JUnit

JUnit is a widely used testing framework for Java applications. It provides a simple and efficient way to write and run repeatable tests, making it an essential tool for developers practicing Test-Driven Development (TDD) and ensuring code quality. Here’s an overview of JUnit, its features, and how it is used in testing:

Key Features of JUnit

1. Annotations: JUnit uses annotations to define test methods and configure test execution. Common annotations include:

• @Test: Marks a method as a test method.
• @Before: Executed before each test method; used for setup.
• @After: Executed after each test method; used for cleanup.
• @BeforeClass: Executed once before any test methods in the class; used for class-level setup.
• @AfterClass: Executed once after all test methods in the class; used for class-level cleanup.
• @Ignore: Marks a test method to be ignored during execution.

1. Assertions: JUnit provides a set of assertion methods to validate expected outcomes. Common assertions include:

• assertEquals(expected, actual): Checks if two values are equal.
• assertTrue(condition): Checks if a condition is true.
• assertFalse(condition): Checks if a condition is false.
• assertNull(object): Checks if an object is null.
• assertNotNull(object): Checks if an object is not null.

1. Test Suites: JUnit allows grouping multiple test classes into a test suite, enabling the execution of all tests in a single run.
2. Parameterized Tests: JUnit supports parameterized tests, allowing the same test to be run multiple times with different inputs.