beforeEach and afterEach hooks in Cypress - Test Execution Trace

Test Overview

This test suite uses beforeEach to visit the homepage before each test and afterEach to clear cookies after each test. It verifies the page title and the presence of a login button.

Test Code - Cypress

Cypress

describe('Homepage tests with hooks', () => {
  beforeEach(() => {
    cy.visit('https://example.cypress.io')
  })

  afterEach(() => {
    cy.clearCookies()
  })

  it('checks the page title', () => {
    cy.title().should('include', 'Kitchen Sink')
  })

  it('checks the login button is visible', () => {
    cy.get('button#login').should('be.visible')
  })
})

Execution Trace - 7 Steps

Step	Action	System State	Assertion	Result
1	Test suite starts	No browser opened yet	—	PASS
2	beforeEach hook runs: cy.visit('https://example.cypress.io')	Browser opens and navigates to https://example.cypress.io homepage	—	PASS
3	Test 1 runs: cy.title().should('include', 'Kitchen Sink')	Homepage loaded with title containing 'Kitchen Sink'	Page title includes 'Kitchen Sink'	PASS
4	afterEach hook runs: cy.clearCookies()	Cookies cleared from browser	—	PASS
5	beforeEach hook runs again: cy.visit('https://example.cypress.io')	Browser reloads homepage	—	PASS
6	Test 2 runs: cy.get('button#login').should('be.visible')	Homepage loaded with login button visible	Login button with id 'login' is visible	PASS
7	afterEach hook runs again: cy.clearCookies()	Cookies cleared from browser	—	PASS

Failure Scenario

Failing Condition: The login button with id 'login' is not present or not visible on the page

Execution Trace Quiz - 3 Questions

What does the beforeEach hook do in this test suite?

A Checks the page title

B Visits the homepage before each test

C Clears cookies after each test

D Clicks the login button

Key Result

Using beforeEach and afterEach hooks helps keep tests clean and independent by setting up and cleaning up the test environment automatically before and after each test.

Practice

1. What is the main purpose of the beforeEach hook in Cypress testing?

easy

A. To run code before every test to set up the test environment

B. To run code after every test to clean up the test environment

C. To skip a test conditionally

D. To group multiple tests together

Solution

1. Step 1: Understand the role of beforeEach

   The beforeEach hook runs before each test to prepare the environment or state needed for the test.

2. Step 2: Differentiate from afterEach

   Unlike afterEach, which runs after tests to clean up, beforeEach sets up conditions before tests.

3. Final Answer:

   To run code before every test to set up the test environment -> Option A

4. Quick Check:

   beforeEach = setup before tests [OK]

Hint: Remember: beforeEach runs before tests, afterEach runs after [OK]

Common Mistakes:

• Confusing beforeEach with afterEach
• Thinking beforeEach skips tests
• Assuming beforeEach groups tests

2. Which of the following is the correct syntax to use afterEach in a Cypress test file?

easy

A. afterEach { cy.visit('/home') }

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

C. afterEach: () => cy.visit('/home')

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

Solution

1. Step 1: Recall correct function syntax in Cypress

   Cypress hooks use function calls with arrow functions inside parentheses, like afterEach(() => { ... }).

2. Step 2: Identify syntax errors in other options

   Options B, C, and D miss parentheses or use incorrect arrow function syntax.

3. Final Answer:

   afterEach(() => { cy.visit('/home') }) -> Option B

4. Quick Check:

   Hook syntax = function call with arrow function [OK]

Hint: Hooks need parentheses and arrow functions: hook(() => {}) [OK]

Common Mistakes:

• Omitting parentheses after hook name
• Using curly braces without parentheses
• Incorrect arrow function syntax

3. Consider this Cypress test code:

describe('My Tests', () => {
  beforeEach(() => {
    cy.visit('/login')
  })

  it('Test 1', () => {
    cy.get('#username').type('user1')
  })

  it('Test 2', () => {
    cy.get('#username').type('user2')
  })
})

How many times will cy.visit('/login') run when these tests execute?

medium

A. Once before all tests

B. Twice, once after each test

C. Twice, once before each test

D. Once after all tests

Solution

1. Step 1: Understand beforeEach behavior

   The beforeEach hook runs before every individual test inside the describe block.

2. Step 2: Count the tests and hook calls

   There are two tests, so cy.visit('/login') runs twice, once before each test.

3. Final Answer:

   Twice, once before each test -> Option C

4. Quick Check:

   beforeEach runs before every test [OK]

Hint: Count tests; beforeEach runs before each one [OK]

Common Mistakes:

• Thinking beforeEach runs only once
• Confusing beforeEach with afterEach
• Assuming hooks run after tests

4. You wrote this Cypress test:

describe('Sample', () => {
  beforeEach(() => {
    cy.visit('/dashboard')
  })

  afterEach(() => {
    cy.clearCookies
  })

  it('checks title', () => {
    cy.title().should('include', 'Dashboard')
  })
})

Why does cy.clearCookies not run after the test?

medium

A. Because cy.clearCookies is missing parentheses to call the function

B. Because afterEach only runs before tests

C. Because cy.clearCookies is not a valid Cypress command

D. Because beforeEach overrides afterEach

Solution

1. Step 1: Check the afterEach hook code

   The code uses cy.clearCookies without parentheses, so the function is not called.

2. Step 2: Understand function call syntax

   To execute the command, parentheses are required: cy.clearCookies().

3. Final Answer:

   Because cy.clearCookies is missing parentheses to call the function -> Option A

4. Quick Check:

   Functions need () to run [OK]

Hint: Always add () to call Cypress commands [OK]

Common Mistakes:

• Forgetting parentheses on Cypress commands
• Confusing beforeEach and afterEach roles
• Assuming afterEach runs before tests

5. You want to test a form that requires logging in before each test and clearing local storage after each test. Which is the best way to organize your Cypress hooks?

hard

A. Use only beforeEach for both login and clearing local storage

B. Use afterEach to log in and beforeEach to clear local storage

C. Use only afterEach for both login and clearing local storage

D. Use beforeEach to log in and afterEach to clear local storage

Solution

1. Step 1: Identify setup and cleanup tasks

   Logging in is setup needed before each test; clearing local storage is cleanup after each test.

2. Step 2: Assign tasks to correct hooks

   Use beforeEach for setup (login) and afterEach for cleanup (clear local storage).

3. Final Answer:

   Use beforeEach to log in and afterEach to clear local storage -> Option D

4. Quick Check:

   Setup beforeEach, cleanup afterEach [OK]

Hint: Setup in beforeEach, cleanup in afterEach [OK]

Common Mistakes:

• Mixing setup and cleanup in wrong hooks
• Using only one hook for both tasks
• Not cleaning up after tests