DefinitelyTyped/types/stripe/stripe-tests.ts

function success(card: StripeCard) {
    console.log(card.brand && card.brand.toString());
}

const cardNumber = '4242424242424242';

const isValid = Stripe.validateCardNumber(cardNumber);
if (isValid) {
    const tokenData: StripeCardTokenData = {
        number: cardNumber,
        exp_month: 1,
        exp_year: 2100,
        cvc: '111'
    };
    Stripe.card.createToken(tokenData, (status, response) => {
        if (response.error) {
            console.error(response.error.message);
            if (response.error.param) {
                console.error(response.error.param);
            }
        } else {
            success(response.card);
        }
    });
}