White Box Testing

Software testing is gaining more and more importance with every software developer and development company. The reason is that nowadays more user-friendly and better functionality software are being developed. So these software end up being more complex for the developer to work on. And the competition is also very fierce. So companies hire specialized software testers, who have to only test the software in every way possible by using the variety of software testing techniques available. White box testing is such a technique that is used to test software and remove bugs if any. In the next few paragraphs, you will get an overview of this technique. Make sure you also read this article on software testing - an introduction for a better insight on this subject.

What is White Box Testing?

There are two major types of software testing techniques - white box testing and black box testing. The white box testing strategy, also termed as structural, open box, glass, or clear box testing, tests a software from inside. By inside, I mean by working on the source code of the software. It interacts with the internal logic of the code. During this testing technique, all the internal errors and malfunctions of the software are detected because it tests all the data flow, control flow, information flow, and coding practices within the system. This gives the complete details of how the software will react to various input conditions internally. So for attempting white box software testing, the tester needs to have thorough knowledge of the languages, frameworks and technologies used in the development of the software.

White Box Testing Techniques

There are certain techniques used to implement white box software testing methodology. Following are the introductions to those techniques.

Unit Testing
While developing a software, the code is usually divided into groups of codes or snippets. Each of this code unit has its own individual function that contributes to the working of the entire program. The unit testing technique tests all such units in the software one by one, to ensure that each one of them is working as per it was intended to. This is the most logical approach to start testing a software, because if all the units are working fine most of the testing is done.

Static and Dynamic Analysis
In this technique, the code is analyzed line by line using certain white box testing tools, to identify errors. Static analysis involves just checking the code for coding errors without executing it while in dynamic analysis the code is checked by executing it. Then the output is tested thoroughly.

Statement Coverage
As the name suggests this technique covers every statement in the code of a software. Every statement and every line of code are two different things. In this technique, the code is executed in such a way that every statement gets a chance to execute. This brings out errors in the statements.

Branch Coverage
If you have a basic understanding of programming, you must be knowing what branching means and how important it is. It is actually an easier way of implementing any functionality. So the branch coverage tests to check if every branch of code is working fine.

Security Testing
Now that we have checked if the code is doing what it is meant to, we need to know if the code is secure. An unsecure code will lead to frequent freezing of the application and it will be vulnerable to external threats like hacking and virus attacks.

Mutation Testing
This technique is applied to a piece of code that was corrected in any of the above testing activities. It checks if the new changes render the code more functional. It also checks if these changes have any effect on any other related functions.

Black Box vs White Box Testing

Black box testing checks if the code is producing the expected outputs from different inputs. But white box testing checks if the code is working fine from inside. Black box testing is easy to perform and implement whereas white box testing is complex and time-consuming. White box testing also tests the coding abilities of the tester while black box testing strategy can also be performed by a beginner. White box testing tests the program thoroughly and is more trustworthy, but black box testing is only an overview of the external working of the program.

I hope you have acquired all the basic information on white box testing strategy and its comparison with black box testing. You can look up some white box testing examples, to get a deeper insight into the topic.