What is white box testing? What do the testers exactly do while doing white box testing?

Question

I am a manual tester and want to move further into the depths of white box testing. I do know and have experience working with black box testing, but I am pretty much in the dark when it comes to white box testing.

1. Can anyone tell me about what exactly white box tester does?
2. Do they develop code like developers? or review the codes developed by developers?
3. What are the tools they use?
4. Is automation testing considered white box testing? What is the difference between them?
5. Why is white box testing required?

Answer 1

Basically whitebox is category of test design techniques.

Mainly whitebox testing can be done at following level :

1 - Component level

2 - Integration level

3 - System level

Whitebox testing used to measure code coverage , statement coverage , branch coverage and decision coverage.

Precondition to do whitebox testing is tester must have depth knowledge of programming language , internal code of system/website and logic.

Why do White Box Testing? :

1 - Verify all combination of logical conditions and ensure its value like true/false.

2 - Verify all independent paths within a module is exercised at least once.

3 - All loops are optimum and does not doing extra looping and works under specified area.

White Box Testing helps to find bugs like :

1 - Code syntax error

2 - logical errors in code

3 - Dataflow errors

4 - Conditional errors

We say White box testing= structure-based testing and this is because it is testing about internal structure of software/web.

Whitebox tester mostly analyze and modify code and make it standardize. Also applies diff. algorithm to make code optimized. It test real logic.

Tools :

Mostly QA/Developer uses Junit , cucumber for whitebox testing automation.

More tools you can check here : Whitebox testing tools

For more information and details knowledge , you can refer ISTQB syllabus. It has great info. regarding all testing concept.

Answer 2

It depends... white box testing can vary from what helping hands mentioned above, to functional or non-functional testing done at the code level. Usually (but not always) white box testing allows you better flexibility than testing through external interfaces (UI or other) enabling more test coverage.

I am not sure about the official definition but the way I see it white box testing is about coding, whereas reviewing has a different name. This coding is best done using the same programming language and environment as the the ones used by the product, but it can be developed in other environments too i.e. python code accessing C libraries API in a DLL.

generally speaking automation development is not considered as white box testing, unless you develop it for the purpose of white box testing (even this is not entirely accurate, since you can develop the infrastructure to enable white box testing without actually white testing something).

there are the tools mentioned above, and I would start by looking at them first but you can easily write your own or abuse other tools, it all depends on your needs and the product you are testing on.

What is required ? a combination of the requirements for a good programmer and good tester, this is a big enough subject for two new questions.

Answer 3

Whitebox is a keyword used for defining a test category that is opposite to blackbox testing. The difference between the two is really straightforward:

• whitebox testing is performed with a knowledge of what there is behind the scenes. Talking about software testing it basically means you can access the source code.
• blackboox testing is performed against an interface. You know the input and evaluate the output but you are not allowed to know what happens inside the system.

In general blackbox testing is often performed by alpha and beta testers and it mainly consists of manual testing sessions, the whitebox testing indeed allows to dig deeper into the structure of the software. One of the main advantages of being a whitebox testers is having the opportunity to automate test cases and then physically locate where the tested code is failing.

Moving from blackbox to whitebox I think is a big chance for you to improve your skills on the field of software testing and you'll have the possibility to start using a lot of tools already available on the market, and many of them are free.

For giving you more detailed info about automation tools you should add some more info about the technologies are currently adopetd by your company.