Fix Uncaught TypeError: Cannot read property 'length' of undefined

Author: wvega

woocommerce/changelog.txt

@@ -3,6 +3,7 @@
 2020.01.20 - version 5.5.4
  * Tweak - Add a link to the site's terms and conditions page below Apple Pay buttons when available
  * Tweak - Adjust the place order button label for redirect/hosted gateways
+ * Fix - Fix a JavaScript error triggered trying read the 'length' property of an undefined value in format_credit_card_inputs()
 
 2020.01.13 - version 5.5.3
  * Fix - Fix a JavaScript error when instantiating a class that hasn't been loaded

woocommerce/payment-gateway/assets/js/frontend/sv-wc-payment-gateway-payment-form.coffee

@@ -155,9 +155,9 @@ jQuery( document ).ready ($) ->
 			$csc         = $('.js-sv-wc-payment-gateway-credit-card-form-csc').payment('formatCardCVC');
 
 			# trigger a 'change' event for non empty fields only
-			$card_number.trigger( 'change') if $card_number.val().length > 0
-			$expiry.trigger( 'change') if $expiry.val().length > 0
-			$csc.trigger( 'change') if $csc.val().length > 0
+			$card_number.trigger( 'change') if $card_number.val() && $card_number.val().length > 0
+			$expiry.trigger( 'change') if $expiry.val() && $expiry.val().length > 0
+			$csc.trigger( 'change') if $csc.val() && $csc.val().length > 0
 
 			# perform inline validation on credit card inputs
 			$( '.js-sv-wc-payment-gateway-credit-card-form-input' ).on( 'change paste keyup', => this.do_inline_credit_card_validation() )