Also known as ‘Structural testing’, it elementally involves dissecting the software code structure. Once the product’s internal structure becomes understandable, tests can be carried out to ensure conformity of internal operations as per specifications.Various testing methodologies involved:
The testing involves checking the coherency of the code specifications. In the segment coverage section, the execution of each code statement once is ensured. In the compound condition testing, multiple conditions are tested to ensure adequacy of every condition involving multiple paths and the suitability of the path combinations for reaching a desired condition. In the basis path testing, code’s every independent path is taken up for testing.
In the ‘Data Flow Testing’ methodology, the specific variables are tracked through various calculation modes. This defines the range of intermediate paths that exists in the code. The dependencies are reflected through this testing method. The thrust is on seeking intermediate dependencies through data manipulation series. The verification of use of every data variable is done. The bugs are unearthed with this method. Possible examples of bugs include non-initialized variables used in code and declared variables not used in codes.
Path testing, which is a tedious job, involves checking the entire array of paths that have been defined within the code. Loop testing is used for checking loops which may be single, concatenated and nested. This method also tests code loops which may be dependent and independent.
The need for White Box Testing
This testing is carried out to assess the exercising of the entire array of independent paths within a code module for a minimum of one instance. Further, it is verified that the entire logical decisions in the code have been verified based on outcome of true and false sequences. The testing also checks the validity of internal data structures based on their execution within pre-defined operational limits.
This testing discovers bugs in the form of logical errors which might have inadvertently slipped in the code during designing and implementation of conditions, functions and controls and may be extraneous to the software. The errors in designing which might have crept in due to discrepancies in the program’s logical flow and the final implementation are also unearthed.
White Box testing also checks the syntax errors and typographical factors in the software’s overall structure.
White box testing is an effective software testing method that essentially brings to the fore loopholes in the programming logic.