Is there any way I can output a file from my Cypress test runner?

You can actually use cy.writeFile() as below,

cy.request('https://dummy.url').then((response) => { cy.writeFile('cypress/fixtures/response.csv', response.import.resultsCsvFileId) }) 

You can refer the docs here - https://docs.cypress.io/api/commands/writefile.html#JSON

But, this overwrite the file every time. Here, is the workaround to append the required data to a CSV file,

1. Install npm package csvdata https://www.npmjs.com/package/csvdata

   npm install --save-dev csvdata

2. In the cypress project -> plugins index.js file place the below code,

const csvdata = require('csvdata') on('task', { log(message) { csvdata.write('./logs.csv', message, { append: true, header: 'stats,numusers' }) return null } })

3. Then from now on, all the log task will get appended to the CSV file,

describe('My First Test', function() { it('Visits the Kitchen Sink', function() { cy.visit('https://example.cypress.io') cy.contains('type').then(($el) => { var data = "inService, 30"; cy.task('log', data) }) }) })

Reference: https://github.com/cypress-io/cypress/issues/1249

Update 1: The issue specified above is now resolved and append option is now available,

cy.writeFile('path/to/message.txt', 'Hello World', {flag: "a+"}))