To those who read this:
- If you are a Selenium fan, be open minded and verify the claims for yourself or contact us for clarification. And again, please be open minded. You may save a lot of time for yourself and your team.
- This document is biased towards Sahi because we built Sahi. We believe what we state is true, but if you have evidence to prove otherwise, please do contact us at support@sahi.co.in.
- When we say "Not sure" or "?" it means we do not have enough information because of lack of research on our part. Please verify for yourself.
- If you want a comparison between other tools and Sahi, we would be happy to discuss it.
- If you are another tool developer/supporter, please let us know how it compares and let the world benefit from alternatives.
Sahi vs. Selenium: Comparison document
Recorder
| Selenium | Sahi |
| Works only on Firefox | Works on all browsers (IE, FF, Chrome, Safari, Opera) |
| Has trouble recording IFrames, Frames and popup windows | Can record on IFrames, Frames and popup windows |
| For Frames and IFrames, need to explicitly selectFrame | Implicit smart identification of elements even across Frames and IFrames |
| Uses XPath for identification of elements if id or name not present | Uses various algorithms to uniquely identify elements in a simple human recognizable way |
Programming Language support
| Selenium | Sahi |
| Java, Ruby, Perl, Python, C# (and may be more). | Sahi Script, Java, Ruby Sahi Script has the syntax of javascript but can interoperate with any Java code directly from script. The Java/Ruby drivers are available since Sahi V3 |
| Needs language bridges for each new feature. For example, needs java bridge to invoke Flash via ExternalAPI. | Sahi Script can directly invoke anything exposed by javascript. |
Ease of use
| Selenium | Sahi |
| Easy to start with because of Selenium IDE which is a firefox plugin. Estimated start time less than 5 minutes | More difficult than Selenium to start because it needs installation of Sahi. Estimated start time 10-30 minutes, depending on Java installation etc. |
| Deep learning curve when the need is felt to move from Selenium IDE to Selenium RC. | There is only one mode of operation for Sahi. Extremely simple to learn and use for testers |
| Knowledge of programming language required | Can achieve most automation with just functions and variables. Sahi has inbuilt APIs for most other complex tasks like data driven testing |
| Needs JUnit style of programming | Can choose your own style |
| Uses XPath based identification for elements in complex html structures or those with dynamic ids. css selectors and javascript may also be used. | Has nearness APIs like _in and _near which can help show nearness of elements. Eg. _image(“delete.gif”, _near(“username 4”)) |
| Needs waits for making AJAX work | No waits needed in 90% cases |
| Supports parallel execution | Inbuilt parallel execution. Needs only one parameter change |
Stability of scripts and ease of maintenance
| Selenium | Sahi | |
| Smart DOM Relations resilient to UI changes | No Dependent on XPath Difficult for testers to understand and debug | Yes Does not use XPaths. Uses _near and _in |
| Implicit waits for page load and AJAX: 1) Saves time 2) Keeps scripts simple 3) Reduces random failures | No Explicit waits needed. | Yes |
| Ease of adoption by a team of testers | Needs testers to know TestNG/Junit, XPaths, HTML structures, Frames IFrame knowledge, Javascript for AJAX conditional waits | Sahi abstracts out all these for the tester. |
Dependency on other tools
| Selenium – Java (Others need something similar) | Sahi |
| Needs JUnit (and optionally eclipse) to run tests | No additional tools required. Tests run from the Sahi Controller/command line/ant |
| Non persistent reporting. Needs TestNG or something similar for that | Persistent HTML reporting which can be shared via URL or file |
Stability of product and number of releases
| Selenium | Sahi |
| Started 2004(?) in ThoughtWorks | Started 2005 in ThoughtWorks |
| Version 1 took 5 years, Version 2 planned mid-2010. Moving away from original architecture to WebDriver based architecture | Current release: Version 3 Number of stable releases in 2009: 7 |
Footprint
| Selenium | Sahi |
| RC: 10.5 MB, Grid 15 MB | less than 2 .5 MB with source |
| Not sure | Runtime ~ 50MB for 3 parallel threads |
Reporting
| Selenium | Sahi |
| Needs external tools to create readable reports | Inbuilt HTML reports with click through to relevant portion of script |
Others
| Selenium | Sahi | |
| Build tool integration (ant, batch files) | Yes | Yes |
| Multiple OS support | Yes | Yes |
| Version Controllable Scripts/Code | Yes | Yes |
| HTTPS support/redirects | Not sure | Yes |
| 401 Authentication, Windows/NTLM Authentication dialogs | Not sure | Yes |
| External proxy tunneling | Yes | Yes |
| In built APIs for data driven testing | No | Yes |
| Works only with browsers | Yes | Yes |
| Needs privileged modes on browsers for operation. (Privileged is bad) | Yes | No |
| Extensible on future browsers | Depends on finding a way to use privileged mode on that browser | Yes. Very little dependency on type of browser. |
| Editor support | Has good editors in various languages | Editor support for javascript is not as good as for Java. |
Support available
| Selenium | Sahi | |
| Free support via Forums | Yes | Yes |
| Paid support available | Yes | Yes |
| Authoritative training available | ? | Yes |
13 comments:
How about stability?
