Add validation error to prevent checkout when there is no shipping method available

assets/js/base/context/providers/cart-checkout/checkout-processor.ts

@@ -14,7 +14,7 @@ import {
 	emptyHiddenAddressFields,
 	removeAllNotices,
 } from '@woocommerce/base-utils';
-import { useDispatch, useSelect } from '@wordpress/data';
+import { useDispatch, useSelect, select as selectStore } from '@wordpress/data';
 import {
 	CHECKOUT_STORE_KEY,
 	PAYMENT_STORE_KEY,
@@ -160,6 +160,19 @@ const CheckoutProcessor = () => {
 
 	const checkValidation = useCallback( () => {
 		if ( hasValidationErrors() ) {
+			// If there is a shipping rates validation error, return the error message to be displayed.
+			if (
+				selectStore( VALIDATION_STORE_KEY ).getValidationError(
+					'shipping-rates-error'
+				) !== undefined
+			) {
+				return {
+					errorMessage: __(
+						'Sorry, this order requires a shipping option.',
+						'woo-gutenberg-products-block'
+					),
+				};
+			}
 			return false;
 		}
 		if ( hasPaymentError ) {

assets/js/blocks/checkout/inner-blocks/checkout-shipping-method-block/block.tsx

@@ -9,6 +9,9 @@ import {
 } from 'wordpress-components';
 import classnames from 'classnames';
 import { Icon, store, shipping } from '@wordpress/icons';
+import { useEffect } from '@wordpress/element';
+import { VALIDATION_STORE_KEY } from '@woocommerce/block-data';
+import { useDispatch } from '@wordpress/data';
 
 /**
  * Internal dependencies
@@ -19,6 +22,14 @@ import type { minMaxPrices } from './shared';
 import { defaultLocalPickupText, defaultShippingText } from './constants';
 import { shippingAddressHasValidationErrors } from '../../../../data/cart/utils';
 
+const SHIPPING_RATE_ERROR = {
+	hidden: true,
+	message: __(
+		'Shipping options are not available',
+		'woo-gutenberg-products-block'
+	),
+};
+
 const LocalPickupSelector = ( {
 	checked,
 	rate,
@@ -83,6 +94,23 @@ const ShippingSelector = ( {
 } ) => {
 	const rateShouldBeHidden =
 		shippingCostRequiresAddress && shippingAddressHasValidationErrors();
+	const hasShippingPrices = rate.min !== undefined && rate.max !== undefined;
+	const { setValidationErrors, clearValidationError } =
+		useDispatch( VALIDATION_STORE_KEY );
+	useEffect( () => {
+		if ( checked === 'shipping' && ! hasShippingPrices ) {
+			setValidationErrors( {
+				'shipping-rates-error': SHIPPING_RATE_ERROR,
+			} );
+		} else {
+			clearValidationError( 'shipping-rates-error' );
+		}
+	}, [
+		checked,
+		clearValidationError,
+		hasShippingPrices,
+		setValidationErrors,
+	] );
 	const Price =
 		rate.min === undefined || rateShouldBeHidden ? (
 			<span className="wc-block-checkout__shipping-method-option-price">

assets/js/blocks/checkout/inner-blocks/checkout-shipping-method-block/shared/rate-price.tsx

@@ -16,7 +16,7 @@ export const RatePrice = ( {
 }: {
 	minRate: CartShippingPackageShippingRate | undefined;
 	maxRate: CartShippingPackageShippingRate | undefined;
-	multiple: boolean;
+	multiple?: boolean;
 } ) => {
 	if ( minRate === undefined || maxRate === undefined ) {
 		return null;