Resolve Rule coupon code generate form validation issue23778

Author: edenduong

app/code/Magento/SalesRule/view/adminhtml/templates/promo/salesrulejs.phtml

@@ -20,10 +20,19 @@ function refreshCouponCodesGrid(grid, gridMassAction, transport) {
 
 function generateCouponCodes(idPrefix, generateUrl, grid) {
     $(idPrefix + 'information_fieldset').removeClassName('ignore-validate');
+    var listInvalidElement = [];
     var validationResult = $(idPrefix + 'information_fieldset').select('input',
             'select', 'textarea').collect( function(elm) {
-        return jQuery.validator.validateElement(elm);
+        var validateOneElementResult = jQuery.validator.validateSingleElement(elm);
+        if (!validateOneElementResult) {
+            listInvalidElement.push(elm);
+        }
+        return validateOneElementResult;
     }).all();
+    if (listInvalidElement.length) {
+        listInvalidElement[0].focus();
+    }
+
     $(idPrefix + 'information_fieldset').addClassName('ignore-validate');
 
     if (!validationResult) {