before and after hooks in Cypress - Build an Automation Script

Verify user login and logout with setup and cleanup hooks

Preconditions (2)

Step 1: Before all tests, open the login page

Step 2: Before each test, ensure the user is logged out

Step 3: Enter 'testuser' in the username field

Step 4: Enter 'Test@1234' in the password field

Step 5: Click the login button

Step 6: Verify the URL changes to the dashboard page

Step 7: After each test, log out the user

Step 8: After all tests, close the browser session

✅ Expected Result: User successfully logs in and logs out for each test, with setup and cleanup done automatically before and after tests

Automation Requirements - Cypress

Assertions Needed:

Verify URL is 'https://example.com/dashboard' after login

Verify logout button is visible after login

Verify user is redirected to login page after logout

Best Practices:

Use before() hook to open login page once before all tests

Use beforeEach() hook to ensure user is logged out before each test

Use afterEach() hook to log out user after each test

Use after() hook to perform any cleanup if needed

Use clear and stable selectors for elements

Avoid hardcoded waits; use Cypress commands for synchronization

Automated Solution

Cypress

describe('User Login and Logout Tests with Hooks', () => {
  before(() => {
    // Runs once before all tests
    cy.visit('https://example.com/login');
  });

  beforeEach(() => {
    // Ensure user is logged out before each test
    cy.get('body').then(($body) => {
      if ($body.find('#logout-button').length) {
        cy.get('#logout-button').click();
        cy.url().should('include', '/login');
      }
    });
  });

  it('should log in successfully', () => {
    cy.get('#username').clear().type('testuser');
    cy.get('#password').clear().type('Test@1234');
    cy.get('#login-button').click();
    cy.url().should('eq', 'https://example.com/dashboard');
    cy.get('#logout-button').should('be.visible');
  });

  afterEach(() => {
    // Log out after each test if logged in
    cy.get('body').then(($body) => {
      if ($body.find('#logout-button').length) {
        cy.get('#logout-button').click();
        cy.url().should('include', '/login');
      }
    });
  });

  after(() => {
    // Cleanup if needed after all tests
    // For Cypress, usually no action needed here
  });
});

The before() hook runs once before all tests to open the login page.

The beforeEach() hook checks if the user is logged in by looking for the logout button. If found, it clicks logout to ensure a clean state before each test.

The test case enters username and password, clicks login, then verifies the URL and logout button visibility.

The afterEach() hook logs out the user after each test if logged in, ensuring no leftover session affects other tests.

The after() hook is included for completeness but is empty because Cypress handles cleanup automatically.

This structure keeps tests independent and reliable by managing setup and cleanup with hooks.

Common Mistakes - 4 Pitfalls

Not using beforeEach to reset state before each test

Using hardcoded waits like cy.wait(5000)

Not checking if user is logged in before clicking logout

{'mistake': 'Putting all test steps inside before() hook', 'why_bad': "before() runs once, so tests won't run independently.", 'correct_approach': 'Use before() only for setup, keep test steps inside it() blocks.'}

Bonus Challenge

Now add data-driven testing with 3 different username and password combinations

Show Hint

Practice

1. What is the main purpose of before and after hooks in Cypress testing?

easy

A. To define test data inside tests

B. To write the main test steps

C. To skip tests conditionally

D. To run setup and cleanup code once per test suite

Solution

1. Step 1: Understand the role of hooks

   Hooks like before and after run code automatically before or after tests.

2. Step 2: Identify their scope

   before and after run once per test suite, ideal for setup and cleanup.

3. Final Answer:

   To run setup and cleanup code once per test suite -> Option D

4. Quick Check:

   Hooks run code around tests = D [OK]

Hint: Remember: before/after run once per suite, beforeEach/afterEach per test [OK]

Common Mistakes:

• Confusing before with beforeEach
• Thinking hooks run inside tests
• Using hooks to skip tests

2. Which of the following is the correct syntax to run a function once before all tests in a Cypress test suite?

easy

A. before(() => { cy.visit('/') })

B. beforeEach(() => { cy.visit('/') })

C. after(() => { cy.visit('/') })

D. afterEach(() => { cy.visit('/') })

Solution

1. Step 1: Identify the hook that runs once before all tests

   before runs once before the entire suite; beforeEach runs before each test.

2. Step 2: Match the syntax

   before(() => { cy.visit('/') }) is the correct syntax to run once before all tests.

