How To Work with Multiple Windows

The Problem

Occasionally you'll run into a link or action in the application you're testing that will open a new window. In order to work with both the new and originating windows you'll need to switch between them.

On the face of it, this is a pretty straightforward concept. But lurking within it is a small gotcha to watch out for that will bite you in some browsers and not others.

Let's step through a couple of examples to demonstrate.

An Example

First, let's pull in our requisite libraries (e.g., selenium-webdriver to control the browser and rspec/expectations & RSpec::Matchers for our assertions) and add some simple setup, teardown, and run methods.

# filename: new_window.rb

require 'selenium-webdriver'
require 'rspec/expectations'
include RSpec::Matchers

def setup
  @driver = Selenium::WebDriver.for :firefox

def teardown

def run

Now let's write a test that exercises new window functionality from an application. In this case, we'll be using the new window example found on the-internet.

# filename: new_window.rb

# ...

run do
  @driver.get 'http://the-internet.herokuapp.com/windows'
  @driver.find_element(css: '.example a').click
  expect(@driver.title).not_to eql 'New Window'
  expect(@driver.title).to eql 'New Window'

After loading the page we click the link which spawns a new window. We then grab the window handles (a.k.a. unique identifier strings which represent each open browser window) and switch between them based on their order (assuming that the first one is the originating window, and that the last one is the new window). We round this test out by performing a simple check against the title of the page to make sure Selenium is focused on the correct window.

While this may seem like a good approach, it can present problems later. That's because the order of the window handles is not consistent across all browsers. Some return in the order opened, others alphabetically.

Here's a more resilient approach. One that will work across all browsers.

A Better Example

# filename: new_window.rb

run do
  @driver.get 'http://the-internet.herokuapp.com/windows'

  first_window = @driver.window_handle
  @driver.find_element(css: '.example a').click
  all_windows = @driver.window_handles
  new_window = all_windows.select { |this_window| this_window != first_window }

  expect(@driver.title).not_to eql 'New Window'

  expect(@driver.title).to eql 'New Window'

After loading the page we store the window handle in a variable (e.g., first_window) and then proceed with clicking the new window link.

Now that we have two windows open we grab all of the window handles and search through them to find the new window handle (e.g., the handle that doesn't match the first one we've already stored). We store the result in another variable (e.g., second_window) and then switch between the windows. Each time checking the page title to make sure the correct window is in focus.

Expected Behavior

  • Open the browser
  • Visit the page
  • Find the window handle for the current window
  • Click a link that opens a new window
  • Find the window handle out of all available window handles
  • Switch between the windows
  • Assert that the correct window is in focus
  • Close the browser


Hat tip to Jim Evans for providing the info for this tip.

Happy Testing!

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