Analysis of the technical principles of the Junit Jupiter Engine framework in the Java class library
Junit Jupiter Engine is one of the core components in the Junit 5 test framework, which is responsible for executing and managing test cases.In this article, we will explore the technical principles of Junit Jupiter Engine and help readers better understand by providing Java code examples.
Introduction to Junit Jupiter Engine
Junit Jupiter Engine is a module of the Junit 5 test framework. It is the execution engine of Junit 5, which is responsible for the execution of the driving test case.The core principle of Junit Jupiter Engine is to allow developers to create and perform multiple types of testing, such as traditional unit testing, parameterized testing and dynamic testing.Junit Jupiter Engine uses a modular design to decouple the specific implementation of the test case and the test framework to provide a more flexible test framework.
2. Junit Jupiter Engine technical analysis analysis
1. Note driver test: Junit Jupiter Engine provides a variety of annotations, such as `@test`,@beForeEach`,` `@afterreach`, etc., developers can use these annotations to mark the execution logic of test cases, thereby running through operation.The reflex mechanism is automatically found and executed for test cases.
The following is an example code using Junit Jupiter Engine:
import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.assertEquals;
public class MyTest {
@Test
void testSum() {
int result = 2 + 2;
assertEquals(4, result);
}
}
In this example, the `@test` annotation marked the method of` testsum () `as a test case, using an assertion to verify the calculation results during the test process.
2. Extended model: Junit JumpIR Engine provides an extension model, which developers can customize extensions to achieve specific test logic.By implementing the `TESTTEMPLEINVOCONTExtProvider` interface, the parameterization test logic can be customized. By implementing the` dynamicTestexecutor` interface, dynamic test logic can be achieved.This expansion model can meet various test needs, and improve the flexibility and scalability of testing.
The following is an example code of an extended model:
import org.junit.jupiter.api.DynamicTest;
import org.junit.jupiter.api.TestFactory;
import org.junit.jupiter.api.function.Executable;
import java.util.Arrays;
import java.util.List;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.DynamicTest.dynamicTest;
public class MyTest {
@TestFactory
List<DynamicTest> testFactory() {
List<String> numbers = Arrays.asList("1", "2", "3");
return numbers.stream()
.map(number -> dynamicTest("Test " + number, () -> {
int parsedNumber = Integer.parseInt(number);
assertEquals(parsedNumber, parsedNumber);
}))
.toList();
}
}
In this example, the annotation of `@testFactory` is used to mark` testFactory () `method as a test factory, which dynamically creates a set of test cases, each test case is processed and executed during runtime.
3. Extended interface and listener: Junit Jupiter Engine provides multiple extension interfaces and listeners. Developers can implement these interfaces and listeners from defining test logic and listening test life cycle events.For example, you can achieve the beginning, end, success or failure of the test test to monitor the test of the test.
The following is an example code for a custom monitor:
import org.junit.jupiter.api.extension.ExtensionContext;
import org.junit.jupiter.api.extension.TestExecutionExceptionHandler;
import org.junit.jupiter.api.extension.TestExtensionContext;
public class MyTestExecutionExceptionHandler implements TestExecutionExceptionHandler {
@Override
public void handleTestExecutionException(TestExtensionContext context, Throwable throwable) throws Throwable {
System.err.println("Test failed: " + context.getDisplayName());
throw throwable;
}
}
In this example, `MyTETETEXECUTIONEXCEPTIONHANDLER` implements the` TestexecutionExceptionHandler` interface. When the test execution is abnormal, it captures and output error information.
3. Conclusion
Junit Jupiter Engine is one of the core components in the Junit 5 test framework, responsible for execution and management test cases.This article analyzes the technical principles of Junit Jupiter Engine and provides examples of Java code to help readers better understand the working principles and usage methods of Junit Jupiter Engine.Through in -depth learning Junit Jupiter Engine, developers can better write high -efficiency, flexible and scalable test cases.
