JUnit is an open-source unit testing framework for the Java programming language. It is designed to assist software developers in writing and running repeatable tests to ensure the correctness of individual units of code, such as methods, classes, or interfaces. JUnit follows the principles of test-driven development, promoting the concept of writing tests before writing the code that needs to be tested.
JUnit provides a set of annotations and assertions that allow developers to define test cases and assert expected results. Test cases are written as methods and are annotated with the @Test annotation to indicate that they are test methods. Assertions are used within these methods to verify expected outcomes. JUnit also supports other annotations, including @Before and @After, which are used to define setup and teardown methods that are invoked before and after each test method execution.
The framework provides a test runner, which is responsible for executing test cases and reporting the results. It generates a detailed report indicating which tests passed, which failed, and any exceptions or errors encountered during execution.
JUnit can be easily integrated with various development tools and build systems, such as Eclipse, IntelliJ, Maven, and Ant, making it widely adopted in the Java community. Its simplicity and extensibility have made it one of the most popular unit testing frameworks for Java developers.
