Watir:Test Unit:What is Test Unit?

This is the simplest usage of Watir and Test::Unit that I could think of. You do not have to install anything, Test::Unit is included in Ruby.

require 'test/unit'
require 'watir'

class GoogleHomePage < Test::Unit::TestCase
  def test_there_should_be_text_About_Google
    browser = Watir::IE.start "http://www.google.com"     assert(browser.text.include?("About Google"))
  end
end

If you run this code, you should see something like this.

C:\Documents and Settings\limited\Desktop\branches_test_unit>test_unit.rb
Loaded suite C:/Documents and Settings/limited/Desktop/branches_test_unit/test_unit
Started
.
Finished in 1.687 seconds.

1 tests, 1 assertions, 0 failures, 0 errors

Using Test::Unit Assertions

Using xUnit assertions can be a more powerful way of validating test results.
Ruby has an xUnit framework called Test::Unit that we can use with Watir. Look at the Watir Examples and unit tests for executable examples. To use Test::Unit in your test scripts, enter the following in your test script:

require 'test/unit'

Create a Test Instance

We create a new class for our test suite which is inherited from the Test::Unit TestCase class.

class TC_myTest < Test::Unit::TestCase
  # fill in Test Case methods here
end

Create a Test Case Method

Within our test case class, we need to declare test cases as methods like this:

def test_myTestCase
  # fill in method body with Watir code and assertion here
end

Test case method names must be prefixed with the word test.
When we run the test script from the command line, Test::Unit uses reflection to go through our test class and execute all the test cases declared in it. The runner by default executes the test cases alphabetically, so if you need to chain test cases, prefix letters from the alphabet or numbers after the test prefix to force them to run in order. ex. test_a_mytest.
Note: If you use numbers in your method names, note that 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 will be executed in this order: 1, 10, 11, 12, 2, 3, 4, 5, 6, 7, 8, 9. Instead, use this format: 01, 02, 03, 04, 05, 06, 07, 08, 09, 10, 11, 12. ex. test_01_mytest, test_02_mytest, test_03_mytest will run in the order expected.
The test case class with test cases defined will look like this:

class TC_myTest < Test::Unit::TestCase
  def test_ myTestCase
    # Watir code and assertion here
  end
  def test_anotherTestCase
    # Watir code and assertion here
  end
  def test_aTestCase
    # Watir code and assertion here
  end
end

Use Assertions

Watir can support assertions by wrapping Watir methods within an assert:

assert(ie.contains_text("Reached test verification point.")

Watir can test for many different states of objects. We can use assertions to check of objects exists, are enabled or disabled, or any other state that the DOM tells the web browser about an object.
If you would like to chain test cases in a single Test::Unit class, and use one Internet Explorer instance, use either a class variable @@ie, or a global variable $ie. This allows the test script to use the same Internet Explorer instance for all the test cases.
Note: use global variables with caution.

Setup and Teardown

The method names setup and teardown are reserved for Test::Unit. If you would like to use setup and teardown functionality, simply use those as method names for the actions you want executed before and after executing each test case.

def setup
  # fill in code that will run before every test case here
end
def teardown
  # fill in code that will run after every test case here
end

Why are my test cases running in the wrong order?

Subclassing Test::Unit::TestCase will make your tests run in alphabetical order. Therefore in the case of this code:

class SampleTest < Test::Unit::TestCase
  def test_login
    # login test code, etc
  end

  def test_account
    # account test code, etc
  end
end

The second test, test_account, will run before test_login.
To run the tests in the order they are defined in the suite, subclass Watir::TestCase instead.

class SampleTest < Watir::TestCase
  def test_login
    # login test code, etc
  end

  def test_account
    # account test code, etc
  end
end

For more information see Test-Unit Patch page.

How to run a specific test case?

ruby my_test_file.rb --name test_account