Mockito dependency setup in JUnit - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Mockito Dependency in Maven

Which Maven dependency snippet correctly adds Mockito version 4.11.0 to a JUnit 5 project?

A

<dependency>
  <groupId>org.mockito</groupId>
  <artifactId>mockito-core</artifactId>
  <version>4.11.0</version>
  <scope>test</scope>
</dependency>

B

<dependency>
  <groupId>org.mockito</groupId>
  <artifactId>mockito-all</artifactId>
  <version>4.11.0</version>
</dependency>

C

<dependency>
  <groupId>org.mockito</groupId>
  <artifactId>mockito-junit-jupiter</artifactId>
  <version>4.11.0</version>
  <scope>test</scope>
</dependency>

D

<dependency>
  <groupId>org.mockito</groupId>
  <artifactId>mockito-core</artifactId>
  <version>3.5.0</version>
  <scope>compile</scope>
</dependency>

💡 Hint

Mockito core is the main library; use the latest version and test scope for testing.

Option A correctly uses mockito-core version 4.11.0 with test scope, which is the recommended setup for JUnit 5 projects. Option A uses mockito-all which is deprecated. Option A uses an older version and a different artifact. Option A uses an older version and wrong scope.

❓ Predict Output

intermediate

JUnit 5 Test Execution with Mockito Dependency

Given the following JUnit 5 test class using Mockito, what will be the test execution result if Mockito dependency is missing from the project?

JUnit

import org.junit.jupiter.api.Test;
import org.mockito.Mockito;

public class SampleTest {
    @Test
    void testMock() {
        Runnable mockRunnable = Mockito.mock(Runnable.class);
        Mockito.verify(mockRunnable, Mockito.never()).run();
    }
}

A Test passes successfully.

B Test fails with a NullPointerException.

C Test fails with an AssertionError.

D Test fails with a ClassNotFoundException for Mockito classes.

💡 Hint

Think about what happens if the Mockito classes are not found at runtime.

Without the Mockito dependency, the JVM cannot find Mockito classes, causing a ClassNotFoundException during test execution.

❓ locator

advanced

Correct Mockito Dependency for Gradle Build

Which Gradle dependency line correctly adds Mockito version 4.11.0 for testing in a Java project?

A implementation 'org.mockito:mockito-core:4.11.0'

B testImplementation 'org.mockito:mockito-core:4.11.0'

C compileOnly 'org.mockito:mockito-core:4.11.0'

D runtimeOnly 'org.mockito:mockito-core:4.11.0'

💡 Hint

Mockito is used only during testing, so use the testImplementation configuration.

Option B uses testImplementation which is correct for test dependencies in Gradle. Option B includes Mockito in main code which is unnecessary. Options A and C are incorrect scopes for Mockito usage.

❓ assertion

advanced

Mockito Version Compatibility Assertion

Which assertion correctly verifies that the Mockito version used in the project is at least 4.0.0 in a Java test?

JUnit

import static org.junit.jupiter.api.Assertions.assertTrue;
import org.mockito.Mockito;

public class VersionTest {
    @org.junit.jupiter.api.Test
    void testMockitoVersion() {
        String version = Mockito.class.getPackage().getImplementationVersion();
        // Insert assertion here
    }
}

A assertTrue(version.equals("4.0.0"));

B assertTrue(version.startsWith("4"));

C assertTrue(version.compareTo("4.0.0") >= 0);

D assertTrue(version.compareTo("3.9.9") > 0);

💡 Hint

Use string comparison to check version is equal or higher than 4.0.0.

Option C correctly asserts that the version string is lexicographically greater or equal to "4.0.0", ensuring version 4 or higher. Option C only checks if version starts with 4, which may miss minor versions. Option C requires exact match. Option C checks greater than 3.9.9 but excludes 4.0.0 itself.

❓ framework

expert

Mockito Extension Setup for JUnit 5

Which code snippet correctly enables Mockito annotations like @Mock in a JUnit 5 test class?

A

@ExtendWith(MockitoExtension.class)
public class MyTest {
  @Mock
  private List<String> mockList;

  @Test
  void test() {
    Mockito.when(mockList.size()).thenReturn(5);
    assertEquals(5, mockList.size());
  }
}

B

@RunWith(MockitoJUnitRunner.class)
public class MyTest {
  @Mock
  private List<String> mockList;

  @Test
  void test() {
    Mockito.when(mockList.size()).thenReturn(5);
    assertEquals(5, mockList.size());
  }
}

C

public class MyTest {
  @Mock
  private List<String> mockList;

  @BeforeEach
  void init() {
    MockitoAnnotations.openMocks(this);
  }

  @Test
  void test() {
    Mockito.when(mockList.size()).thenReturn(5);
    assertEquals(5, mockList.size());
  }
}

D

public class MyTest {
  private List<String> mockList = Mockito.mock(List.class);

  @Test
  void test() {
    Mockito.when(mockList.size()).thenReturn(5);
    assertEquals(5, mockList.size());
  }
}

💡 Hint

JUnit 5 uses @ExtendWith for extensions, not @RunWith.

Option A correctly uses @ExtendWith(MockitoExtension.class) to enable Mockito annotations in JUnit 5. Option A uses @RunWith which is for JUnit 4. Option A manually opens mocks but does not use the extension. Option A manually creates mocks without annotations.