fix: pricing decimal formatting for tokenized cart (#8998)

Co-authored-by: Timur Karimov <timur.karimow.95@gmail.com>

changelog/fix-tokenized-cart-zero-decimal-currency

@@ -0,0 +1,5 @@
+Significance: patch
+Type: fix
+Comment: fix: tokenized PRB with zero decimal currency
+
+

client/tokenized-payment-request/transformers/__tests__/wc-to-stripe.test.js

@@ -0,0 +1,54 @@
+/**
+ * Internal dependencies
+ */
+import { transformPrice } from '../wc-to-stripe';
+
+global.wcpayPaymentRequestParams = {};
+global.wcpayPaymentRequestParams.checkout = {};
+
+describe( 'wc-to-stripe transformers', () => {
+	describe( 'transformPrice', () => {
+		afterEach( () => {
+			delete global.wcpayPaymentRequestParams.checkout.currency_decimals;
+		} );
+
+		it( 'transforms the price', () => {
+			expect( transformPrice( 180, { currency_minor_unit: 2 } ) ).toBe(
+				180
+			);
+		} );
+
+		it( 'transforms the price if the currency is configured with one decimal', () => {
+			// with one decimal, `180` would mean `18.0`.
+			// But since Stripe expects the price to be in cents, the return value should be `1800`
+			expect( transformPrice( 180, { currency_minor_unit: 1 } ) ).toBe(
+				1800
+			);
+		} );
+
+		it( 'transforms the price if the currency is configured with two decimals', () => {
+			// with two decimals, `1800` would mean `18.00`.
+			// But since Stripe expects the price to be in cents, the return value should be `1800`
+			expect( transformPrice( 1800, { currency_minor_unit: 2 } ) ).toBe(
+				1800
+			);
+		} );
+
+		it( 'transforms the price if the currency is a zero decimal currency (e.g.: Yen)', () => {
+			global.wcpayPaymentRequestParams.checkout.currency_decimals = 0;
+			// with zero decimals, `18` would mean `18`.
+			expect( transformPrice( 18, { currency_minor_unit: 0 } ) ).toBe(
+				18
+			);
+		} );
+
+		it( 'transforms the price if the currency a zero decimal currency (e.g.: Yen) but it is configured with one decimal', () => {
+			global.wcpayPaymentRequestParams.checkout.currency_decimals = 0;
+			// with zero decimals, `18` would mean `18`.
+			// But since Stripe expects the price to be in the minimum currency amount, the return value should be `18`
+			expect( transformPrice( 180, { currency_minor_unit: 1 } ) ).toBe(
+				18
+			);
+		} );
+	} );
+} );

client/tokenized-payment-request/transformers/wc-to-stripe.js

@@ -3,6 +3,11 @@
  */
 import { __ } from '@wordpress/i18n';
 
+/**
+ * Internal dependencies
+ */
+import { getPaymentRequestData } from '../frontend-utils';
+
 /**
  * GooglePay/ApplePay expect the prices to be formatted in cents.
  * But WooCommerce has a setting to define the number of decimals for amounts.
@@ -14,9 +19,13 @@ import { __ } from '@wordpress/i18n';
  *
  * @return {number} the price amount for GooglePay/ApplePay, always expressed in cents.
  */
-export const transformPrice = ( price, priceObject ) =>
+export const transformPrice = ( price, priceObject ) => {
+	const currencyDecimals =
+		getPaymentRequestData( 'checkout' )?.currency_decimals ?? 2;
+
 	// making sure the decimals are always correctly represented for GooglePay/ApplePay, since they don't allow us to specify the decimals.
-	price * 10 ** ( 2 - priceObject.currency_minor_unit );
+	return price * 10 ** ( currencyDecimals - priceObject.currency_minor_unit );
+};
 
 /**
  * Transforms the data from the Store API Cart response to `displayItems` for the Stripe PRB.

includes/class-wc-payments-payment-request-button-handler.php

@@ -970,6 +970,7 @@ public function scripts() {
 			],
 			'checkout'           => [
 				'currency_code'     => strtolower( get_woocommerce_currency() ),
+				'currency_decimals' => WC_Payments::get_localization_service()->get_currency_format( get_woocommerce_currency() )['num_decimals'],
 				'country_code'      => substr( get_option( 'woocommerce_default_country' ), 0, 2 ),
 				'needs_shipping'    => WC()->cart->needs_shipping(),
 				// Defaults to 'required' to match how core initializes this option.