Interview Questions

white box testing

Glossary of Software QA/Testing

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white box testing

1.White box testing is based on knowledge of the internal logic of an application's code. Tests are based on coverage of code statements, branches, paths and conditions.

Clear box testing is white box testing. Glass box testing is also white box testing. Open box testing is also white box testing.
2. White box testing is a testing approach that examines the application's program structure, and derives test cases from the application's program logic.

3. Testing approaches that examine the program structure and derive test data from the program logic. This is also known as clear box testing, glass-box or open-box testing. White box testing determines if program-code structure and logic is faulty. The test is accurate only if the tester knows what the program is supposed to do. He or she can then see if the program diverges from its intended goal. White box testing does not account for errors caused by omission, and all visible code must also be readable.

4. White box method relies on intimate knowledge of the code and a procedural design to derive the test cases. It is most widely utilized in unit testing to determine all possible paths within a module, to execute all loops and to test all logical expressions.
Using white-box testing, the software engineer can (1) guarantee that all independent paths within a module have been exercised at least once; (2) examine all logical decisions on their true and false sides; (3) execute all loops and test their operation at their limits; and (4) exercise internal data structures to assure their validity (Pressman, 1997). This form of testing concentrates on the procedural detail. However, there is no automated tool or testing system for this testing method. Therefore even for relatively small systems, exhaustive white-box testing is impossible because of all the possible path permutations.

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