Testing with JUnit 5

Test classes are not part of the usual source code folder, src/main/java. Instead, they are placed in src/test/java. They can and should be organized into packages. You can also have resources that are just used by the test classes, such as logging.properties or log4j2.xml. They will be placed in src/test/resources.

We will need to add new components to our Maven pom.xml file. The first is the dependency for JUnit 5. The first addition is the bill of materials (BOM), in a section called dependencyManagement:

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.junit</groupId>
                <artifactId...