@Test void testSubtract() { assertEquals(5, calculator.subtract(10, 5), "Subtraction failed"); }
public static void main(String[] args) { Calculator calculator = new Calculator(); System.out.println("Addition: " + calculator.add(10, 5)); System.out.println("Subtraction: " + calculator.subtract(10, 5)); System.out.println("Multiplication: " + calculator.multiply(10, 5)); System.out.println("Division: " + calculator.divide(10, 5)); } } 4.1 Write Unit Tests Create a test class CalculatorTest.java in src/test/java/com/example :
public double subtract(double a, double b) { return a - b; }
@Test void testDivide() { assertEquals(2, calculator.divide(10, 5), "Division failed"); } maven minx work
calculator/ ├── pom.xml └── src ├── main │ └── java │ └── com │ └── example │ └── App.java └── test └── java └── com └── example └── AppTest.java Let's add a feature to our calculator application that allows it to perform addition, subtraction, multiplication, and division. 3.1 Create a Calculator Class Create a new Java class Calculator.java in src/main/java/com/example :
public double multiply(double a, double b) { return a * b; }
import org.junit.jupiter.api.Test; import static org.junit.jupiter.api.Assertions.assertEquals; import static org.junit.jupiter.api.Assertions.assertThrows; @Test void testSubtract() { assertEquals(5, calculator
package com.example;
// src/main/java/com/example/App.java
private Calculator calculator = new Calculator(); @Test void testSubtract() { assertEquals(5
// src/test/java/com/example/CalculatorTest.java
package com.example;
@Test void testAdd() { assertEquals(15, calculator.add(10, 5), "Addition failed"); }