Testing external redirects in Cypress.io

cypress-integration-redirects.spec.js

it('should go to external page after clicking on CTA button', () => { // it's not click per se - we use element's href attribute
  cy.get('a[href*="redirect"]') //finds all redirect links
    .each(($linkElement) => {
      const internalUrl = $linkElement.attr('href');

      cy.log(`Checking redirect for ${internalUrl}`);

      cy.getExternalRedirect(internalUrl) // gets 302 redirect
        .as('externalRedirect'); // saves the request as alias for the assertions

      cy.get('@externalRedirect')
        .its('status') // extract status property from request
        .should('be.equal', 302); // check if status set to 302

      cy.get('@externalRedirect')
        .its('redirectedToUrl') // extract redirect url property from request
        .should('not.be.empty'); // check if not empty
    });
});

cypress-support-commands.js

Cypress.Commands.add('getExternalRedirect', (internalRedirectUrl) => {
  cy.request(internalRedirectUrl).then((response) => {
    const { body } = response;
    const externalRedirectUrlParts = body.match(/\d+;URL=(.*)"/); // extract redirect url from meta[http-equiv="refresh"]
    expect(externalRedirectUrlParts).not.to.be.null;

    const externalRedirectUrl = externalRedirectUrlParts[1];
    expect(externalRedirectUrl).to.be.defined;

    cy.request({
      url: externalRedirectUrl,
      followRedirect: false // don't go to external page
    }).then((redirectResponse) => {
      const { status, headers } = redirectResponse;
      const isInternalRedirect = status !== 302 && headers.location.includes(window.location.host);

      if (isInternalRedirect) { // we're still on our page, dig deeper
        cy.request({
          url: headers.location,
          followRedirect: false // don't go to external page
        })
      } else {
        cy.wrap(redirectResponse);
      }
    });
  });
});