fix: field appending on duplicate should ignore non string values (#11621)

### What?
When duplicating a document with `unique` fields, we append `- Copy` to
the field value.
The issue is that this is happening when the field is empty resulting in
values being added that look like: `undefined - Copy` or `null - Copy`.

### Why?
We are not checking the incoming value in all cases.

### How?
Checks the value exists, is a string, and is not just an empty space
before appending `- Copy`.

At first glance it looks incorrect to return required fields with
`undefined` - however when duplicating a document, the new document is
always created as a `draft` so it is not an issue to return `undefined`.

Closes #11373

packages/payload/src/fields/setDefaultBeforeDuplicate.ts

@@ -2,12 +2,10 @@
 // default beforeDuplicate hook for required and unique fields
 import { type FieldAffectingData, type FieldHook, fieldShouldBeLocalized } from './config/types.js'
 
-const unique: FieldHook = ({ value }) => (typeof value === 'string' ? `${value} - Copy` : undefined)
+const isStringValue = (value) => typeof value === 'string' && value.trim() !== ''
+const unique: FieldHook = ({ value }) => (isStringValue(value) ? `${value} - Copy` : undefined)
 const localizedUnique: FieldHook = ({ req, value }) =>
-  value ? `${value} - ${req?.t('general:copy') ?? 'Copy'}` : undefined
-const uniqueRequired: FieldHook = ({ value }) => `${value} - Copy`
-const localizedUniqueRequired: FieldHook = ({ req, value }) =>
-  `${value} - ${req?.t('general:copy') ?? 'Copy'}`
+  isStringValue(value) ? `${value} - ${req?.t('general:copy') ?? 'Copy'}` : undefined
 
 export const setDefaultBeforeDuplicate = (
   field: FieldAffectingData,
@@ -18,16 +16,14 @@ export const setDefaultBeforeDuplicate = (
     (!field.hooks?.beforeDuplicate ||
       (Array.isArray(field.hooks.beforeDuplicate) && field.hooks.beforeDuplicate.length === 0))
   ) {
-    if ((field.type === 'text' || field.type === 'textarea') && field.required && field.unique) {
-      field.hooks.beforeDuplicate = [
-        fieldShouldBeLocalized({ field, parentIsLocalized })
-          ? localizedUniqueRequired
-          : uniqueRequired,
-      ]
-    } else if (field.unique) {
-      field.hooks.beforeDuplicate = [
-        fieldShouldBeLocalized({ field, parentIsLocalized }) ? localizedUnique : unique,
-      ]
+    if (field.unique) {
+      if (['email', 'number', 'point', 'relationship', 'select', 'upload'].includes(field.type)) {
+        field.hooks.beforeDuplicate = [() => undefined]
+      } else if (['code', 'json', 'text', 'textarea'].includes(field.type)) {
+        field.hooks.beforeDuplicate = fieldShouldBeLocalized({ field, parentIsLocalized })
+          ? [localizedUnique]
+          : [unique]
+      }
     }
   }
 }