How do I wait until a cookie is set in cypress?

When using Cypress for automated testing, it is crucial to ensure that cookies are correctly set before executing tests. Cypress offers multiple approaches to handle cookies and other asynchronous operations, ensuring they are properly managed before test cases are executed.

Using cy.setCookie() and cy.wait()

The most straightforward method is to use Cypress's cy.setCookie() command to set cookies. If you need to wait for a period to ensure the application state is correctly synchronized after setting cookies, you can combine it with cy.wait(). Example as follows:

javascript
describe('Cookie Setup Test', () => {
  it('Execute test after setting cookie', () => {
    // Visit the page
    cy.visit('https://example.com');

    // Set cookie
    cy.setCookie('session_id', '12345');

    // Wait for a period to ensure cookie is effective
    cy.wait(1000);  // Wait for 1000 milliseconds

    // Execute test that requires cookie
    cy.get('selector').should('have.text', 'Expected text');
  });
});

Using .then() to Handle Asynchronous Operations

Another approach is to utilize Cypress's .then() function to ensure subsequent actions are executed only after cookies are set. This guarantees that all actions follow the expected execution order. Example as follows:

javascript
describe('Cookie Setup Test', () => {
  it('Execute test after setting cookie', () => {
    // Visit the page
    cy.visit('https://example.com');

    // Set cookie and proceed after completion
    cy.setCookie('session_id', '12345').then(() => {
      // Cookie is now set; safely execute operations dependent on cookie
      cy.get('selector').should('have.text', 'Expected text');
    });
  });
});

Using cy.request()

If you need to ensure that some backend logic is completed before setting cookies, such as user authentication, you can use cy.request() to send requests and set cookies after the response is returned. Example as follows:

javascript
describe('Cookie Setup Test', () => {
  it('Login and execute test after setting cookie', () => {
    // Send login request
    cy.request('POST', 'https://example.com/api/login', {
      username: 'user',
      password: 'password'
    }).then((response) => {
      // Set cookie using login response data
      cy.setCookie('auth_token', response.body.token);

      // Visit authenticated page
      cy.visit('https://example.com/dashboard');

      // Execute test
      cy.get('selector').should('be.visible');
    });
  });
});

These methods ensure that test cases dependent on specific cookies are executed only after the relevant cookies have been correctly set and synchronized.