White-box testing (also known as clear box testing, glass box testing, transparent box testing, and structural testing) is a method of software testing that tests internal structures or workings of an application, as opposed to its functionality (i.e. black-box testing). In white-box testing, an internal perspective of the system is used to design test cases. The tester chooses inputs to exercise paths through the code and determine the expected outputs. This is analogous to testing nodes in a circuit, e.g. in-circuit testing (ICT). White-box testing can be applied at the unit, integration and system levels of the software testing process. Although traditional testers tended to think of white-box testing as being done at the unit level, it is used for integration and system testing more frequently today. It can test paths within a unit, paths between units during integration, and between subsystems during a system–level test. Though this method of test design can uncover many errors or problems, it has the potential to miss unimplemented parts of the specification or missing requirements. Where white-box testing is design-driven,[1] that is, driven exclusively by agreed specifications of how each component of software is required to behave (as in DO-178C and ISO 26262 processes), white-box test techniques can accomplish assessment for unimplemented or missing requirements.

Quick facts: Black box systems, System, Methods and techni...
Black box systems
Black box · Oracle machine
Methods and techniques
Black-box testing · Blackboxing
Related techniques
Feed forward · Obfuscation · Pattern recognition · White box · White-box testing · Gray box testing · System identification
A priori information · Control systems · Open systems · Operations research · Thermodynamic systems

White-box test design techniques include the following code coverage criteria: