Testing getters and setters with openpojo

Testing getters and setters is a little bit controversial topic. However, if we decide to do it or if we are forced to, we can ease the task with openpojo library.

Generally standard getters and setters can be generated by your IDE but testing them is a manual work - it takes some time and seems to be boring. So if the code was generated, why can't we automate the testing?
openpojo doesn't generate the unit test but it allows to test your POJO with a very small effort.

Let's take a look at an example. We have a Person class which is a POJO with generated getters and setters.

	package pl.mjedynak.openpojo;
	public class Person {
	private String name;
	private int age;
	public String getName() {
	return name;
	}
	public void setName(String name) {
	this.name = name;
	}
	public int getAge() {
	return age;
	}
	public void setAge(int age) {
	this.age = age;
	}
	@Override
	public boolean equals(Object o) {
	if (this == o) return true;
	if (!(o instanceof Person)) return false;
	Person person = (Person) o;
	if (age != person.age) return false;
	if (name != null ? !name.equals(person.name) : person.name != null) return false;
	return true;
	}
	@Override
	public int hashCode() {
	int result = name != null ? name.hashCode() : 0;
	result = 31 * result + age;
	return result;
	}
	}

view raw Person.java hosted with ❤ by GitHub

To test it we need to create just one class:

	public class PojoTest {
	private static final String POJO_PACKAGE = "pl.mjedynak.openpojo";
	private List<PojoClass> pojoClasses;
	private PojoValidator pojoValidator;
	@Before
	public void setup() {
	pojoClasses = PojoClassFactory.getPojoClasses(POJO_PACKAGE, new FilterPackageInfo());
	pojoValidator = new PojoValidator();
	pojoValidator.addRule(new GetterMustExistRule());
	pojoValidator.addRule(new SetterMustExistRule());
	pojoValidator.addTester(new SetterTester());
	pojoValidator.addTester(new GetterTester());
	}
	@Test
	public void testPojoStructureAndBehavior() {
	for (PojoClass pojoClass : pojoClasses) {
	pojoValidator.runValidation(pojoClass);
	}
	}
	}

view raw PojoTest.java hosted with ❤ by GitHub

Our class defines which rules openpojo will apply and what tests it will execute. We also specify which package will be tested - if we have a lot of classes we can test them all in one go. In our case we're only testing if  getters and setters exist and if they behaving in a conventional way.
Running the class with any coverage tool will show us that the get and set methods are executed.
There are more rules that we can apply (like checking if there are no public fields, no primitive values etc.). We can write our own rules as well.