Introduction

The validation-violation-checker is a little tool to check Contraint Violations (result of JSR303 Bean Validation) against expectation in JUnit test.

Some may say these JUnit tests are integration tests to test the validation implementations. But in the daily business it is very handsome to be quickly able to test if the validation annotations are set correctly.

Prerequisites

The validation-violation-checker needs to run

• Java 1.7 or newer
• JUnit 4 or newer
• javax.validation.validation-api 1.1.0 or higher
• Apache commons lang3

Using validation-violation-checker

Maven dependency

In case you use Maven just add the dependencies

	<dependency>
		<groupId>de.flexguse.util.junit</groupId>
		<artifactId>validation-violation-checker</artifactId>
		<version>0.2</version>
		<scope>test</scope>
	</dependency>

to your Maven dependencies. All required dependencies are added automatically to your project.

ValidationViolationChecker

Using the validation-violation-checker is quite easy. There is a static method for checking ConstraintViolationExceptions and a public checking method for checking a set of ConstraintViolations.

Using the static method

Do something like method validation and catch the exception, i.e.

		try{
			userService.saveUser(user);
		}catch(ConstraintViolationException e){
				ValidationViolationChecker.checkExpectedValidationViolations(e,
					Arrays.asList(UserErrorMessages.NO_EMAIL,
							UserErrorMessages.NO_LOGIN,
							UserErrorMessages.NO_PASSWORD));
		}

Using public method

Create an instance of ValidationViolationChecker, i.e.

		private ValidationViolationChecker<User> checker = new ValidationViolationChecker<>();

Do your Java JSR303 BeanValdation, i.e.

		Set<ConstraintViolation<RemoteSite>> violations = validator
				.validate(RemoteSite.builder().build());

and check if the violations contain the validation errors you expected

		checker.checkExpectedValidationViolations(violations, Arrays
				.asList("error 1", "error 2", "error 3"));

The ValidationViolationChecker uses internally the Junit Assert methods, so calling the method 'checkExpectedValidationViolations' produces a meaningful Junit assertion error.

i18n and ValidationViolationChecker

If you use resource bundles to make your validation errors multilanguage this is absolutely no problem for ValidationViolationChecker because internally the validation template is used. Just use the curly bracket expression as expected validation violation, i.e.

		ValidationViolationChecker.checkExpectedValidationViolations(violations, Arrays
				.asList("{error.1}", "{error.2}", "{error.3}"));

Building from source

validation-violation-checker is a Maven project, so nothing special is needed here

mvn clean install

should do the job.

If a new release needs to be built and released in the Maven central repository, just run

mvn clean install -P release-build

and a new PGP signed jar is created.