Soft assertions that do not fail JUnit test

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Post summary: Code examples how to use assertions that do not fail the unit test immediately.

Code shown in examples bellow is available in GitHub java-samples/jersey1 repository.

Unit vs Functional testing

Unit testing paradigm states that each test exercises particular code behaviour. So in a perfect world one unit test would have one assertion which defines unit test result – either passed or failed. This is why unit testing frameworks provide only asserts which stop further execution of current test method. In functional testing usually one test verifies several conditions. Not debating if this is good or bad. Assume you are doing GUI testing, once you have opened particular page you’d better do as much verification as possible to reduce the risk of bugs. Having this page opened over and over for each single check is not the most efficient way of testing. This is why when you run functional tests you need some kind of assert that indicates whether passed or failed but to let the test continue in no critical issue is present. Those are generally called “soft” asserts.

Soft assertions and JUnit

TestNG provides org.testng.asserts.SoftAssert class for soft asserts as it is more oriented towards functional testing. JUnit is unit testing framework, so it does not provide any soft assertions. In order to create such behaviour additional libraries are needed.

AssertJ

AssertJ is library providing fluent assertions. It is very similar to Hamcrest which comes by default with JUnit. Along with all the asserts AssertJ provides soft assertions with its SoftAssertions class inside org.assertj.core.api package.

Usage

Bellow is a functional test run against Dropwizard stub described in Build a RESTful stub server with Dropwizard post. Important is to instantiate new SoftAssertions object before the test verifications and to call assertAll() method in the end to collect results. Best way to do this is to use JUnit’s @Before and @After annotated methods.

package com.automationrhapsody.jersey1;

import com.automationrhapsody.jersey1.model.Person;
import com.automationrhapsody.jersey1.rules.PersonServiceJerseyClient;

import java.util.List;

import org.assertj.core.api.SoftAssertions;
import org.junit.After;
import org.junit.Before;
import org.junit.ClassRule;
import org.junit.Test;

import static org.hamcrest.MatcherAssert.assertThat;
import static org.hamcrest.core.Is.is;

public class PersonServiceTest {

	@ClassRule
	public static final PersonServiceJerseyClient CLIENT 
		= new PersonServiceJerseyClient();

	private SoftAssertions softAssertions;

	private Person person;

	@Before
	public void setUp() {
		person = new Person();
		person.setId(123);
		person.setFirstName("First Name");
		person.setLastName("Last Name");
		person.setEmail("Email");

		softAssertions = new SoftAssertions();
	}

	@After
	public void tearDown() {
		softAssertions.assertAll();
	}

	@Test
	public void testAllOperations() {
		String saveResult = CLIENT.save(person);
		assertThat(saveResult, is("Added Person with id=123"));

		Person actual = CLIENT.get(person.getId());
		softAssertions
			.assertThat(actual.getId()).isEqualTo(person.getId());
		softAssertions
			.assertThat(actual.getFirstName()).isEqualTo(person.getFirstName());
		softAssertions
			.assertThat(actual.getLastName()).isEqualTo(person.getLastName());
		softAssertions
			.assertThat(actual.getEmail()).isEqualTo(person.getEmail());

		String result = CLIENT.remove();
		assertThat(result, is("Last person remove. Total count: 4"));
	}
}

Conclusion

Soft assertions are needed in case of functional tests being run with JUnit. Since such are not available out of the box because JUnit is targeted for unit tests soft assertions can be used from external libraries such as AssertJ.

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Category: API Automation, Java, Web Automation | Tags: