Detailed analysis of the technical principles of Junit Jupiter Engine framework in Java

The Junit Jupiter Engine framework is one of the most popular test frameworks in the Java class library, which is widely used in the Java unit testing and integrated test.This article will analyze the technical principles of the Junit Jupiter Engine framework and provide some Java code examples. Introduction to Junit Jupiter Engine framework Junit Jupiter Engine is part of Junit 5, which is developed to support Junit 5 and provide a scalable test engine.Junit Jupiter Engine provides a series of APIs and annotations for writing and executing test code. Junit Jupiter Engine's design goal is to provide more powerful, scalable test frameworks, enabling developers to write test code more flexibly.It provides many new features, such as supporting LAMBDA expression, custom test annotations, parameterized testing, dynamic testing, etc. Second, Junit Jupiter Engine framework technical analysis analysis 1. Comment drive JUNIT JUPITER Engine uses annotation drive to manage the test code.Developers can use @test annotations to represent a test method, using @BefaceEach and @AfaceReach annotations to indicate the method that needs to be executed before and after each test method is executed.Junit Jupiter Engine also provides some other annotations, such as @BefaceAll and @Afacerall, which means to indicate methods that need to be executed before and after all test methods. 2. Extension model Junit Jupiter Engine provides a scalable model that enables developers to customize test engines and test expansion.By achieving custom test engines, developers can add new functions and characteristics to the test framework.Junit Jupiter Engine also provides a lot of extension points, such as custom test execution monitoring, custom parameter parser, custom test conditions, etc. 3. Test execution process Junit Jupiter Engine's test execution process includes test discovery, test planning, test execution, and test reports.During the test discovery stage, Junit Jupiter Engine scan the test class and find all the test methods.During the test plan, Junit jobr Engine creates an execution plan based on the dependency relationship of the test method.During the test execution phase, Junit jobr Engine will perform the test method in accordance with the execution plan.During the test report phase, Junit jobr Engine will generate test reports and output test results. Junit Jupiter Engine code example Below is a simple example of using Junit Jupiter Engine: import org.junit.jupiter.api.Assertions; import org.junit.jupiter.api.Test; public class ExampleTest { @Test public void testSum() { int result = sum(2, 3); Assertions.assertEquals(5, result); } private int sum(int a, int b) { return a + b; } } In the above example, we use the @teest annotation to indicate that the testsum method is a test method.Assereles.asserTequals method is used to determine whether the return value of the method is the same as the expected result. Through the above code example, we can see a part of the technical principle of Junit Jupiter Engine framework.It realizes a powerful and flexible test framework through the characteristics of annotations, extension models, and test execution processes.Developers can use Junit Jupiter Engine to write and execute test code according to their needs.