Selenese (Selenium scripting) in node: experimenting with a DSLish interface to WebDriver. Can connect to saucelabs or a local server or other Selenium installation. Looks sync but is heavily async, lots of talking via WebDriver.

persona-login-sequence.js

const assert = require('referee').assert
    , refute = require('referee').refute
    , fail   = require('referee').fail

// magic pixie dust to get us initialised
const $ = require('selenese_node/sequence')(module)

const loginEmail = 'testmystuff@mockmyid.com'

// some state to maintain along the way
var mainWindow
  , personaWindow

// GO!

$.title(/some title regex here/i)

$.windowIds(function (ids) {
  assert.equals(ids.length, 1, 'just have one window open')
  mainWindow = ids[0] // save state for later
})

$.click('.persona-identify')

// function for this implemented below, simple helper because this is
// done twice
waitForWindowIdCriteria(function (ids) {
  if (ids.length > 1) {
    personaWindow = ids.filter(function (id) {
      return id != mainWindow
    })[0]

    // we can sub-queue additional interactions within calls to create a
    // hierarchical async call structure, execution won't continue until
    // this call
    $.selectWindow(personaWindow)

    return true
  }
  return false
})

// now we're in the persona popup window

$.waitForVisible('#authentication_email', 30 * 1000) // timeout will cause a fail

$.wait(1000) // I don't know why we need to wait here, but I blame persona...

$.type('#authentication_email', loginEmail) // enter some text

$.click('.buttonrow .isDesktop.isStart.isAddressInfo') // click a button

// wait for only one window, i.e. the persona window ought to disappear
waitForWindowIdCriteria(function (ids) {
  if (ids.length == 1) {
    $.selectWindow(ids[0])
    return true
  }
  return false
})

// and back at the main window, checking for a proper login

$.waitForElement('.signed-in a', 20 * 1000)

// this would tell us that we're logged in because the page has our email

$.textPresent('.signed-in a', loginEmail)

// and here we end!

$.wait(function (next) {
  console.log('waiting 1s before we finish, for no good reason')
  setTimeout(next, 1000)
})

// utility $.wait() function

function waitForWindowIdCriteria (criteria) {
  $.wait(function (next) {
    function windows () {
      $.windowIds(function (ids) {
        if (criteria(ids))
          return next()
        setTimeout(windows, 100)
      })
    }
    windows()
  })
}

runner.js

// execute the sequence with this invocation

const run             = require('selenese_node/run')
    , personaSequence = require('./persona-sequence')

run('http://localhost:3000' , { browserName: 'firefox' }, personaSequence)

the problem with just var _ = sequence.create() is that I need to return something, but you're right, it's boilerplate overhead and I need to remove it somehow.