Fix Generate API schema name mismatch (#9651)

* Match serializer (and schema) to API-returned json data

* Bump schema version

src/backend/InvenTree/InvenTree/api_version.py

@@ -1,12 +1,15 @@
 """InvenTree API version information."""
 
 # InvenTree API version
-INVENTREE_API_VERSION = 341
+INVENTREE_API_VERSION = 342
 
 """Increment this API version number whenever there is a significant change to the API that any clients need to know about."""
 
 
 INVENTREE_API_TEXT = """
+v342 -> 2025-05-09 : https://github.com/inventree/InvenTree/pull/9651
+    - Fix serializer to match Generate API for serial numbers
+
 v341 -> 2025-04-21 : https://github.com/inventree/InvenTree/pull/9547
     - Require pagination limit on list queries
 

src/backend/InvenTree/stock/serializers.py

@@ -143,20 +143,24 @@ class GenerateSerialNumberSerializer(serializers.Serializer):
     Any of the provided write-only fields can be used for additional context.
 
     Note that in the case where multiple serial numbers are required,
-    the "serial" field will return a string with multiple serial numbers separated by a comma.
+    the "serial_number" field will return a string with multiple serial numbers
+    separated by a comma.
     """
 
     class Meta:
         """Metaclass options."""
 
-        fields = ['serial', 'part', 'quantity']
+        fields = ['serial_number', 'part', 'quantity']
 
-        read_only_fields = ['serial']
+        read_only_fields = ['serial_number']
 
         write_only_fields = ['part', 'quantity']
 
-    serial = serializers.CharField(
-        read_only=True, help_text=_('Generated serial number'), label=_('Serial Number')
+    serial_number = serializers.CharField(
+        read_only=True,
+        allow_null=True,
+        help_text=_('Generated serial number'),
+        label=_('Serial Number'),
     )
 
     part = serializers.PrimaryKeyRelatedField(