I am writing in response to the blog post at https://www.guru99.com/grey-box-testing.html titled “Grey Box Testing: Process, Techniques, Strategy, Challenges”.
Grey box testing, as the name suggests, is meant to be a combination of black box testing and white box testing. In white box testing, the internal structure of the code is known, and in black box testing, the structure of the code is unknown, and in grey box testing, it is partially known. Grey box testing combines the benefits of black box testing and white box testing, combining the input of developers while testing from the perspective of a user.
An example of grey box testing is given where a tester is testing a website and something is wrong with the HTML code, so the tester is able to look at and make changes to the code themselves to continue testing. A few other types of testing are listed as qualifying as being in the category of grey box testing: matrix testing, regression testing, orthogonal array testing, and pattern testing. These methods follow the strategy of black box testing while integrating some white box testing practices to focus more on what the test cases should be looking for.
A sequence of steps is provided for how to perform grey box testing. The first two steps, identifying inputs and outputs, do not seem to be directly related to black box testing or white box testing alone. In black box testing, there would be no need to explicitly identify the inputs and outputs; they would already be given in the test specification. The creation of the specification does require access to the code, which relates to white box testing, so grey box testing in this sense seems like a real-time testing approach where there is not necessarily a pre-developed specification and learning about the environment is a part of the testing process.
Challenges in grey box testing that are listed include when a test executes and the result is incorrect, and when something being tested encounters some failure. These do not really sound like challenges, they seem to just be examples of what testing is for.
From the blog cs-wsu – klapointe blog by klapointe2 and used with permission of the author. All other rights reserved by the author.