The technical principles and application practice of the Junit Jupiter (polymer) framework
The technical principles and application practice of the Junit Jupiter (polymer) framework
Junit is a widely used open source unit test framework, which is known for its simple and ease of use and flexibility.However, the Junit framework itself has experienced continuous evolution and improvement, and one of the important development is Junit Jupiter (also known as Junit 5).Junit Jupiter is a new test engine introduced by Junit 5, which provides a new set of annotations and extensions to improve the readability and maintenance of the test.This article will explore the technical principles of the Junit Jupiter framework and how to use it in practical applications.
Technical principle:
The core concept of Junit Jupiter is to indicate the ordinary Java method that expresses test cases as an annotation decoration.These annotations include:
-@Test: Used to mark a test method.
-@Beforeeach: Used to execute the method before each test method.
-@AFTEREACH: The method for executing after each test method is performed.
-@Befaceall: The method for executing before all test methods.
-@AFTERALL: The method for executing after all test methods.
Junit Jupiter also introduced Assert and Assertion Methods to verify whether the desired results and actual results match.Commonly used assertions are Assertequals (), Asserttrue (), and AssertFalse ().
Application practice:
Below is an example of using the Junit Jupiter framework to test a simple calculator class:
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;
public class CalculatorTest {
private Calculator calculator;
@BeforeEach
public void setUp() {
calculator = new Calculator();
}
@Test
public void testAdd() {
int result = calculator.add(2, 3);
assertEquals(5, result);
}
@Test
public void testSubtract() {
int result = calculator.subtract(5, 3);
assertEquals(2, result);
}
@Test
public void testMultiply() {
int result = calculator.multiply(2, 3);
assertEquals(6, result);
}
@Test
public void testDivide() {
double result = calculator.divide(10, 2);
assertEquals(5.0, result);
}
}
In the above example, the test method is marked with the Junit Jupiter's annotation to marked each test method as @test, and the various operations of the calculator class are used to verify the calculation method.
In addition to basic annotations and assertions, Junit Jupiter also supports high -level functions such as parameterized testing and dynamic testing. These functions make the test more flexible and powerful.
Summarize:
The Junit Jupiter framework provides a simple and powerful way to perform unit testing by annotations and assertions.Its technical principle is based on the ordinary Java method that expresses the test case as the reason to annotate the decoration, and uses an assertion method to verify the results.In practical applications, we can use the Junit Jupiter framework to quickly write and perform unit testing to ensure the quality and reliability of the code.
