feat(gopay): support GoPay Plus checkout flow

gopay-utils.js

@@ -0,0 +1,56 @@
+(function attachGoPayUtils(root, factory) {
+  root.GoPayUtils = factory();
+})(typeof self !== 'undefined' ? self : globalThis, function createGoPayUtils() {
+  const PLUS_PAYMENT_METHOD_PAYPAL = 'paypal';
+  const PLUS_PAYMENT_METHOD_GOPAY = 'gopay';
+
+  function normalizePlusPaymentMethod(value = '') {
+    return String(value || '').trim().toLowerCase() === PLUS_PAYMENT_METHOD_GOPAY
+      ? PLUS_PAYMENT_METHOD_GOPAY
+      : PLUS_PAYMENT_METHOD_PAYPAL;
+  }
+
+  const DEFAULT_GOPAY_COUNTRY_CODE = '+86';
+
+  function normalizeGoPayCountryCode(value = '') {
+    const normalized = String(value || '').trim().replace(/[^\d+]/g, '');
+    const digits = normalized.replace(/\D/g, '');
+    return digits ? `+${digits}` : DEFAULT_GOPAY_COUNTRY_CODE;
+  }
+
+  function normalizeGoPayPhone(value = '') {
+    return String(value || '').trim().replace(/[^\d+]/g, '');
+  }
+
+  function normalizeGoPayPhoneForCountry(value = '', countryCode = DEFAULT_GOPAY_COUNTRY_CODE) {
+    const normalizedPhone = normalizeGoPayPhone(value);
+    const normalizedCountryCode = normalizeGoPayCountryCode(countryCode);
+    const countryDigits = normalizedCountryCode.replace(/\D/g, '');
+    let nationalNumber = normalizedPhone.replace(/\D/g, '');
+
+    if (countryDigits && nationalNumber.startsWith(countryDigits)) {
+      nationalNumber = nationalNumber.slice(countryDigits.length);
+    }
+    return nationalNumber;
+  }
+
+  function normalizeGoPayPin(value = '') {
+    return String(value || '').trim().replace(/[^\d]/g, '');
+  }
+
+  function normalizeGoPayOtp(value = '') {
+    return String(value || '').trim().replace(/[^\d]/g, '');
+  }
+
+  return {
+    DEFAULT_GOPAY_COUNTRY_CODE,
+    PLUS_PAYMENT_METHOD_GOPAY,
+    PLUS_PAYMENT_METHOD_PAYPAL,
+    normalizeGoPayCountryCode,
+    normalizeGoPayPhone,
+    normalizeGoPayPhoneForCountry,
+    normalizeGoPayOtp,
+    normalizeGoPayPin,
+    normalizePlusPaymentMethod,
+  };
+});