Unit testing

Writing your first test

We use @Test and JUnit assertions to organize our tests:

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.*;

public class SmartLightTest {

    @Test
    public void testSmartLightShouldBeOffByDefault() {
        SmartLight device = new SmartLight("warm white", 75);
        assertFalse(device.isOn());
    }
}

• @Test: This annotation marks a method as a test method.

• assertFalse: This is a JUnit assertion that checks if the condition is false, which is equivalent to checking that the smart light is off by default.

• JUnit Assertions: JUnit has a wide range of assertions like assertEquals(), assertTrue(), assertNull(), etc.

Running your tests

In Maven projects, to run your tests, use the following configuration in the pom.xml:

<build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-surefire-plugin</artifactId>
            <version>3.0.0-M5</version> <!-- Ensure you have the correct version -->
            <configuration>
                <includes>
                    <include>**/*Test.java</include> <!-- Includes all test files -->
                </includes>
            </configuration>
        </plugin>
    </plugins>
</build>

Then, execute the following command in your terminal to run your tests:

mvn test

Exploring more features

JUnit has many powerful features such as test suites, parameterized tests, and more. When you have the opportunity, you should explore the JUnit documentation to learn more about what it can do.