October 8th, 2009 §
If the application you are testing tends to open new browser windows using the target="_blank" technique, you might have some problems with Selenium.
One of the reasons I find Selenium a great test automation tool for the web is that it lets you easily run your test scripts on different browsers without too much effort. Most scripts will run smoothly on IE, Firefox and even on more exotic browsers like Safari, Opera and Chrome without needing browser-specific code or having to tweak the test for a particular browser. One of the few areas where you are likely to face problems is the handling of pop-up windows. If the application you are testing tends to open new browser windows using the target="_blank" technique, you might have some problems with Selenium. The standard .selectWindow() method provided by Selenium requires either a title of the pop-up window (which is often the same as the title of the main window) or a name or a variable name (which are both missing, when the window is opened using a target="_blank" link).
You will need a workaround to select such windows and unfortunately the workarounds do not always work the same for all browsers. The following code snippets might be useful if you run into the same problem. They are tested on the *chrome and *iehta Selenium modes (with Internet Explorer 7 and Firefox 3).
Here is how you can select the pop-up window which is opened after a target="_blank" link is clicked. This actually combines several hacks and workarounds, but works at the end (at least for me):
//A hack to select unnamed pop-up windows
if (browser.equals("*iehta")){
//Find out if Selenium substituted the blank target...
if (selenium.isElementPresent(
"//a[starts-with(@target,'selenium_blank')]")) {
// ...and make it notice the new window on IE
selenium.openWindow("", selenium.getAttribute(
"//a[starts-with(@target,'selenium_blank')]@target"));
}
}
String [] winNames = selenium.getAllWindowNames();
//the last one is the pop-up window we want
selenium.waitForPopUp(winNames[winNames.length-1], timeout);
selenium.selectWindow(winNames[winNames.length-1]);
And here is how you can go back to the main window after you finished working with the pop-up:
String [] winTitles = selenium.getAllWindowTitles();
selenium.selectWindow(winTitles[0]);
May 13th, 2009 §
"Do not automate buggy software."
I was thinking about the failed automation projects I’ve been involved in during the last few years and I seem to find a pattern. All those projects were very, very buggy. I realize now that you should only aim to automate functionality which is fairly stable, so that you do not expect to see a test failure in more than about 1 of 10 test runs. If you see that your tests are failing 50% of the time, then automation is not the cure for your problems. Try to find out why this is happening in the first place.
April 9th, 2009 §
"Testers get indignant when they realize that the quality tools purchased at a serious price are themselves full of bugs. Indeed, test tools are often buggier than comparable (but cheaper) development tools. Plan to test your tools and spend time finding workarounds for bugs."
The quote comes from one of the best books on software quality I have read - Lessons Learned in Software Testing
by Cem Kaner, James Bach and Bret Pettichord. Be sure to read it if you haven't already.
I can not agree more with the authors. I spend a lot of my time in test automation trying to find workarounds for issues with the tool. Some of those issues can be considered 'functional idiosyncrasies', but most are just plain and simple bugs. During my work in the field of software quality I have noticed that users are normally quite tolerant of bugs, unless the bugs block them from doing their jobs. So for me there are two kinds of bugs in the test tools - those you can find a workaround for and those you can not.
If the tool is flexible enough and you know how to use it, most of the time you can make it do what you want - like for example using keyboard shortcuts and the clipboard to read the text from an unsupported GUI control. This is one advantage of tools that offer the flexibility of a real programming language for scripting.
There are also such things, for which you can not do much except waiting for the vendor to provide you a fix, and this can take long time. A few years ago I tried to upgrade to the latest TestPartner version (it was 5.2.3 back then). After the upgrade I found that all my automated scripts were causing random crashes in Internet Explorer. I just stayed with the old version until 5.6 came out, where this problem was fixed.
April 6th, 2009 §
Recording does not work, even with IE
I realized that I was not fair in my previous test, as I used the last version of Firefox, which unfortunately is not officially supported by TestPartner. To give it a second chance, I decided to repeat the test with Internet Explorer. I re-recorded the same scenario, but this time in IE and tried to replay it.
