CSC/ECE 517 Spring 2014/ch1a 1j sr

Background

Watir, pronounced water, is an open-source (BSD) family of Ruby libraries for automating web browsers. It allows you to write tests that are easy to read and maintain. It is simple and flexible. Watir drives browsers the same way people do. It clicks links, fills in forms, presses buttons. Watir also checks results, such as whether expected text appears on the page. Watir is a family of Ruby libraries but it supports your app no matter what technology it is developed in. Whilst Watir supports only Internet Explorer on Windows, Watir-WebDriver supports Chrome, Firefox, Internet Explorer, Opera and also running in headless mode (HTMLUnit).

Examples

Here's Watir in action. Like all ruby gems, it has to be included to be used. Including Watir gem to drive Internet Explorer on Windows

require 'watir'

Including Watir-WebDriver gem to drive Firefox/Chrome on Windows/Mac/Linux

require 'watir-webdriver'

After including it, It can be used simply. For example to start a new browser & and going to Watir's demo website:

browser = Watir::Browser.new
browser.goto 'http://bit.ly/watir-example'

For setting the value of a text field

browser.text_field(:name => 'entry.0.single').set 'Watir'

For setting a multi-line text box

browser.text_field(:name => 'entry.1.single').set "I come here from Australia. \n The weather is great here."

Their official example page has a few examples.

Watir Compared to Capybara

On their blog, Watir team makes an interesting comparison of Capybara with Watir.

Basically, there are three ways, that is, three levels of details and control, that a programmer has to simulate a browser and the actions a user performs with an app in the browser. These three ways are selenium-webdriver API,watir-webdriver API and Capybara DSL <ref> http://watirmelon.com/tag/capybara/ </ref>.

Each level has it's pros and cons. While the lower level (Selenium) facilitate more control and flexibility, the higher level (Capybara) is convenient and quick to use and get up and running. Watir is somewhere in the middle.

The author uses the analogy of buying raw animal carcass, beef cuts, and prepared meats such as sausages to show the relationship between these three ways of interaction with the app.

Let's consider an example:

Watir Compared to Cucumber

Cucumber and Watir are not comparable in the sense that they are both different tools that aid each other for the same goal simple behavior-driven unit testing of the app. As demonstrated in the example, Watir is used to manipulate the browser, while Cucumber is used to write business readable unit tests. On its website, Cucumber mentions these six steps for suing Cucumber:

1. Describe behaviour in plain text
2. Write a step definition in Ruby
3. Run and watch it fail
4. Write code to make the step pass
5. Run again and see the step pass
6. Repeat 2-5 until green like a cuke

Basically "Cucumber lets software development teams describe how software should behave in plain text. The text is written in a business-readable domain-specific language and serves as documentation, automated tests and development-aid - all rolled into one format."

In its community wiki Cucumber mentions the usage of Watir (or Selenium, a similar tool) for making transactions with the browser. So these two tools go hand in hand in order to write a complete successful automated unit test suit, one that can be readable by non-technical people as well. Consider the following example:

Example

The way Cucumber works is that after installing the gem, the steps in business readable form are stored in .feature file, and then actual steps are written in the step definitions file. As you can see in the example below, the step definitions can then use Watir to make transactions with the browser.

features/example.feature

Feature: Search In order to use Google users must be able to search for content 
  Scenario: Search for a term
    Given I have entered "watir" into the query
    When I click "search"
    Then I should see some results

features/step_definitions/example_steps.rb

require "watir-webdriver"
require "rspec/expectations"
 
Given /^I have entered "([^"]*)" into the query$/ do |term|
  @browser ||= Watir::Browser.new :firefox
  @browser.goto "google.com"
  @browser.text_field(:name => "q").set term
end
 
When /^I click "([^"]*)"$/ do |button_name|
  @browser.button.click
end
 
Then /^I should see some results$/ do
  @browser.div(:id => "resultStats").wait_until_present
  @browser.div(:id => "resultStats").should exist 
  @browser.close
end

References

<references />

• http://watir.com/
• http://watir.com/examples/
• http://watirmelon.com/tag/capybara/