Friday, June 26, 2009

checkbox margins in IE incorrect

By default, checkboxes have some margin and perhaps padding so they take up a bit more space than is needed. I needed to make some checkboxes take up the least amount of space possible, and the following css:

input {

didnt work in IE6 and IE7, while working perfectly in firefox (as usual).


Add the following IE only css:

<!--[if IE]>
<style type="text/css">
input {
margin: -5px;

This fixes the problem on IE6, and IE7, i dont know if IE8 has this problem or not.

Monday, June 22, 2009

Scroll bars not working and MSThemeCompatible

I recently had a problem where scroll bars were not working properly when windows XP was themed in the default theme (not classic). The scroll bar would not move if one used the arrows, or clicked in the area between the bar and the arrows. It could still be used by dragging it up and down.

The weirdest part of this issue was that the scroll bar worked normally in the windows 'classic' theme, but would seize to function correctly if you switched themes over to the ugly blue default theme.

I should also add that this scrollbar was part of a javascript widget where its position determined position of another DIV in the widget.

Solution (Hack):
Before i found the proper solution i came with a hack - on page load, add 1px to the width of the scrollbar and change its css left to -1px like so (this is jQuery):

$scrollY.css({"position":"relative", "left":"-1px"});
$scrollY.width($scrollY.width() + 1);

This seemed to work for some reason, the scrollbar works after this is applied.

I later stumbled on another solution that didnt smell like such a hack, but i am not sure what side effects it has other then making the scrollbar work. The solution is to set an a meta tag in IE only (because firefox has a bug with this metatag):

Monday, June 08, 2009

Tellurium: A Better Functional Test

Lets face it, Selenium has been around for years, it has been a choice tool for functional testing for many because it is free, has good support, and it works. Sure, it hasnt seen many updates as some would have liked, for example it didnt have firefox 3 support for a very long time. No big deal right? The latest beta supports firefox, and every one knows how to use it, the feature set has remained pretty much unchanged for years.

Why would you want to break the mold of functional testing and try something new? Well, until very recently, there hasn't been a compelling enough reason to do this. Fortunately, now there is: Tellurium.

Tellurium is another open source functional testing framework that picks up where Selenium has left off, and packs many new great features. The ideas themselves aren't exactly new: caching, UI modules, DSLs to describe the UI, Data Driven Testing, Using a JS framework instead of xpath, just to name a few. These ideas have been around for ages, but never before have they all been implemented in a mature functional testing framework.

This is the reason you should try Tellurium: new features, and the speed of their implementation.
I didnt know what i was missing with selenium until I implemented a few test cases using Tellurium's UI mapping Groovy DSL. This was a year ago, and I took a gamble in a fairly young testing framework based on Selenium server. Let me tell you, it has paid off. Not only are my tests written in a more Object Oriented way, but since upgrading to Tellurium 0.6.0 my tests run faster.

Lets look at some benchmarks.

Right now Tellurium is built on top of Selenium server, it translates its calls into one or more Selenium calls to do it job. Selenium uses xpath as its primary selector, while Tellurium also supports using the sizzle selector engine, in its jQuery selector.
The following graph shows the sizzle engine speed versus the default xpath engine using by Selenium. The blue is the xpath execution speed, and the red and yellow is jquery without caching and with caching, respectively.

As you can see, the speed up from using siggle is about 30%. I should add that this benchmark was taken on IE6, the slowest javascript platform that is still supported by most sites.

This speed up is going to allow you to have more time to do other things, or write better test cases. It can greatly speed up continuus intergration tests.

For more information about caching see this page. For more information about jquery selector see this page.

Another big performance booster in tellurium 0.6.0 is the bulk data retrival that is possible when using jquery. Every one who has used jquery knows about the convenience of $("table td").text(). Tellurium now performs such calls if you ask it for the text of of all cells in the table, whereas selenium will get you that data cell by cell with overhead for every call.

The above graph shows the awesome speedup that is possible with bulk data retrival. Notice the rightmost group titled "Bulk Data". The yellow bar representing Tellurium performance is so small that it seems like it may be missing. In this case, the speedup from gathering all the data in the javascript, and transporting it in one call gives you an incredible speed up of a few 1000%.

Upcoming performance Improvements in 0.7.0

One nice thing about Tellurium is the speed of development, and new features that make it into the build.

I have been keeping an eye on a performance improvement called "Control Group". The idea behind control group is to group together Selenium server calls into groups, execute them, and return multiple data sets. Since the biggest overhead comes from interacting with the server, this will be a big improvement over the current situation.

So, try tellurium out, you wont be disappointed.