browserify troubles

'use strict'

var Stream = require('stream')
var test = require('tape')
var browserify = require('browserify')

/**
 * This plugin waits until browserify is done going through the require tree,
 * then adds "SUCCESS!" to the array passed in as `results` in the options object
 */
var myPlugin = function (brow, options) {
  brow.on('bundle', function (bundler) {
    bundler.on('end', function () {
      // Mock some async work
      setTimeout(function () {
        options.results.push('SUCCESS!')
      }, 1000)
    })
  })
}

test('plugin', function (t) {
  console.log('test')
  t.plan(1)
  var brow = browserify()
  var js = "console.log('hello world')"
  var fileStub = new Stream.Readable()
  fileStub.push(js, 'utf8')
  fileStub.push(null)
  var pluginResults = []
  brow.plugin(myPlugin, {
    results: pluginResults
  })
  brow.add(fileStub)
  brow.bundle(function (err) {
    if (err) {
      t.fail('browserify errored: ' + err)
    } else {
      // setTimeout(function () {
        t.equal(pluginResults.length, 1, "plugin is done doing it's thing")
      // }, 1100)
    }
  })
})

If you run this, you'll observe that the test fails. Now notice the setTimeout I left commented out. If you uncomment those 2 lines, the test passes.