<dependencies>
<!-- JUnit -->
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.13.2</version>
<scope>test</scope>
</dependency>
</dependencies>
public interface Calculator {
int sum(int a, int b);
}
public class SimpleCalculator implements Calculator {
public int sum(int a, int b) {
return a + b;
}
}
import org.junit.Test;
import static org.junit.Assert.assertEquals;
public class CalculatorTest {
private Calculator calculator = new SimpleCalculator();
@Test
public void testSum() {
int result = calculator.sum(2, 3);
assertEquals(5, result);
}
@Test
public void testZeroSum() {
int result = calculator.sum(0, 0);
assertEquals(0, result);
}
@Test
public void testNegativeSum() {
int result = calculator.sum(-2, -3);
assertEquals(-5, result);
}
}
