Interpretation of the technical principles of the Junit Jupiter Engine framework in the Java class library

Junit Jupiter Engine is a framework in the Java class library to help developers write and perform unit testing.It is part of Junit 5, providing developers with more functions and flexibility.The technical principles of the Junit Jupiter Engine framework are as follows: 1. Note Driven Test: Junit Jupiter Engine uses annotations to define test cases and test operators to drive the test process.Developers can use @Test annotations to mark the test method and use other annotations to configure the test environment. The following is a simple example: import org.junit.jupiter.api.Test; public class MyTestClass { @Test public void myTest() { // Test code } } 2. Extension model: Junit JumpIR Engine provides more flexibility by extending models.It introduces a series of new interfaces and annotations that enable developers to customize the behavior and execution process of testing methods.For example,@beforeeach and @AfaceReach annotations can be used to define operations that need to be performed before and after each test method. The following is an example: import org.junit.jupiter.api.*; public class MyTestClass { @BeforeEach public void setUp() { // The code executed before each test method is executed } @AfterEach public void tearDown() { // The code executed after each test method is executed } @Test public void myTest() { // Test code } } 3. Adventure support: Junit Jupiter Engine provides a wealth of assertions to verify whether the test results meet the expectations.Developers can use these assertions to write more expressive and readable test code. The following is an example: import org.junit.jupiter.api.Test; import static org.junit.jupiter.api.Assertions.assertEquals; public class MyTestClass { @Test public void myTest() { String actual = "Hello, world!"; assertEquals("Hello, world!", actual); } } 4. Extensibility: Junit Jupiter Engine has good scalability, allowing developers to write custom extensions to meet specific needs.Developers can add custom functions and behaviors by achieving extended interfaces. The above is the technical principle of the Junit Jupiter Engine framework.Through annotations such as testing, extension models, assertions, support and scalability, Junit Jupiter Engine provides developers with a powerful and flexible way to write and perform unit testing.