3. Final Answer:

   before(() => { cy.visit('/') }) -> Option A

4. Quick Check:

   Run once before all tests = before() = A [OK]

Hint: Use before() for once before all tests, beforeEach() for every test [OK]

Common Mistakes:

• Using beforeEach instead of before for once-per-suite setup
• Confusing after with before
• Incorrect arrow function syntax

3. Consider this Cypress code snippet:

describe('My Suite', () => {
  before(() => {
    cy.log('Setup once')
  })
  beforeEach(() => {
    cy.log('Setup before each test')
  })
  it('Test 1', () => {
    cy.log('Running Test 1')
  })
  it('Test 2', () => {
    cy.log('Running Test 2')
  })
})

What is the order of logs printed during test execution?

medium

A. Setup before each test, Setup once, Running Test 1, Running Test 2

B. Setup once, Setup before each test, Running Test 1, Setup before each test, Running Test 2

C. Running Test 1, Setup once, Setup before each test, Running Test 2

D. Setup once, Running Test 1, Setup before each test, Running Test 2

Solution

1. Step 1: Understand hook execution order

   before runs once before all tests, beforeEach runs before each test.

2. Step 2: Trace the logs

   Logs print in this order: 'Setup once' (before all), then for Test 1: 'Setup before each test', 'Running Test 1', then for Test 2: 'Setup before each test', 'Running Test 2'.

3. Final Answer:

   Setup once, Setup before each test, Running Test 1, Setup before each test, Running Test 2 -> Option B

4. Quick Check:

   before runs once, beforeEach runs before each test = A [OK]

Hint: Remember: before runs once, beforeEach runs before every test [OK]

Common Mistakes:

• Thinking beforeEach runs only once
• Mixing order of logs
• Ignoring before hook

4. You wrote this Cypress test code:

describe('Test Suite', () => {
  beforeEach(() => {
    cy.visit('/home')
  })
  after(() => {
    cy.clearCookies()
  })
  it('Test A', () => {
    cy.get('#btn').click()
  })
  it('Test B', () => {
    cy.get('#btn').click()
  })
})

But the cy.clearCookies() is not running after each test as expected. What is the problem?

medium

A. after runs once after all tests, not after each test

B. You must call cy.clearCookies() inside each test manually

C. after should be afterEach to run after each test

D. beforeEach should be before to clear cookies

Solution

1. Step 1: Understand the difference between after and afterEach

   after runs once after all tests; afterEach runs after each test.

2. Step 2: Identify the problem

   after runs once after all tests, not after each test.

3. Final Answer:

   after runs once after all tests, not after each test -> Option A

4. Quick Check:

   after runs once per suite = A [OK]

Hint: Use afterEach for per-test cleanup, after for once after all tests [OK]

Common Mistakes:

• Using after instead of afterEach for per-test cleanup
• Expecting after to run multiple times
• Manually clearing cookies inside tests

5. You want to run a setup step once before all tests, a cleanup step once after all tests, and also run a login step before each test in Cypress. Which code snippet correctly implements this?

hard

A. beforeEach(() => { cy.setup() }); afterEach(() => { cy.cleanup() }); before(() => { cy.login() });

B. before(() => { cy.login() }); afterEach(() => { cy.cleanup() }); beforeEach(() => { cy.setup() });

C. before(() => { cy.setup() }); after(() => { cy.cleanup() }); beforeEach(() => { cy.login() });

D. after(() => { cy.setup() }); before(() => { cy.cleanup() }); afterEach(() => { cy.login() });

Solution

1. Step 1: Assign setup and cleanup hooks

   Setup runs once before all tests using before, cleanup runs once after all tests using after.

2. Step 2: Assign login before each test

   Login runs before each test using beforeEach.

3. Step 3: Verify correct order and usage

   before(() => { cy.setup() }); after(() => { cy.cleanup() }); beforeEach(() => { cy.login() }); correctly uses before, after, and beforeEach for these steps.

4. Final Answer:

   before(() => { cy.setup() }); after(() => { cy.cleanup() }); beforeEach(() => { cy.login() }); -> Option C

5. Quick Check:

   Setup once before, cleanup once after, login before each = B [OK]

Hint: Use before for setup, after for cleanup, beforeEach for per-test login [OK]

Common Mistakes:

• Mixing beforeEach with once-per-suite hooks
• Placing login in before or after hooks incorrectly
• Swapping setup and cleanup hooks