[chai]The ChromeDriver could not be found on the current PATH

在使用 chai 的 webdriver 時出現了一點問題，其 demo code 如下，基本上同官方網站:

// test/index.js
var sw = require('selenium-webdriver');
var chai = require('chai');
var chaiWebdriver = require('chai-webdriver');

// Start with a webdriver instance:
var driver = new sw.Builder()
  .withCapabilities(sw.Capabilities.chrome())
  .build();

// And then...
chai.use(chaiWebdriver(driver));

// And you're good to go!
driver.get('http://github.com');
chai
  .expect('#site-container h1.heading')
  .dom.to.not.contain.text("I'm a kitty!");

然而在執行的時候出現這個問題:

node test/index.js
XXXX/node_modules/selenium-webdriver/chrome.js:54
        'http://chromedriver.storage.googleapis.com/index.html and ensure ' +
                                                                            ^
Error: The ChromeDriver could not be found on the current PATH. Please download the latest version of the ChromeDriver from http://chromedriver.storage.googleapis.com/index.html and ensure it can be found on your PATH.
    at Error (native)

而且其實我的 chromeDriver 已經是最新版了...

後來在 stackoverflow 找到了這個解法，還蠻有用的:
http://stackoverflow.com/questions/27733731/passing-requirechromedriver-path-directly-to-selenium-webdriver

修改結果如下:

var sw = require('selenium-webdriver');
var chai = require('chai');
var chaiWebdriver = require('chai-webdriver');

// Start with a webdriver instance:
var chrome = require('selenium-webdriver/chrome');
var path = require('chromedriver').path;

var service = new chrome.ServiceBuilder(path).build();
chrome.setDefaultService(service);

var driver = new sw.Builder()
    .withCapabilities(sw.Capabilities.chrome())
    .build();

// And then...
chai.use(chaiWebdriver(driver));

// And you're good to go!
driver.get('http://github.com');
chai
  .expect('#site-container h1.heading')
  .dom.to.not.contain.text("I'm a kitty!");

FYI.