, function () {
        called2 = true
      })
      gc()
      assert(called1)
      assert(called2)
    })

    it('should preempt code for GC callback but not nextTick callbacks'
    , function(done) {
      var calledGcCallback = false
      , calledTickCallback = false
      weak({}, function() {
        calledGcCallback = true
      })

      process.nextTick(function() {
        calledTickCallback = true
      });

      assert(!calledGcCallback)
      assert(!calledTickCallback)
      gc()
      assert(calledGcCallback)
      assert(!calledTickCallback)
      setTimeout(function() {
        assert(calledTickCallback);
        done();
      }, 0)
    })

  })
})

describe('callbacks()', function () {

  it('should return the Weakref\'s "callback" Array', function () {
    var r = weak({}, function() {})
      , callbacks = weak.callbacks(r)
    assert(Array.isArray(callbacks))
    assert.equal(1, callbacks.length)
  })

})

describe('removeCallback()', function() {

  it('removed callbacks should not be called', function() {
    var called = false
      , fn = function() { called = true }
      , r = weak({}, fn)
    weak.removeCallback(r, fn)
    gc()
    assert(!called)
  })

})

describe('removeCallbacks()', function() {

  it('removed callbacks should not be called', function() {
     var called = false
      , fn = function() { called = true }
      , r = weak({}, fn)
     weak.removeCallbacks(r)
     gc()
     assert(!called)
  })

})