Friday, August 20, 2010

Knowing the bug

Testing involve many activities like finding issues,reporting status,exploring,understanding  your application and may be more. Among all I personally like  debugging or troubleshooting the bug. Some people might say that it is not tester's job and tester's job is to just report the issue. I don't want to argue on that but I would like to say that knowing and finding root cause of bugs help me in following ways,

-That experienced can be used when you test similar set of application.
- If you are aware that you are going to hit same bug with newly design feature, you can very well give your input at design time.
-You will get to know more about internals of AUT, which will help you to isolate bugs  and make your bug report stronger.

I love to find the root cause of bugs  before reporting the bug. I have developed some debugging experience  but if some new features going to come I always like to question developer. Question will be "How they will go about debugging if they found some bug in the new feature". We can use that information as much as possible until it is not that related to code debugging. I would like to put some debugging experience with web application which can be used in general. I also use this technique to isolate bugs. Suppose you hit issue while testing web based application.

-First thing will be to divide it in two parts. Issue can be either server side issue or client side issue .
Server side debugging can be started started with server logs. There can be two types of server logs for web based application
  • Web Server logs :-Sometimes these logs are useful to identify what type of HTTP request is coming to server. There are status code for each type of HTTP response, So if your application works over HTTP then status code can help you to check if every request coming from client is fine. You can make out from this logs that issue is client side or server side.
  • Application server logs :- Logs generated by application and often Application server  logs + Web server logs are combined to form one log. Logging in debug mode helps to find out any exception or error. Exceptions throws stack trace, which highlight origin of error. You can follow the stacktrace and if you have little bit idea of the code you can find the actual root cause of issue.
If you cannot find issue in server side then you can try debugging in client side.For web based client side application you will find most issues related to javascript.To debug that
-Firefox has Error console or you can use Firebug as Firefox extension, which gives fare amount of understanding of script errors.
-Chrome comes with embedded developer tools for debugging javascript errors.

It is always good to question your developers about debugging. Tester are the one to see the issues in first place, so they can be one of best person to debug and this can help you avoid getting "bug not reproducible" responses  from development.


  1. If you are in the space of debugging/testing SOAP based web application/services, then a tool like soapui comes very handy.

  2. Thanks Jinu for your input.I would like to try that.One more thing related to SOAP is if application based on mono/.Net then it provide .asmx file which can be accessed through any web browser. I use to debug with that till now in one of my project.