DSL, Page Object and WebDriver patterns help address issues with Selenium tests such as verbosity, lack of expressiveness, fragility, and lack of reuse. The presentation recommends a three step approach: 1. Introduce a DSL to create high-level, readable tests in the language of the application domain. 2. Implement the Page Object pattern to separate test logic from page details through page maps. 3. Divide pages into reusable elements to increase code reuse and simplify page objects. This approach results in reliable, clear, and maintainable tests that better model the application under test.

1. DSL, Page Object and WebDriver –
the path to reliable functional tests
Mikalai Alimenkou
http://xpinjection.com
06.10.2011

2. Background
• Java Technical Lead/Scrum Master at
Zoral Labs
• 7+ years in software development
• 5+ years of working by Agile
methodologies
• Expert in Agile engineering practices
• Agile coach (TDD, Testing, Planning, etc.)
at XP Injection (http://xpinjection.com)
• Organizer of Selenium Camp, JEEConf and
XP Days Ukraine conferences

3. Agenda
• WebDriver tests issues
• Step 1: DSL introduction
• Step 2: Page Object pattern
• Step 3: Page Element pattern
• Results analysis

4. When you have a hammer, everything looks like a nail
WEBDRIVER TESTS ISSUES

5. Test Components
Application Test
Driver Data
Test
Logic

6. How WebDriver Works?
Get Driver
Invoke Commands
Provide Data
Use Locators

7. Selenium Tests Issues: Verbose
By.xpath(“//input*@value=‘continue’+”)
driver.findElement(By.xpath(…)).sendKeys(…);
driver.findElement(By.name(…)).click();
By.css(“#results dip p.first”)
By.id(“greenButton”)
driver.findElements(…).size();
new WebDriverWait(driver, 30).until(…);

8. Selenium Tests Issues: Not Expressive

9. Selenium Tests Issues: Unreadable

10. Selenium Tests Issues: Fragile
driver.findElement(By.xpath("//input[@id=(//label[tex
t()='Fax']/@for)]")).click();
What is going on here?
driver.findElement(By.xpath("//div[@id='App']/div/p[4]/di
v[1]/h4[@class='Online']")).getText()
Depends too much on
page structure!

11. Even More Hidden Issues
Test code
duplication
Hard to
understand No reuse
Fewer tests Hard to
created support
Hard to Test wrong
create new things
Performance
problems

12. What is the Primary Goal?
To enable reliable stable tests we need to
separate all parts as much as possible
Reliability
Clarity
Test Test
Data Logic
Flexibility
Application
Maintainability
Driver
Stability

13. Ideal Testing Framework
Test Logic Test Data
Storage
DSL Application Driver
Technical Driver Technical
Data Storage
Application Under Testing

14. Create domain-specific language for your application
STEP 1: INTRODUCE DSL

15. Definition of DSL
A domain-specific language (DSL) is a
programming language or specification
language dedicated to a particular problem
domain, that is created specifically to solve
problems in this particular domain and is
not intended to be able to solve problems
outside it (although that may be technically
possible).

16. DSL Usage Sample

17. DEMO

18. Benefits of DSL Approach
• High-level – tests are in the language of
product management, at the user level
• Readable – product management can
understand them
• Writable – easy for developer or QA to write
new test
• Extensible – tests base is able to grow with
DSL

19. Tips and Tricks
• Use test class hierarchy or test helpers
• Use builders, visitors and other design
patterns
• Reuse domain model from application
• Some common methods move to base test
class
• Minimize usage of driver instance in tests

20. Create page map for your application
STEP 2: INTRODUCE PAGE OBJECT

21. Page Object Pattern
search order
Index
Page
Search
Page
login
search
filter
Main
Page open
see more
Details
close Page
show me like this

22. Test Architecture with Page Object

23. Components Architecture
Isolated Concepts
logic separation
Easier
support Simplicity

24. Ways to Implement Page Object
Duplicate Site Map
with Packages and
Classes
Move Site Structure
to UI-Element

25. WebDriver Page Object Support

26. DEMO

27. “Ideal” Page Object in WebDriver

28. Tips and Tricks
• Allow chain invocations
• Basic page with driver details and common
methods
• Use already included Page Object classes to
simplify pages creation
• Expose only what is allowed to see or do on the
page
• Don’t use driver instance in tests at all
• Use static analysis to check rules
• Use site map to prepare Page Objects

29. Divide pages on reusable elements
STEP 3: PAGE ELEMENTS

30. Page Consists of Elements
Menu
Checkbox Panel
Link
List of Items

31. Different Page Elements
Checkbox TextBox Button
• click • type • click
• isChecked • hasValue • doubleClick
• check • focus • clickAndWait
• uncheck • clearText • …
• … • typeAndReturn
• isEditable
• …
Table Items Menu Panel Form

32. Why Page Element Pattern?
Highest
Clear page
level of
structure
code reuse
Building
Reliable
pages from
tests
components

33. Inversion of Control
Hides the details of
browser communication After
Before
Expose methods for what
test can see and do

34. DEMO

35. Tellurium Project

36. Tellurium Basics: UI Module
Groovy File
Can Build XPath in
Runtime
All
Elements
Element UID Isolated
Locators
Available
Actions

37. Tellurium Basics: UI Object
• uid – unique in UI module
• namespace – for future extension
• locator – locator of the UI object
– A base locator (relative XPath)
– A composite locator (object attributes)
• group – applied to some kinds of UI objects to
switch on grouping locating
• respond – define JavaScript events the UI object
could respond to
• some basic methods –
isElementPresent, isVisible, isDisabled, waitForEle
mentPresent, getText, mouseOver, mouseOut, ge
tAttribute

38. Tellurium IDE and TrUMP

39. DEMO

40. Tips and Tricks
• Create elements when first need them
• Review and improve elements continuously
• Isolate and hide hacks inside elements
• Use open source libraries as basis
• Use annotations and other metadata
techniques to simplify creation

41. What we have at the end of long way?
RESULTS ANALYSIS

42. Long Path Bring Us to…
• Reliable tests
• Reusable test code
• Separation of concepts
• Expressive tested UI structure
• Short and clear tests
• Tests look more like acceptance tests
• Tests are understood by non-technical people

43. Company DSL Library
Components may be reused between different
applications and projects inside a company
Company AJAX
Portal Components
Online Store Basic
Components
Customer
Service JSF
Components

44. @xpinjection
http://xpinjection.com
mikalai.alimenkou@xpinjection.com