Test lifecycle hooks (before, after) in Node.js - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the before hook in testing?

The before hook runs once before all tests in a suite. It is used to set up things needed for the tests, like initializing data or starting a server.

beginner

How does the after hook help in test suites?

The after hook runs once after all tests in a suite. It is used to clean up resources like closing database connections or stopping servers.

intermediate

What is the difference between before and beforeEach hooks?

before runs once before all tests, while beforeEach runs before each individual test. Use beforeEach to reset state before every test.

intermediate

In Node.js testing frameworks like Mocha, when would you use afterEach?

Use afterEach to run cleanup code after every test, such as resetting mocks or clearing temporary data to keep tests isolated.

beginner

Why are lifecycle hooks important in automated testing?

Lifecycle hooks help organize setup and cleanup tasks, making tests reliable and easier to maintain by avoiding repeated code and ensuring a clean test environment.

Which hook runs once before all tests in a suite?

A afterEach

B after

C beforeEach

D before

The 'before' hook runs once before all tests to set up the environment.

What is the main use of the 'after' hook?

A Run cleanup after all tests

B Initialize test data

C Run before each test

D Skip tests

The 'after' hook is used to clean up resources after all tests have run.

Which hook runs before every single test?

A beforeEach

B after

C before

D afterEach

'beforeEach' runs before each test to prepare a fresh state.

If you want to reset mocks after each test, which hook should you use?

A beforeEach

B after

C afterEach

D before

'afterEach' runs after each test, perfect for cleanup like resetting mocks.

Why avoid putting setup code inside each test instead of using lifecycle hooks?

A It makes tests slower

B It leads to repeated code and harder maintenance

C It disables test reporting

D It causes tests to fail

Using lifecycle hooks avoids repeating setup code and keeps tests clean and maintainable.

Explain how before and after hooks help manage test setup and cleanup in Node.js testing.

Think about what you do before and after a group of tasks in real life.

Describe the difference between beforeEach and afterEach hooks and when you would use them.

Consider how you prepare and clean your workspace before and after each small task.