Task command for Node operations in Cypress - Test Execution Trace

Test Overview

This test uses Cypress task command to perform a Node.js operation that reads a file's content. It verifies that the content returned by the task matches the expected text.

Test Code - Cypress

Cypress

/// <reference types="cypress" />

// In cypress/plugins/index.js or cypress.config.js
module.exports = (on, config) => {
  on('task', {
    readFileContent(filename) {
      const fs = require('fs')
      return fs.readFileSync(filename, 'utf8')
    }
  })
}

// In the test file
describe('Task command for Node operations', () => {
  it('reads file content using task command', () => {
    const testFile = 'cypress/fixtures/sample.txt'
    cy.task('readFileContent', testFile).then((content) => {
      expect(content).to.contain('Hello Cypress')
    })
  })
})

Execution Trace - 7 Steps

Step	Action	System State	Assertion	Result
1	Test starts	Cypress test runner initialized	-	PASS
2	Cypress opens browser and loads test page	Browser opened with Cypress test environment	-	PASS
3	Test calls cy.task('readFileContent', 'cypress/fixtures/sample.txt')	Cypress sends task request to Node process	-	PASS
4	Node process executes task: reads file content synchronously	File 'sample.txt' content read: 'Hello Cypress! This is a sample file.'	-	PASS
5	Task returns file content to Cypress test	Cypress receives file content string	-	PASS
6	Test asserts content includes 'Hello Cypress'	Content string contains expected text	expect(content).to.contain('Hello Cypress')	PASS
7	Test ends successfully	Test passed, no errors	-	PASS

Failure Scenario

Failing Condition: The file 'cypress/fixtures/sample.txt' does not exist or path is incorrect

Execution Trace Quiz - 3 Questions

What does the cy.task command do in this test?

A Clicks a button on the webpage

B Navigates to a new URL

C Runs a Node.js function to read a file and returns its content

D Types text into an input field

Key Result

Using Cypress task commands allows running Node.js code during tests, enabling operations like file reading that are not possible in the browser context.