Gray Box Testing in Software Testing

Introduction to Gray Box Testing

Gray box testing signifies tester can partially see the code hence, the test cases are centric functionality where the basics of coding are required. In white-box testing, the entire focus is on the internal structure of the code whereas, in black-box testing, only functionality is tested. In Gray box testing code knowledge is also required to ensure the output is correct. For example- SQL injection test cases are written which require knowledge of SQL.

Objectives of Gray Box Testing

1. To improve the quality of the product.
2. To find the missing pointers by the developer.
3. To take input from the tester.
4. To test the product from the user's point of view.

Gray Box Testing Techniques

1. Matrix Testing: In matrix testing, a grid is prepared where functionalities and business requirements are listed. On the other hand test cases subjective to the variable components are written. For example in the login module-username, password forgot password, change password, email verification all these functionalities are tested.
2. Pattern Testing: In testing there is a well-known fact that 90% of defects are in 10% of modules. In pattern testing, those modules are identified first. It makes finding the defect easier under defect clustering law. Test cases are designed based on the defect ratio pattern based on previous defect templates.
3. Orthogonal Array Testing: Orthogonal array testing is primarily a black box testing technique where different permutations and combinations are obtained to club the variable components otherwise test data would become huge. OAT helps to maximize test coverage with minimum unique test cases.
4. Regression Testing: Regression testing ensures new code changes do not affect the previous functionalities. Regression testing also tests that the new bug fix has not affected the existing code. Regression testing is an integration testing technique where after new changes have been tested, their integration with previous modules is tested again.

Steps to Perform Gray box Testing

• Step 1: Identify the functionality under test

• Step 2: Identify the input parameters

• Step 3: Identify the path structure via looking at the code structure

• Step 4: Execute the test cases

• Step 5: Verify the output obtained

Gray Box Testing Challenges

1. Since gray box testing requires basic code knowledge, writing quality test cases that test various parameters of testing is a challenge.
2. Gray box testing requires experienced testers as they can find loopholes in the code to validate the output.
3. Gray box testing does not improve the quality of the code but rather validates only the functionality of the application.

Advantages/Disadvantages of Gray Box Testing

Advantages of Gray Box Testing

1. Gray box testing is best used for integration testing as here data flow knowledge is mandatory.
2. Gray box testing tester is pushed to write test cases that which developer might have missed.
3. Gray box testing gives the developer more time to fix the errors.
4. Gray box testing does focus on the logical part of the code than the structure of the code.

Disadvantages of Gray Box Testing

1. Gray box testing requires deep knowledge of the data flow throughout the application.
2. Gray box testing does not improve the code quality but only product quality.
3. Gray box testing is challenging for the tester.
4. Gray box testing is not used for algorithmic testing.