woocommerce-paypal-payments/modules/ppcp-googlepay/resources/js/Context/CheckoutHandler.js

import Spinner from "../../../../ppcp-button/resources/js/modules/Helper/Spinner";
import BaseHandler from "./BaseHandler";
import CheckoutActionHandler
    from "../../../../ppcp-button/resources/js/modules/ActionHandler/CheckoutActionHandler";
import FormValidator from "../../../../ppcp-button/resources/js/modules/Helper/FormValidator";

class CheckoutHandler extends BaseHandler {

    shippingAllowed() {
        return false;
    }

    transactionInfo() {
        return new Promise(async (resolve, reject) => {

            try {
                const spinner = new Spinner();
                const errorHandler = this.errorHandler();

                const formSelector = this.ppcpConfig.context === 'checkout' ? 'form.checkout' : 'form#order_review';
                const formValidator = this.ppcpConfig.early_checkout_validation_enabled ?
                    new FormValidator(
                        this.ppcpConfig.ajax.validate_checkout.endpoint,
                        this.ppcpConfig.ajax.validate_checkout.nonce,
                    ) : null;

                if (!formValidator) {
                    resolve(super.transactionInfo());
                    return;
                }

                formValidator.validate(document.querySelector(formSelector)).then((errors) => {
                    if (errors.length > 0) {
                        spinner.unblock();
                        errorHandler.clear();
                        errorHandler.messages(errors);

                        // fire WC event for other plugins
                        jQuery( document.body ).trigger( 'checkout_error' , [ errorHandler.currentHtml() ] );

                        reject();
                    } else {
                        resolve(super.transactionInfo());
                    }
                });

            } catch (error) {
                console.error(error);
                reject();
            }
        });
    }

    actionHandler() {
        return new CheckoutActionHandler(
            this.ppcpConfig,
            this.errorHandler(),
            new Spinner()
        );
    }

}

export default CheckoutHandler;