Task command for Node operations in Cypress - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the task command in Cypress?

The task command lets Cypress run Node.js code outside the browser, enabling operations like file system access or database queries that the browser cannot perform.

intermediate

How do you define a custom task in Cypress?

You define a custom task inside the cypress.config.js file under the setupNodeEvents function using on('task', { ... }) and provide task names with their corresponding Node.js functions.

intermediate

Example: What does this Cypress task do?<br>

on('task', { readFile(filename) { return fs.readFileSync(filename, 'utf8') } })

This task reads the content of a file named filename synchronously and returns its text content to the Cypress test.

beginner

Why can't Cypress tests directly use Node.js modules like fs inside cy.* commands?

Because Cypress commands run inside the browser environment, which does not have access to Node.js modules. The task command bridges this gap by running Node code in the background process.

beginner

How do you call a custom task named readFile from a Cypress test?

Use cy.task('readFile', 'path/to/file.txt').then(content => { ... }) to call the task and handle the returned content asynchronously.

What is the main reason to use cy.task in Cypress?

A To run Node.js code like file operations

B To interact with DOM elements

C To send HTTP requests

D To take screenshots

cy.task is used to run Node.js code such as file system operations, which cannot be done inside the browser environment where Cypress commands run.

Where do you define custom tasks in a Cypress project?

A In <code>cypress.config.js</code> under <code>setupNodeEvents</code>

B In <code>package.json</code>

C In the browser console

D Inside the test spec files

Custom tasks are defined in cypress.config.js inside the setupNodeEvents function using on('task', { ... }).

Which of these is a valid way to call a task named getData in a Cypress test?

A cy.getData()

B cy.invoke('getData')

C cy.task('getData')

D cy.run('getData')

You call tasks using cy.task('taskName') syntax.

What kind of code runs inside the task handler in Cypress?

A Browser JavaScript

B Node.js code

C CSS styles

D HTML markup

The task handler runs Node.js code in the background process, outside the browser.

If a task returns a value, how do you access it in your Cypress test?

A Directly as a return value

B Using a callback function

C It is not possible to get return values

D Using a <code>.then()</code> after <code>cy.task()</code>

Since cy.task() is asynchronous, you use .then() to access the returned value.

Explain how Cypress task commands help in performing Node.js operations during tests.

Think about what Cypress cannot do inside the browser and how tasks solve that.

Describe the steps to create and use a custom task that reads a file content in Cypress.

Focus on where to write the task and how to call it from the test.