Test All The Things

March 27, 2014
Tools PowerShell Testing Psate WatiN .Net

This is a follow-up to my last post on using PSate for test automation. I demonstrated running Invoke-WebRequest and validating the StatusCode as a simple test for if a site is available. Now let’s take it to the next level and run an artificial transaction. Again, PSate is a handy test runner to manage this and the open-source project, WatiN (pronounced as What-in) is a great tool for automating a real browser.

Here is the full script. https://gist.github.com/cdhunt/9809635

I also want to mention FluentAutomation as another good .Net web testing automation framework. For reasons probably irrelevant to you, I went with WatiN.

So, taking a look at this script, the first line is pretty obvious. Load up the WatiN library. If you are unfamiliar with the syntax of the next four lines, that is simply creating a type accelerator for WatiN.Core.Find to save me some typing later on. PSate supports TDD and BDD style tests. In the last post I used TestFixture and TestCase and in this one I use Describing, Given and It. For the purpose of this use case, they are interchangeable.

It takes very little effort to start automating a browser with WatiN. $ie = New-Object WatiN.Core.IE('http://www.bing.com/') will start up an instance of Internet Explorer and browse to the provided URL.

The next part has a few things going on.

$ie.TextField([Find]::ByName('q')).TypeText('Automated Ops')

The TextField method returns a TextField object representing a given page element. In that we use the ByName static method to search the page for an element with the name ‘q’. This is where creating the custom type accelerator comes in. Without it you would have to type the fully qualified namespace of the class, such as [WatiN.Core.Find]. It’s basically an alias for a .Net class. Then call the TypeText method on the TextField object to actually type some text into the Bing search textbox.


A bit of the same, but this time finding a button and calling the Click method.

Then we define a test.

It 'Contains "Automated Ops"' {
  $ie.ContainsText('Automated Ops') | Should Be $true

The browser object has a method that wills search all of the contents of the page for a given string and return $true if there is a match. Check that the results are indeed $true and be sure to Close() the browser at the end of your tests. The logic within the Contains block, both above and below the individual tests, will actually be called for each test (each “It”). That will produce a fresh browser session for every single test. That’s important so one test doesn’t break all subsequent tests and something you need to be aware of when writing test cases—There is no shared session between tests. If you want that, move the browser object instantiation to the Describes block.

When Invoke-WebRequset isn’t enough, it is still pretty easy to take web access automation to the next level.

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