Selenium and Selenium on Rails

1. Selenium and Selenium on Rails

2. Agenda • Overview of Selenium • 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: www.openqa.org • Getting started: • Download Selenium core off of www.openqa.org • Place the contents of the zip file on a web server in a selenium-core directory • Go to http://web-server-host/selenium-core/index.html

6. Simple Selenium Tests • Selenium understands two types of files • Tests • 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: http://www.openqa.org/selenium-core/reference.html • 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 www.openqa.org • 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: http://www.openqa.org/classes/SeleniumOnRails/TestBuilder.html

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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