commands.js

/**
 * Fetch the body of an iFrame.
 */
Cypress.Commands.add('getIframe', () => {
    return cy
        .get('iframe')
        .its('0.contentDocument.body', { log: false })
        .should('not.be.empty')
        .then((body) => {
            cy.wrap(body, { log: false });
        });
});

/**
 * Enter the card details for a Stripe elements form.
 *
 * @param  {Object} options
 */
Cypress.Commands.add('enterStripeCard', (options = {}) => {
    options = {
        ...{ approved: true },
        ...options,
    };

    cy.getIframe().within(() => {
        cy.get('[name=cardnumber]')
            .type(options.approved ? '4242424242424242' : '4000000000000002')
            .wait(300);

        cy.get('[name=exp-date]').type('0424').wait(300);
        cy.get('[name=cvc]').type('242').wait(300);
        cy.get('[name=postal]').type('42424');
    });
});