How do I keep writing in the same JSON file within cypress? - testing

Question

I'm currently setting up a test scenario that allows me to create a random email, and I would like to do more series of tests and keep writing on the same JSON file instead of overwriting what I already sent to the JSON files. Meaning that I would like to use the same JSON file to save all of the emails that I created with my tests.
Does anyone knows a better way to do this?
Cypress.Commands.add("form", ()=> {
// fill-out form
function makeid(length) {
var result = '';
var characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
var charactersLength = characters.length;
for ( var i = 0; i < length; i++ ) {
result += characters.charAt(Math.floor(Math.random() * charactersLength));
}
return result;
}
const fullName = 'MockaData Testing'
const email = makeid(6) + "#aharo.com";
console.log(makeid(5));
cy.get('#full_name')
.type(fullName)
cy.get('#company')
.type('Testing')
cy.get('#phone_number')
.type('2022569878')
cy.get('#email')
.type(email).writeFile('cypress/fixtures/users.json', {name: fullName, email: email})
cy.get('#password')
.type('Abcd1234')
// click submit
cy.get(".app-submit-btn-text", { multiple: true }).click()
})

Answer 1

To achieve this you have to use { flag: 'a+' } (cypress docs). This will append the contents at the end of the file instead of overwriting it.
cy.writeFile('cypress/fixtures/users.json', {name: fullName, email: email}, {flag: 'a+'})