Cypress Preserve Cookies

NOTE: Preserve Once in cypress is deprecated as of version 9.7.0, and instead, an experimental cypress session can be used to preserve/save cookies with experimental mode turned on.

In this article, however, we will cover what preserve once is and how it was used. Later cy.session() will be covered in a separate article for clear understanding.

Cypress allows you to preserve or save cookies for multiple tests by using the preserve cookies command.
This will make the test even faster by preloading each test with previously saved sessions.
Cypress typically clears every cookie before each new test and starts a clean slate.
This makes tests sluggish as they start new every time after the visit.
Preserving cookies and using that later on in other tests will make tests fast.

Syntax:

Cypress.Cookies.preserveOnce(names...)

Arguments:

Names: Name of the cookies to be preserved. An unlimited number of args can be passed.

Correct Use:

cy.cookies.preserveOnce()

describe('Dashboard', () => {
 beforeEach(() => {
   Cypress.Cookies.preserveOnce('session_id', 'remember_token')
 })
 it('Login', () => {
   // ...
 })
 it('Add to cart', () => {
   // ...
 })

Consider this test where we have used preserve once before each so that it may preserve session id and retains when it goes on to the next step.

Set Globally:

Cookies can be preserved globally, which will always be preserved across each test.

Preserve String:

Cypress.Cookies.defaults({
 preserve: 'session,'
})

Any cookies with the name 'session' will be preserved globally and won't be cleared after each test.

Array Preserve:

Cypress.Cookies.defaults({
 preserve: ['session,' 'api_token'],
})

Arrays of cookies can be passed so that tests will remember these cookies when they come across them.

RegExp Preserve:

Cypress.Cookies.defaults({
 preserve: /session/token/,
})

Now any cookie with this regular expression will be remembered.

Function Preserve:

Cypress.Cookies.defaults({
 preserve: (cookie) => {
 },
})

Own logic can be implemented within this body, and if the function is truthy, the cookie won't be cleared before each run of tests.