Unit testing focuses on testing individual units of code, such as functions or methods, in isolation from the rest of the application.

PyUnit is a popular unit testing framework for Python that provides a simple and flexible way to write and run unit tests.

Exception testing involves testing a function or method to ensure that it raises the appropriate exception when it is called with invalid input.

Positive testing involves testing a function or method to ensure that it returns the expected output when it is called with valid input.

JUnit is a popular unit testing framework for Java that provides a simple and flexible way to write and run unit tests.

Robustness testing involves testing a function or method to ensure that it returns the expected output when it is called with a variety of different inputs.

Stress testing involves testing a function or method to ensure that it performs as expected under a heavy load.

MSTest is a popular unit testing framework for C# that provides a simple and flexible way to write and run unit tests.

Endurance testing involves testing a function or method to ensure that it performs as expected over a long period of time.

Concurrency testing involves testing a function or method to ensure that it performs as expected when it is called concurrently by multiple threads.

Distributed testing involves testing a function or method to ensure that it performs as expected when it is called in a distributed system.

Cloud testing involves testing a function or method to ensure that it performs as expected when it is called in a cloud environment.

Mobile testing involves testing a function or method to ensure that it performs as expected when it is called in a mobile environment.

Embedded testing involves testing a function or method to ensure that it performs as expected when it is called in an embedded system.

Safety testing involves testing a function or method to ensure that it performs as expected when it is called in a safety-critical system.