In many software testing situations, white box testing, where the internal code of what is being tested is visible to the tester, and black box testing, where the internal code of what is being tested isn’t visible to the tester, are some of the most often used methods. However, integrating elements from both methods into a single testing method is slowly seeing more widespread use, also known as Gray box testing. In the blog “Exploring gray box testing techniques” by Dominik Szahidewicz, the author details different examples of gray box testing, and the benefits of those examples compared to the use of only white or black box testing.
Gray box testing has noticeable benefits that are absent from both white and black box testing. By the using the principles of white box testing (internal structure and design) and of black box testing (output without the context of internal structure), the testing process can be robust and able to account for any problem case.
A specific testing example where gray box testing can be implemented is pattern testing, where recurring patterns are leveraged to improve programs. With the use of gray box testing, the internal structure of the software can be related with the output to create more helpful and efficient test cases.
Another testing example where gray box testing can be implemented is orthogonal array testing, where data for testing is organized into specific test cases. This method is commonly used where exhaustive testing using every possible input is unreasonable because of the amount of inputs. By using the internal structure of the program and the outputs of the program, more efficient test cases can be created.
A basic guide as to how to implement gray box testing includes 4 steps detailed by the author. The first step of of the implementation is acquiring system knowledge. This includes documenting the internals available for use in testing, as well as the available documentation of outputs from the tested program. The second step is to define test cases according to known information and specifications. The third step is the use of both functional and non functional testing. The fourth step is to analyze the results of testing.
From the blog CS@Worcester – My first blog by Michael and used with permission of the author. All other rights reserved by the author.



