(Bilgisayar) White-box testing (also called glass-box or clear box testing) is the test in which a tester knows the internal program structure and its code. As a result, the tester can execute each program statement and function; check each intended error handling, etc. This testing involves source code reviews, walkthroughs, as well as design and execution of tests based on the access to the program code. White-box testing requires deeper knowledge of programming languages and technologies than black-box testing