BeforeEachCallback and AfterEachCallback in JUnit - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to implement a JUnit extension that runs code before each test.

JUnit

public class MyExtension implements BeforeEachCallback {
    @Override
    public void [1](ExtensionContext context) throws Exception {
        System.out.println("Before each test");
    }
}

Drag options to blanks, or click blank then click option'

AbeforeEach

BbeforeAll

CafterEach

DafterAll

Attempts:

3 left

💡 Hint

Common Mistakes

Using afterEach instead of beforeEach

Using beforeAll which runs once before all tests

The method to override in BeforeEachCallback is beforeEach, which runs before each test method.

2fill in blank

medium

Complete the code to implement a JUnit extension that runs code after each test.

JUnit

public class MyExtension implements AfterEachCallback {
    @Override
    public void [1](ExtensionContext context) throws Exception {
        System.out.println("After each test");
    }
}

Drag options to blanks, or click blank then click option'

AbeforeEach

BafterEach

CbeforeAll

DafterAll

Attempts:

3 left

💡 Hint

Common Mistakes

Using beforeEach instead of afterEach

Using afterAll which runs once after all tests

The method to override in AfterEachCallback is afterEach, which runs after each test method.

3fill in blank

hard

Fix the error in the method signature to correctly implement BeforeEachCallback.

JUnit

public class MyExtension implements BeforeEachCallback {
    @Override
    public void [1] {
        System.out.println("Before each test");
    }
}

Drag options to blanks, or click blank then click option'

AafterEach(ExtensionContext context) throws Exception

BbeforeEach()

CbeforeAll(ExtensionContext context)

DbeforeEach(ExtensionContext context) throws Exception

Attempts:

3 left

💡 Hint

Common Mistakes

Omitting the ExtensionContext parameter

Not declaring throws Exception

The beforeEach method must accept ExtensionContext and declare throws Exception to correctly override the interface method.

4fill in blank

hard

Fill both blanks to implement a JUnit extension that prints messages before and after each test.

JUnit

public class MyExtension implements BeforeEachCallback, AfterEachCallback {
    @Override
    public void [1](ExtensionContext context) throws Exception {
        System.out.println("Starting test");
    }

    @Override
    public void [2](ExtensionContext context) throws Exception {
        System.out.println("Finished test");
    }
}

Drag options to blanks, or click blank then click option'

AbeforeEach

BafterAll

CafterEach

DbeforeAll

Attempts:

3 left

💡 Hint

Common Mistakes

Using beforeAll or afterAll which run once per test class

Swapping beforeEach and afterEach method names

beforeEach runs before each test, afterEach runs after each test. These are the correct method names for the respective interfaces.

5fill in blank

hard

Fill all three blanks to create a JUnit extension that logs before each test, after each test, and handles exceptions.

JUnit

public class LoggingExtension implements BeforeEachCallback, AfterEachCallback {
    @Override
    public void [1](ExtensionContext context) throws Exception {
        System.out.println("Log start: " + context.getDisplayName());
    }

    @Override
    public void [2](ExtensionContext context) throws Exception {
        System.out.println("Log end: " + context.getDisplayName());
    }

    public void handleException(Throwable [3]) {
        System.out.println("Exception caught: " + [3].getMessage());
    }
}

Drag options to blanks, or click blank then click option'

AbeforeEach

BafterEach

Cex

Dexception

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong method names for the interface methods

Using invalid variable names for the exception parameter

The methods beforeEach and afterEach are from the interfaces. The exception parameter name can be any valid identifier; here 'ex' is used.