Cypress architecture (runs in browser) - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the main environment where Cypress tests run?

Cypress tests run directly inside the browser, the same place where your application runs. This allows Cypress to control and observe the app closely.

intermediate

How does Cypress communicate with the browser during test execution?

Cypress uses a special server and a driver inside the browser to send commands and receive information, enabling real-time control and feedback.

beginner

Why is running tests inside the browser beneficial in Cypress?

Running tests inside the browser lets Cypress see everything the user sees, making it easier to catch UI bugs and interact with the app naturally.

beginner

What role does the Cypress Test Runner play in the architecture?

The Test Runner is the user interface that shows tests running in real time inside the browser, letting you watch commands and app behavior step-by-step.

intermediate

Explain how Cypress handles asynchronous commands in its architecture.

Cypress queues commands and runs them one by one inside the browser, automatically waiting for each to finish before moving on, so you don't need manual waits.

Where do Cypress tests execute?

A Inside the browser alongside the application

B On a separate server outside the browser

C Only in the command line interface

D In a virtual machine

Cypress runs tests inside the browser, allowing direct interaction with the app.

What does the Cypress Test Runner display?

A Only test results summary

B Database queries

C Server logs

D Real-time test execution inside the browser

The Test Runner shows tests running live inside the browser with detailed command info.

How does Cypress handle waiting for commands to finish?

A Runs all commands simultaneously

B Requires manual wait commands

C Automatically queues and waits for each command

D Ignores command completion

Cypress automatically queues commands and waits for each to complete before continuing.

Which component helps Cypress communicate with the browser?

A Command line tool

B Browser driver inside the browser

C Database connector

D External API server

Cypress uses a driver inside the browser to send and receive commands.

Why is running tests inside the browser useful?

A It allows direct observation and control of the app

B It speeds up server response

C It reduces browser memory usage

D It hides the app from the user

Running tests inside the browser lets Cypress see and control the app like a real user.

Describe the main components of Cypress architecture and how they work together inside the browser.

Think about how Cypress controls the app and shows test progress.

Explain why Cypress running tests inside the browser is different from other testing tools.

Compare Cypress to tools that run tests outside the browser.

Practice

1. What is a key feature of Cypress architecture regarding where tests run?

easy

A. Tests run on a cloud service without local browser access.

B. Tests run only on the server without browser interaction.

C. Tests run in a separate virtual machine outside the browser.

D. Tests run inside the browser, controlling the app like a real user.

Solution

1. Step 1: Understand Cypress test execution environment

   Cypress runs tests directly inside the browser, allowing it to control and observe the app as a user would.

2. Step 2: Compare with other options

   Other options describe architectures not used by Cypress, such as server-only or cloud-only test runs.

3. Final Answer:

   Tests run inside the browser, controlling the app like a real user. -> Option D

4. Quick Check:

   Cypress tests run in browser = A [OK]

Hint: Remember: Cypress tests run inside the browser environment [OK]

Common Mistakes:

• Thinking tests run only on the server
• Assuming tests run outside the browser
• Confusing Cypress with cloud-only test runners

2. Which of the following is the correct way to write a Cypress command to visit a webpage?

easy

A. cy.visit('https://example.com')

B. visit.cy('https://example.com')

C. cy.goTo('https://example.com')

D. browser.visit('https://example.com')

Solution

1. Step 1: Recall Cypress command syntax

   Cypress commands start with cy. followed by the command name, so cy.visit() is correct.

2. Step 2: Check other options for syntax errors

   Options A, B, and D use incorrect method names or object references not valid in Cypress.

3. Final Answer:

   cy.visit('https://example.com') -> Option A

4. Quick Check:

   Correct Cypress command syntax = C [OK]

Hint: Cypress commands always start with 'cy.' [OK]

Common Mistakes:

• Swapping method and object order
• Using non-existent Cypress commands
• Using browser object instead of cy

3. Given the following Cypress test code, what will be the output in the test runner?

describe('My Test', () => {
  it('checks page title', () => {
    cy.visit('https://example.cypress.io')
    cy.title().should('include', 'Kitchen')
  })
})

medium

A. Test throws a syntax error due to missing semicolons.

B. Test passes if the page title includes 'Kitchen'.

C. Test passes regardless of the page title content.

D. Test fails because cy.title() is not a valid command.

Solution

1. Step 1: Understand the test steps

   The test visits the Cypress example page and asserts the page title includes the word 'Kitchen'.

2. Step 2: Validate command correctness and assertion

   cy.title() is a valid Cypress command that gets the page title. The assertion should('include', 'Kitchen') checks if the title contains 'Kitchen'.

3. Final Answer:

   Test passes if the page title includes 'Kitchen'. -> Option B

4. Quick Check:

   cy.title() assertion success = D [OK]

Hint: cy.title() gets page title; check with should() [OK]

Common Mistakes:

• Thinking cy.title() is invalid
• Ignoring assertion logic
• Confusing syntax errors with missing semicolons

4. Identify the error in this Cypress test code snippet:

it('checks button click', () => {
  cy.visit('https://example.com')
  cy.get('#submit').click
})

medium

A. Incorrect selector syntax for cy.get().

B. cy.visit() should be inside beforeEach block.

C. Missing parentheses after click command.

D. Using cy.get() without chaining should() causes error.

Solution

1. Step 1: Review the click command usage

   The click command must be called as a function with parentheses: click().

2. Step 2: Check other parts of the code

   The selector #submit is valid, cy.visit() can be inside the test, and chaining should() is optional.

3. Final Answer:

   Missing parentheses after click command. -> Option C

4. Quick Check:

   click() needs parentheses = B [OK]

Hint: Always call commands like click() with parentheses [OK]

Common Mistakes:

• Forgetting parentheses on commands
• Misunderstanding selector syntax
• Thinking visit() must be in beforeEach

5. Why does Cypress run tests inside the browser instead of outside it, and what advantage does this provide?

hard

A. Running inside the browser allows Cypress to control the app like a user, making tests faster and easier to debug.

B. Running inside the browser reduces network traffic by avoiding server calls.

C. Running outside the browser is impossible due to browser security restrictions.

D. Running inside the browser enables tests to run without any JavaScript.

Solution

1. Step 1: Understand Cypress architecture purpose

   Cypress runs tests inside the browser to interact with the app as a real user would, giving precise control and observation.

2. Step 2: Identify benefits of this approach

   This approach makes tests fast, reliable, and easy to debug because Cypress can directly access the app's DOM and network.

3. Final Answer:

   Running inside the browser allows Cypress to control the app like a user, making tests faster and easier to debug. -> Option A

4. Quick Check:

   Browser test run = faster, easier debug = A [OK]

Hint: Tests inside browser = real user control + fast debugging [OK]

Common Mistakes:

• Thinking tests run outside browser for speed
• Confusing network traffic with test speed
• Believing tests run without JavaScript