You can perform different kinds of testing in software engineering, such as black box testing, white box testing, and grey box testing. In this article, I will talk about the grey box testing in detail. Grey box testing provides the ability to test both the presentation layer as well as the coding layer of an application. With grey box techniques, you know a little bit about the target, pretty much from the perspective of the user. So, you have user level access to the target. This kind of testing is majorly used in penetration testing, domain testing, and integration testing. Grey box testing is sometimes also referred to as translucent testing, and it is majorly used for web-based applications.
What is Grey Box Testing?
Grey box is the combination of both White Box and Black Box Testing. ‘Grey’ box testing is sometimes also spelled as ‘Gray’ box. The tester who works on grey box testing needs to have access to all the design documents. This helps to create better test cases in this process. This testing technique is used to test a software product or application with partial knowledge of the internal structure of the application. The purpose of grey box testing is to search and identify the defects due to improper or improper use of applications. It is a strategy for software debugging in which testers have limited knowledge of internal details of the program and partial understanding of algorithms for defining the test cases.
The strategy of grey box testing is based on the knowledge of architecture, algorithms, internal states, and high-level description of behavior of the program. An example of grey box testing can you check the links on a website. If a tester finds out that a particular link in the website is not working, then the tester can change the link in the HTML code of the website and then recheck it in real-time.
Below are the objectives of grey box testing:
- To improve the overall quality of the software or product or application
- To provide extra time to developers to fix the issues in the software
- To combine the inputs of testers and developers
- To provide advantages of both white box testing and black box testing
- To reduce the overhead of functional and non-functional testing which have long processes
- To test the software not from the designer point of view but from the user point of view
Grey Box Testing Techniques
Below are the testing techniques used in the Grey box:
Regression Testing
- We use regression testing to verify the code change has not adversely affected existing features.
- Regression testing is performed on the software after every change in the software to make sure that any change or the new functionalities of the software are not affecting the existing functioning of the system.
- Regression testing is also done to ensure that fixing any defect of the software has not affected other functionality of the software.
Pattern Testing
- In pattern testing technique, you perform the testing to analyze the previous defects.
- Pattern testing determines the reason for the failure by looking into the application’s code.
- The analysis template contains the reasons for the defect in the application.
- This helps test cases designed as they are proactive in finding their failures before hitting production.
Orthogonal Array Testing
- Orthogonal array testing is mainly a black box testing technique.
- On orthogonal array testing, test data have n numbers of permutations and combinations.
- Orthogonal array testing is preferred, and maximum coverage is required when there are very few test cases and test data is huge.
- This testing technique is very helpful in testing complex applications.
Matrix Testing
- In the matrix testing technique, technical and business risks identified by the developers in software programs are examined.
- Developers define every variable that exists in the program.
- All the variables have an inherent business and technical risk and can be used with a varied frequency during its life cycle.
Benefits of Grey Box Testing
Below are some important benefits of grey box testing:
- It provides clear goals to users and developers while performing the testing
- It provides better quality products
- It checks the product from user’s perspective
- It doesn’t require excellent programming skills to perform the testing on the product
- It provides enough time for developers to fix the identified issues
- It gives an unbiased result of the testing and removes the conflict between a developer and a tester
- It is more effective when integration testing is performed
- It provides the benefits of both white box testing and black box testing
Drawbacks of Grey Box Testing
Below are some drawbacks of using grey box testing:
- The test cases are not very straightforward to design, they are complex
- Grey box testing is not suitable for algorithm testing
- This type of testing is not suited for distributed systems as it is complex to find defect association
- It has limited access to the internal structure code and hence limited code path traversal
- You cannot access the source in grey box testing, and that is why it cannot perform white box testing completely
- Some of the tests can become redundant, if the developer has already done similar tests
Final Thoughts
So that was all the fundamentals you needed to know about grey box testing. It is a very beneficial testing type that combines the testing techniques of both black box testing and white box testing. The fundamental difference between black box, white box and grey box is that in black box testing, the code structure is not known, in white box testing the internal code structure is known, and in grey box testing the internal code structure is partially known. Compared to other testing types, grey box testing can be used in complex scenarios, and it is capable of testing applications in a better way.