Even selenium scores badly against webdriver...
Hi Felix,
Stability is something that comes up again and again. Thanks for bringing up that point.
The cause for instability generally is due to
1) Timeouts: when the server does not respond within time, the tests break. The tool should have the intelligence to wait for the necessary time. Sahi monitors page loads and AJAX and waits till activity has subsided. Selenium requires explicit waits or waits with conditions. The conditional wait is preferred but it complicates the script and demands more from the tester.
2) Scripts very dependent on UI changes. In the absence of ids, Selenium is very dependent on XPaths, which is a hassle for testers. If the tester does not tweak the XPath, the tests will be brittle. Tweaking XPath for lots of UI elements is not a trivial task and can take up valuable tester time.
Raman,
What would you recommend for Flex testing, we have a few folks using QTP with Flex add in.
Lech
Hi Lech,
We are adding support for Flex too. It will follow the same principles of Sahi so it should be simple. If your requirement is urgent, you could check out FlexMonkey. http://www.gorillalogic.com/flexmonkey
Regards,
Narayan
Selenium does use XPath but does not rely on it. Selenium has a number of different locator techniques from using IDs or Names to CSS or XPath. You can even use JavaScript if you wanted.
Selenium, like Sahi, can invoke External APIs as long as you can access them via JavaScript. It something that is widely used by Developers/Testers around the world.
Selenium 2 has implicit waits. Its something that Selenium has been lacking and was one of the things that we needed to do and have now done. Users can use the implicit wait but these will still timeout after a while because something not loading quickly can show a bug, its not that the test is brittle.
Everything else looks correct from the Selenium point of view as far as I can see.
Hi David,
Thanks for stopping by and sharing your knowledge. I have updated the post with your information.
Selenium 2 is still in alpha so I am not adding in implicit waits yet :)
Thanks,
Narayan
Does Sahi handles subdomains while testing? As i understood, selenium does not..
Hi psylence,
Yes Sahi works with subdomains. You may need to modify sahi/htdocs/spr/domainfix.js to set document.domain to the base domain.
Raman, thanks for your answer!
Btw, i have problems running Sahi on MacOS X. I've gooled and found this one: http://sahi.co.in/forums/viewtopic.php?id=36 but it not helped(
Maybe you can give some tips, thanks.
Hi psylence,
If you post your problem on the Sahi Forums (http://sahi.co.in/forums) or email us at support@sahi.co.in, we will be able to guide you.
Raman, thanks! I"m already managed to make it running finally.
Are there any plans for SAHI to support legacy Windows and/or Java applications not under a web browser?
Hi Halperinko,
Thanks for the interest.
Currently we are concentrating only on the web. We do not have plans for windows/Java apps right now.
You could have a look at White for Windows Apps, Frankenstein for Swing apps and
SWTBot for SWT apps.
Thanks,
Narayan
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