JUnit 4 vs JUnit 5 (Jupiter) differences - Practice Questions

Challenge - 5 Problems

🧠 Conceptual

intermediate

JUnit 4 vs JUnit 5: Annotation Differences

Which annotation is used in JUnit 5 to replace JUnit 4's @Before annotation for setup methods?

A @Init

B @BeforeAll

C @BeforeEach

D @Setup

💡 Hint

JUnit 5 renamed lifecycle annotations to be more descriptive per test method or all tests.

JUnit 4 uses @Before to run setup before each test method. JUnit 5 replaces this with @BeforeEach to clarify it runs before each test.

❓ Predict Output

intermediate

JUnit 5 Test Execution Result

What will be the test execution result of this JUnit 5 test class?

JUnit

import org.junit.jupiter.api.Test;
import static org.junit.jupiter.api.Assertions.assertEquals;

public class SampleTest {
    @Test
    void testSum() {
        assertEquals(5, 2 + 3);
    }
}

A Test fails with AssertionError

B Test passes

C Compilation error due to missing @RunWith

D Test ignored

💡 Hint

JUnit 5 does not require @RunWith for basic tests.

The test method asserts 2 + 3 equals 5, which is true, so the test passes.

❓ assertion

advanced

Correct Assertion for Exception Testing in JUnit 5

Which assertion correctly tests that a method throws NullPointerException in JUnit 5?

JUnit

public void methodThatThrows() {
    throw new NullPointerException();
}

A assertException(NullPointerException.class, () -> methodThatThrows());

B @Test(expected = NullPointerException.class) public void test() { methodThatThrows(); }

C assertThatThrownBy(() -> methodThatThrows()).isInstanceOf(NullPointerException.class);

D assertThrows(NullPointerException.class, () -> methodThatThrows());

💡 Hint

JUnit 5 uses assertThrows for exception testing.

JUnit 5 uses assertThrows to check exceptions. Option D is JUnit 4 style and won't compile in JUnit 5 without vintage engine.

❓ framework

advanced

JUnit 5 Modular Architecture

Which statement best describes JUnit 5's architecture compared to JUnit 4?

A JUnit 5 is composed of three modules: Jupiter, Vintage, and Platform.

B JUnit 5 uses the same runner mechanism as JUnit 4.

C JUnit 5 requires no dependencies and runs standalone.

D JUnit 5 is a single monolithic jar replacing JUnit 4.

💡 Hint

JUnit 5 separates concerns into modules for flexibility.

JUnit 5 consists of the Jupiter module for new tests, Vintage for backward compatibility, and Platform for launching tests.

🔧 Debug

expert

JUnit 5 Test Not Executing

Given this JUnit 5 test class, why does the test method not run?

JUnit

import org.junit.jupiter.api.Test;

public class MyTest {
    public void testMethod() {
        System.out.println("Running test");
    }
}

A The test method is missing the @Test annotation.

B The test method must be static.

C The class must extend a JUnit 5 base test class.

D JUnit 5 requires test methods to be public static void.

💡 Hint

JUnit 5 identifies tests by annotations, not method names.

JUnit 5 runs methods annotated with @Test. Without it, the method is ignored.