[FIXED] Can someone explain why assertTrue does not fail in this case?

Issue

So I have a test set up like this:

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;

import com.sam.demo.HibernateUtil;
import com.sam.entity.Student;

public class HibernateTest {
    private static SessionFactory sessionFactory;
    private Session session;

    @BeforeAll
    public static void setup() {
        sessionFactory = HibernateUtil.getSessionFactory();
    }

    @AfterAll
    public static void teardown() {
        sessionFactory.close();
    }

    @BeforeEach
    public void openSession() {
        session = sessionFactory.getCurrentSession();
    }

    @AfterEach
    public void closeSession() {
        session.close();
    }

    @Test
    @DisplayName("Create student in the database")
    public void testCreate() {
        try {
            Student student = new Student("Angela", "Wu", "[email protected]");
            session.beginTransaction();
            Integer id = (Integer) session.save(student);
            session.getTransaction().commit();
            Assertions.assertTrue(id > 0);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

}

I was running this test after dropping the table manually to see what result I would get. The record could not be inserted into the database because the table did not exist and I got an exception, but I was surprised to see that my test passed! can someone help me with this? I thought that the save() method won't return anything and the id won't be > 0.

My hibernate configuration is:

<?xml version="1.0" encoding="UTF-8"?>
<hibernate-configuration>
    <session-factory>
        <property name="connection.url">jdbc:mysql://localhost:3306/student_tracker?useSSL=false&amp;serverTimezone=UTC
        </property>
        <property name="connection.username">root</property>
        <property name="connection.password">password</property>
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="hibernate.show_sql">true</property>
        <property name="hibernate.format_sql">true</property>
        <property name="current_session_context_class">thread</property>

        <mapping class="com.sam.entity.Student" />

    </session-factory>
</hibernate-configuration>

Solution

You never reached your Assertions.assertTrue(id > 0); statement. As the db table was missing, commit threw an exception. You handled the exception by printing the stack trace to the console.

To let the test fail you can:

• rethrow the exception
• drop the exception handling

Your handler only prints the stack trace, but test runner does the same for uncaught exceptions, so I would go with the latter option.

As a side note, if you need to handle an exception, try to be as specific as possible - catching Exception is rarely a good idea, as it can hide unexpected ones.

Answered By - Lesiak
Answer Checked By - Marie Seifert (JavaFixing Admin)