I got a better result, but only slightly. The recorded script was able to log-in, but could not click the button to create a new mail:
The playback failed at step 12, where the tool tries to ‘Attach’ to an HTML frame, identified with ‘Name=c36gxk9p2bo3a’. Attaching to a UI control in TestPartner means simply declaring that the subsequent actions in the script will be executed within this control. c36gxk9p2bo3a is a generated name which changes each time when you enter GMail. This was the reason the script could not find the frame, when trying to replay.
If I had to code this script by hand, I would omit this step altogether. Usually it is sufficient to only attach to the browser window and not to specific frames within it. Also, I would not locate the other controls by ID and screen coordinates as the recording did in steps 13 and 14. This will likely fail too, even if the problematic step 12 is fixed.
March 16th, 2009 §
Record/Playback does not work, but we all know this, don't we?
If you have ever had anything to do with UI test automation, you should know about recording. It is an ability that most tools (commercial or open source) have - you start the recording session in the tool and then just happily click through the test scenario on the application you are testing. Meanwhile the tool sits silently and records your actions, getting ready to replay them automatically when you want to. The ability to record the UI interactions is a marketing highlight for most automation tools. There are even some tools, where recording is the only way you can create test scripts.
On the surface it can really look like the best way to automate - you will be testing manually anyway, so why don't just record your tests to replay them at a later stage? Unfortunately the view that test automation is something as simple as pressing the record button has spread widely, mostly fueled by the hype of the tool vendors.
If you do not have any hands-on experience with test automation, you might miss a very important fact about the whole thing - it is not only about creating the scripts. In fact the actual script creation rarely takes more than 20-30% of the time you invest in automation. Here is a rough outline of all the things you have to do:
- Prepare the test environment
With automation you want to have a very consistent environment, with known data and configuration, where you execute your tests. Sometimes this is not possible - maybe you have to test in a live system, or you don't control every part of the system landscape. In such cases you can succeed only if you create smart automated tests that can anticipate and cope with all the expected changes in the environment. I will write more about this topic in the future, but for now let's just say that recording is not smart at all.
- Create the test scripts
This is the actual thing that recording addresses. It might seem that it is a very efficient way of creating test scripts, however in reality it is not. You will make errors while recording (like misclicks or mistypings). Correcting those errors in recorded scripts is most often difficult or even impossible. Also if you limit yourself to just repeating recorded sequences, you will not benefit from all the good things that automation can offer compared with manual testing (like data-driven tests for example).
- Execute the scripts
Or maybe I should say try to execute the scripts. My experience shows that unless you are testing something that has a very simple UI, recording tools often fail to create working scripts out of the box, even if you have managed to ensure absolutely consistent environment for the test execution. Recording lacks the intelligence to understand what you are doing and what your actual intentions are in a complex UI.
- Analyze the results
In case you are executing recorded scripts, you will be hoping desperately that they pass successfully. In case something goes wrong (which will be most of the time), you will have extremely hard time trying to understand if it was a bug in the product, an issue with the test script or maybe a change in the application UI.
The time spent in analysis of test results is probably the greatest time-waster in test automation and you can optimize this only by having proper logging on a higher semantic level than UI interactions. Again this is something that I intend to write about.
- Update your scripts
Software changes and you will either have to adapt your tests or throw them away. With recording it is mostly about throwing away. It is true that most of the tools now provide some ways to cope with simple changes in the UI, but those are still very limited. For example if a caption of a button changes from 'New' to 'New...', in most cases you will be able to adjust your scripts. With the good tools you will have to add the '...' only in one place, no matter how many times you click the button in your test. However, imagine that this button is replaced by a context menu. Most tools will let you somehow change this in their recorded scripts, but you will have to do this change every single place where the button was clicked in your scenario. Most probably you will just want to re-record it from scratch.
If you plan to do any serious automation, do not base the choice of your tool on how well it handles record and playback. In my opinion writing tests using the scripting language (and doing it right) is the only way to make UI automation really work.
I find recording only useful when I am testing with a new UI technology or a new automation tool and I want to quickly find out how it recognizes a particular UI control. In such cases recording a few mouse clicks and then looking at the generated script can be useful.
