@TestForIssue(jiraKey = "HV-975")
public class OptionalTest {

	@Test
	public void testPrivateGetter() {
		Validator validator = getValidator();

		Set<ConstraintViolation<Project>> constraintViolations = validator.validate(
				new Project( LocalDate.MIN, LocalDate.MAX )
		);
		assertNumberOfViolations( constraintViolations, 0 );
	}

	@Test
	public void testPrivateGetterII() {
		Validator validator = getValidator();

		Set<ConstraintViolation<Project>> constraintViolations = validator.validate(
				new Project( LocalDate.MAX, LocalDate.MIN )
		);
		assertNumberOfViolations( constraintViolations, 1 );
		assertCorrectConstraintTypes( constraintViolations, AssertTrue.class );
		assertCorrectPropertyPaths( constraintViolations, "startBeforeEnd" );
	}

	@Test
	public void testPrivateGetterIII() {
		Validator validator = getValidator();

		Set<ConstraintViolation<Project>> constraintViolations = validator.validate(
				new Project( LocalDate.now(), null )
		);
		assertNumberOfViolations( constraintViolations, 2 );
		assertCorrectConstraintTypes( constraintViolations, AssertTrue.class, NotNull.class );
		assertCorrectPropertyPaths( constraintViolations, "end", "startBeforeEnd" );
	}

	@Test
	public void testPrivateGetterIV() {
		Validator validator = getValidator();

		Set<ConstraintViolation<Project>> constraintViolations = validator.validate(
				new Project( null, null )
		);
		assertNumberOfViolations( constraintViolations, 3 );
		assertCorrectConstraintTypes( constraintViolations, AssertTrue.class, NotNull.class, NotNull.class );
		assertCorrectPropertyPaths( constraintViolations, "start", "end", "startBeforeEnd" );
	}
}

public class Project {
	private final LocalDate start;
	private final LocalDate end;

	public Project(LocalDate start, LocalDate end) {
		this.start = start;
		this.end = end;
	}

	@NotNull
	@UnwrapValidatedValue
	public Optional<LocalDate> getStart() {
		return Optional.ofNullable( this.start );
	}

	@NotNull
	@UnwrapValidatedValue
	public Optional<LocalDate> getEnd() {
		return Optional.ofNullable( this.end );
	}

	// Throws NullPointerException:
	@AssertTrue
	private Boolean getStartBeforeEnd() {
		return this.getStart().orElse( LocalDate.MAX ).isBefore( this.getEnd().orElse( LocalDate.MIN ) );
	}
}