What are the differences between unit testing and white box testing?

Unit testing and white box testing are both software testing methodologies, but they focus on different aspects of the testing process. Here are the key differences between unit testing and white box testing:

Unit Testing:

1. Scope:

   • Unit testing is a type of testing where individual components or functions of a software application are tested in isolation.
   • It focuses on verifying that each unit of the software performs as designed.

2. Purpose:

   • The main goal of unit testing is to validate that each unit of the software performs its functions correctly as per the design specifications.

3. Isolation:

   • Unit testing is usually performed in isolation, meaning that the code being tested is separated from the rest of the application.

4. Test Cases:

   • Test cases in unit testing are often written by developers and are designed to test specific functionalities or methods within the code.

5. Knowledge:

   • Unit testing is typically carried out without detailed knowledge of the internal workings of the system. Testers focus on inputs and expected outputs.

White Box Testing:

1. Scope:

   • White box testing is a testing technique that examines the internal logic and structure of the code.
   • It tests how well the internal components of a system work together.

2. Purpose:

   • The primary goal of white box testing is to ensure that all paths of the code are executed at least once and that all logical conditions are verified.

3. Isolation:

   • White box testing requires knowledge of the internal workings of the application, and it may involve testing the interaction between different components.

4. Test Cases:

   • Test cases in white box testing are designed based on the internal logic of the code, and they aim to achieve code coverage, ensuring that every line of code is executed.

5. Knowledge:

   • White box testing requires a good understanding of the internal structure and implementation of the software. Testers need to have knowledge of the code, algorithms, and data structures.

In summary, unit testing focuses on testing individual units or components of the software in isolation, often with a developer's perspective, while white box testing examines the internal logic and structure of the code, requiring a deeper understanding of the application's internals.