Fix ticket quantity buttons on event page - Remove syntax error in ticket card component and improve error handling in ticket cart controller

app/javascript/controllers/ticket_cart_controller.js

@@ -16,6 +16,11 @@ export default class extends Controller {
     const ticketTypeId = event.params.ticketTypeId
     const max = parseInt(event.params.max)
     const input = this.quantityTargetFor(ticketTypeId)
+    
+    if (!input) {
+      console.error(`Could not find input for ticket type ID: ${ticketTypeId}`)
+      return
+    }
 
     const current = parseInt(input.value) || 0
     if (current < max) {
@@ -27,6 +32,11 @@ export default class extends Controller {
   decreaseQuantity(event) {
     const ticketTypeId = event.params.ticketTypeId
     const input = this.quantityTargetFor(ticketTypeId)
+    
+    if (!input) {
+      console.error(`Could not find input for ticket type ID: ${ticketTypeId}`)
+      return
+    }
 
     const current = parseInt(input.value) || 0
     if (current > 0) {
@@ -38,6 +48,12 @@ export default class extends Controller {
   updateQuantityFromInput(event) {
     const input = event.target
     const ticketTypeId = input.dataset.ticketTypeId
+    
+    if (!ticketTypeId) {
+      console.error('Missing ticket type ID on input element')
+      return
+    }
+    
     const max = parseInt(input.max)
     const quantity = parseInt(input.value) || 0
 
@@ -308,6 +324,10 @@ export default class extends Controller {
 
   // Helper method to find quantity input by ticket type ID
   quantityTargetFor(ticketTypeId) {
-    return document.querySelector(`#quantity_${ticketTypeId}`)
+    const element = document.querySelector(`#quantity_${ticketTypeId}`)
+    if (!element) {
+      console.warn(`Could not find quantity input for ticket type ID: ${ticketTypeId}`)
+    }
+    return element
   }
 }