What is white box testing

[vipulb]

Can anyone tell me what is white box testing

[The_Big_K]

Originally Posted by vipulb

Can anyone tell me what is white box testing

Good question. Here we go -

In layman's language, its about verifying the actual code. White box testing is also known as 'Glass box testing', because in white box testing, the software test engineer is expected to look behind the front end screens, i.e. the code.

Normally, the white box testing is performed by the software developers. However, if the testing engineers have the knowledge of the programming language in which the software has been developed, they can do the white box testing. White box testing is typically used in unit and integration testing.

Do read a good post on White box testing here -

What is white box testing? Need and limitations of White box or glass box testing

[viiper]

White-box test design allows one to peek inside the "box", and it focuses specifically on using internal knowledge of the software to guide the selection of test data. Synonyms for white-box include: structural, glass-box and clear-box.

[friendster7]

White box testing (a.k.a. clear box testing, glass box testing or structural testing) uses an internal perspective of the system to design test cases based on internal structure. It requires programming skills to identify all paths through the software. The tester chooses test case inputs to exercise paths through the code and determines the appropriate outputs. In electrical hardware, testing every node in a circuit may be probed and measured; an example is in-circuit testing (ICT).
Since the tests are based on the actual implementation, if the implementation changes, the tests probably will need to also. For example ICT needs updates if component values change, and needs modified/new fixture if the circuit changes. This adds financial resistance to the change process, thus buggy products may stay buggy. Automated optical inspection (AOI) offers similar component level correctness checking without the cost of ICT fixtures, however changes still require test updates.


Software Testing Portal
While white box testing is applicable at the unit, integration and system levels of the software testing process, it is typically applied to the unit. While it normally tests paths within a unit, it can also test paths between units during integration, and between subsystems during a system level test. Though this method of test design can uncover an overwhelming number of test cases, it might not detect unimplemented parts of the specification or missing requirements, but one can be sure that all paths through the test object are executed.
Typical white box test design techniques include:
Control flowtesting
Data flow testing

source:wikipedia

do check this out too..

White Box Testing - White Box Testing Techniques