In Cypress, set a token in localStorage before test

In Cypress, to set a token in localStorage before executing test cases, you can use the cy commands. This is typically implemented within the beforeEach hook to ensure the necessary state is set prior to each test execution. Here is an example:

javascript
describe('Token Setting in LocalStorage', () => {
  beforeEach(() => {
    cy.visit('/'); // Navigate to the initial application page

    // Set the token in localStorage
    cy.window().then((win) => {
      win.localStorage.setItem('token', 'yourTokenValue');
    });
  });

  // Write test cases here
  it('should have token set in localStorage', () => {
    // Verify the token is correctly set in localStorage
    cy.window().should((win) => {
      expect(win.localStorage.getItem('token')).to.eq('yourTokenValue');
    });
  });
});

In this example, we first invoke cy.visit('/') to load the application's initial page. Then, within the beforeEach hook, we access the browser window object using cy.window() and utilize its localStorage.setItem method to set the token. 'yourTokenValue' should be replaced with the actual token value.

Subsequently, each test case within an it block executes in an environment where the token is present in localStorage. Within the test cases, you can use expect statements to confirm that the token in localStorage is properly set, aiding in verifying the success of the setup.

Note that in certain scenarios, you may need to wait for asynchronous operations to complete before setting localStorage, or your application might clear localStorage during initialization. In these cases, ensure that localStorage is set after the application's initialization logic has finished. This can be done by setting localStorage within the callback of cy.visit('/').then(() => { /* set localStorage here */ }) to guarantee proper sequencing.