White-box Testing – Is It Really White?
White-box testing is testing that takes into account the internal mechanism of a system or component. White-box testing is also known as structural testing, clear box testing, and glass box testing. The connotations of “clear box” and “glass box” appropriately indicate that you have full visibility of the internal workings of the software product, specifically, the logic and the structure of the code.
White box testing involves the testing by looking at the internal structure of the code & when you are completely aware of the internal structure of the code then you can run your test cases & check whether the system meet requirements mentioned in the specification document. Based on derived test cases the user exercised the test cases by giving the input to the system & checking for expected outputs with actual output. In this testing method user has to go beyond the user interface to find the correctness of the system.
There are certain advantages and disadvantages of this testing method which are as follows:
Advantages of White box testing:
- As the knowledge of internal coding structure is prerequisite, it becomes very easy to find out which type of input/data can help in testing the application effectively.
- The other advantage of white box testing is that it helps in optimizing the code.
- It helps in removing the extra lines of code, which can bring in hidden defects.
Disadvantages of white box testing:
- As knowledge of code and internal structure is a prerequisite, a skilled tester is needed to carry out this type of testing, which increases the cost.
- It is nearly impossible to look into every bit of code to find out hidden errors, which may create problems, resulting in failure of the application.
The White-box testing is one of the best methods to find out the errors in the software application in early stage of software development life cycle. In this process the deriving the test cases is most important part. The test case design strategy include such that all lines of the source code will be executed at least once or all available functions are executed to complete 100% code coverage of testing.
Both white-box and black-box testing techniques are important and are intended to find different types of faults. Simple unit faults might need to be found in black-box testing if adequate white-box testing is not done adequately. One can strive to remove as many defects as possible using white-box testing techniques when the identification of the faults is more controllable.