1. Selenium and Selenium on Rails

2. Agenda Overview of Selenium Overview of Selenium on Rails
Simple Selenium Tests
Selenium IDE
Overview of Selenium on Rails
Problems with Selenium

3. Selenium Overview Selenium is composed of four things: Selenium Core
Selenium IDE
Selenium RC
Selenium on Rails

4. Overview of Selenium
Open source browser based integration test framework built originally by Thoughtworks
100% Javascript and HTML
Designed to make test writing easy
Ability to run whole suites of tests or individual tests
Ability to step through individual tests
Cross browser – IE 6/7, Firefox .8+, Opera, Safari 2.0+
Lets see an example of a selenium test suite…

5. Overview of Selenium
Downloads and Documentation can be found at:
Getting started:
Download Selenium core off of
Place the contents of the zip file on a web server in a selenium-core directory
Go to

6. Simple Selenium Tests Selenium understands two types of files
Test Suites
Every test must be contained within a test suite
Both tests and test suites are defined by using simple tables in HTML
To execute a test suite you must point TestRunner.html at it

7. Format of Selenium Test Suite
More complex than Selenium Tests
Easiest just to copy TestSuite.html from the samples
Mostly a table that points to the tests

8. Format of a Selenium Test
HTML Table with 3 columns
First Column: Selenium command
Second Column: Required first parameter
Third Column: Optional second parameter
Selenium commands are broken into 3 types:
Actions – Command the browser to do something
Accessors – Store/retrieve data from selenium variables
Asserts – Verify that the browser is in a certain state

9. Format of a Selenium Test
Two types of Selenium Parameters
Locators – Used to find elements in html trees
Pattern Matchers – Used to verify values
Lots of locator types. Some examples are: Id based, xpath based, css selector based
Pattern matchers are typically exact matches or regular expressions
Lots more info at:
So lets try to write a simple Selenium test…

10. Gotchas in HTML Selenium Test Writing
Selenium is sensitive to the format of the table
All selenium command rows must have three columns or they will not be recognized as commands
You can only test URL’s that are in the same domain as the selenium core
Separation of concerns is hard – Tests become very dependent on the internal structure of the HTML

11. Wow, that was hard! Lesson learned: Never ever write this by hand
There are a lot of commands - you can even add your own custom commands into the user-extensions.js
Firebug is very useful for developing your accessors

12. Selenium IDE
Firefox extension that allows recording and editing of tests
Can be download off of
Allows easier development of tests
Can even output Ruby for it’s Ruby based API
Lets see it in action…

13. Selenium IDE Much easier to use
Only really works with synchronous requests
Only automates commands, assert still must be entered by hand
Still requires lots of work to get Selenium to run it as part of a Test Suite

14. Selenium on Rails
Plugin for Rails that allows tests to be expressed in Ruby
Selenium core files no longer go in public – they are part of the Plugin
Supports two kinds of files SEL files and RSEL files
SEL files are pipe separated files that look much like Selenium HTML
RSEL files talk to a Ruby API that closely mirrors the normal commands – more info at:

15. Selenium on Rails
Each test becomes a single RSEL file which contains Ruby calls closely resembling the Selenium Commands
RSEL files work much like views in Ruby and can be broken down into partials
Selenium on Rails takes over the /selenium/ URL space
RSEL files are used to automatically generate Selenium HTML table based tests
Selenium on Rails then generates it’s own Test Suite containing all of the tests

16. Selenium on Rails
RSEL files can reference fixtures and clear session state on startup
RSEL files support partials
Test development is much more Rails like -> Edit RSEL file, hit Reload in browser, run updated test
Lets see it in action…

17. That was still pretty hard…
Selenium on Rails does not initially make WRITING tests any easier
Selenium on Rails makes deploying and the development cycle of tests easier
Selenium on Rails makes writing tests more natural for RoR developers – it also gives your tests access to the rest of the code you have developed for your application
Selenium on Rails should really be seen as a starting point for developing a DSL to test YOUR application

18. Problems with Selenium
The Xpath locators are basically worthless because of the poor performance in IE
It is not designed to do AJAX type testing
waitForElement and waitForCondition are the tools that Selenium provides to deal with AJAX both of which add a lot of complexity to tests
Custom Selenium commands added to user-extensions.js are difficult to write – Avoid doing so unless you must
Timeouts are unreliable – sometimes tests hang
Not all Javascript events are supported

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