Software Test Case Design Methods - White Box Testing Methods

Software is tested in two ways:
- First approach is test the internal workings of software. It is also called white box testing.
- Second approach is to test the software as a whole, i.e., know how the software works and tests if it conforms to the specified functionality in the requirements. It is also called black box testing.

White Box Testing Techniques

It is a test case design technique that uses the internal control structure of the software component. It is also called glass box testing. It ensures that no logical errors, incorrect assumptions and typographical errors have been missed. The test cases that are included are testing all logical conditions, loops, independent paths, internal data structures. Techniques involved are:

- Basis Path Testing
It enables the test case designer to derive a logical complexity measure based on the procedural specification of a software component.
STEP 1: Use a procedural specification as input in deriving the basic set of execution path.
STEP 2: Draw the flow graph of the procedural specification.
STEP 3: Compute for the complexity of the code.
STEP 4: Determine the basic set of execution paths.
STEP 5: Document the test cases based on the identified execution path.

- Control Structure Testing
A white box testing technique that tests three types of program control - condition testing, loop testing and data flow testing.
Condition testing test the logical conditions contained in a procedural specification.
Looping testing is a method that focuses exclusively on the validity of iterative constructs or repetition.
Data Flow Testing method selects test paths of a program according to the locations of the definitions and uses of variables in the program.