How can I make my Selenium tests less brittle? - asp.net

Question

We use Selenium to test the UI layer of our ASP.NET application. Many of the test cases test longer flows that span several pages.
I've found that the tests are very brittle, broken not just by code changes that actually change the pages but also by innocuous refactorings such as renaming a control (since I need to pass the control's clientID to Selenium's Click method, etc) or replacing a gridview with a repeater. As a result I find myself "wasting" time updating string values in my test cases in order to fix broken tests.
Is there a way to write more maintainable Selenium tests? Or a better web UI testing tool?
Edited to add:
Generally the first draft is created by recording a test in the IDE. (This first step may be performed by QA staff.) Then I refactor the generated C# code (extract constants, extract methods for repeated code, maybe repeat the test case with different data, etc). But the general flow of code for each test case remains reasonably close to the originally generated code.

Answer 1

I've found PageObject pattern very helpful.
http://code.google.com/p/webdriver/wiki/PageObjects
more info:
- What's the Point of Selenium?
- Selenium Critique
maybe a good way to start is to incrementally refactor your test cases.
I use the same scenario you have selenium + c#
Here is how my code looks like:
A test method will look like somethink like this
[TestMethod]
public void RegisterSpecialist(UserInfo usrInfo, CompanyInfo companyInfo)
{
var RegistrationPage = new PublicRegistrationPage(selenium)
.FillUserInfo(usrInfo)
.ContinueSecondStep();
RegistrationPage.FillCompanyInfo(companyInfo).ContinueLastStep();
RegistrationPage.FillSecurityInformation(usrInfo).ContinueFinishLastStep();
Assert.IsTrue(RegistrationPage.VerifySpecialistRegistrationMessagePayPal());
selenium.WaitForPageToLoad(Resources.GlobalResources.TimeOut);
paypal.LoginSandboxPage(usrInfo.sandboxaccount, usrInfo.sandboxpwd);
Assert.IsTrue(paypal.VerifyAmount(usrInfo));
paypal.SubmitPayment();
RegistrationPage.GetSpecialistInformation(usrInfo);
var bphome = new BPHomePage(selenium, string.Format(Resources.GlobalResources.LoginBPHomePage, usrInfo.AccountName, usrInfo.Password));
Assert.IsTrue(bphome.VerifyPageWasLoaded(usrInfo));
Assert.IsTrue(bphome.VerifySpecialistProfile());
bphome.Logout();
}
A page Object will be something like this
public class PublicRegistrationPage
{
public ISelenium selenium { get; set; }
#region Constructors
public PublicRegistrationPage(ISelenium sel)
{
selenium = sel;
selenium.Open(Resources.GlobalResources.PublicRegisterURL);
}
#endregion
#region Methods
public PublicRegistrationPage FillUserInfo(UserInfo usr)
{
selenium.Type("ctl00_cphComponent_ctlContent_wizRegister_tUserFirstName", usr.FirstName);
selenium.Type("ctl00_cphComponent_ctlContent_wizRegister_tUserLastName", usr.LastName);
selenium.Select("ctl00_cphComponent_ctlContent_wizRegister_ddlUserCountry", string.Format("label={0}",usr.Country ));
selenium.WaitForPageToLoad(Resources.GlobalResources.TimeOut);
selenium.Type("ctl00_cphComponent_ctlContent_wizRegister_tUserEmail", usr.Email );
selenium.Type("ctl00_cphComponent_ctlContent_wizRegister_tUserDirectTel", usr.DirectTel);
selenium.Type("ctl00_cphComponent_ctlContent_wizRegister_tUserMobile", usr.Mobile);
return this;
}
}
Hope this helps.

Answer 2

How are you creating your Selenium tests, by recording them and playing them back? What we have done is build an object model around pages so that you call a method like "clickSubmit()" rather than clicking on an id (with a naming convention for these ids), which allows selenium tests to survive many changes.

Answer 3

You may or may not be able to write tests that are resilient to refactoring. Here's how to make the refactoring less painful: Continuous integration is essential.
Run them every day or every build. The sooner it's fixed, the easier.
Ensure devs can run the tests themselves. Again, the sooner it's seen and fixed, the easier.
Keep selenium tests few. They should focus on critical path / pri 1 test scenarios. Deep testing should be done at unit test level (or jsunit tests). Integration tests are always expensive and less valuable.

Answer 4

Hooking up on any low-level concepts like XPaths, CSS Selectors or IDs for end-to-end tests is a recipe for unstable tests.
I advise using testRigor to produce tests that won't break any time you run/change/improve your application a little bit.
The code analogous to the page object one above would look like this:
enter "Peter" into "First Name"
enter "Pen" into "Last Name"
enter "US" into "Country" below "User Data"
enter stored value "email" into "Email"
enter stored value "password" into "Password"
enter "415-123-4567" into "Direct Telephone"
enter "415-123-4568" into "Mobile Number"
click "Submit"
testRigor would associate texts that look like labels with the inputs so that as soon as from an end-user's perspective your page would look the same then the testRigor scripts will be green. Here is the doc.
disclaimer: I'm a co-founder of testRigor. I co-founded it because we had those exact issues ourselves.
Hope this helps.

Answer 5

There are no innocuous changes when it comes to test automation ;)
We use the SAFS framework with Rational Robot (RRAFS) to minimize impact to our automation scripts. There's still work to maintain the application map, but the scripts remain stable for the most part. The SAFS framework sounds very similar to the method cynicalman mentions, but already packages up the generic methods you would use in your scripts.
The SAFS site says there's partial support for Selenium, so this may work for you.

Answer 6

I've found that using XPath expressions in Selenuium-RC adds alot to the robustness of a test.
I write my tests in a similar manner. The first pass is often written via the IDE/Record to get most of my page-flow and click operations. Once I've got that, I begin stepping through the test via Selenium-RC adding assertions and changing absolute widget locators to more readable and friendly Xpath expressions. (as well as documenting the test! :) )
One thing to be aware of.. if your tests are xpath-heavy, they may run a little slower in IE6 due to its poor javascript execution abilities. (I have some test suites that take almost an hour longer to execute under IE than under FF. It's managable, but just something to keep in mind when you're writing the tests.)

Answer 7

Selenium in theory has an abstraction called UI Element (the documentation is here).
The features would be
abstract locators, indipendent on the very html implementation; this would map well to the concept of component or widget of a web framework,
rollup rules, allowing to merge several commands into a single more abstract command.
I've struggled a couple of days to leverage this feature but in the end I decided to abandon it, for the following reasons:
some concepts, such as that of offset locators (think of them as parts of a component) are not fully or usefully developed;
the feature is not fully supported in formatters and the more recent the formatter the less the feature is supported, hinting that the core Selenium evolution is leaving this feature behind;
it's not fully integrated in Selenium 2.0 (WebDriver).

Answer 8

I think Xpath is the best way to ensure robust selenium tests.
I am currently working on a library to help writing xpath expressions easier.
If interested, you can check it out here:
http://www.unit-testing.net/CurrentArticle/How-To-Write-XPath-for-Selenium-Tests.html