Order creation fix (#8846)

* Bug fix for PurchaseOrder

- Correctly record the user who created a PO
- Code refactoring

* Updated unit tests

src/backend/InvenTree/order/api.py

@@ -75,6 +75,24 @@ class GeneralExtraLineList(DataExportViewMixin):
     filterset_fields = ['order']
 
 
+class OrderCreateMixin:
+    """Mixin class which handles order creation via API."""
+
+    def create(self, request, *args, **kwargs):
+        """Save user information on order creation."""
+        serializer = self.get_serializer(data=self.clean_data(request.data))
+        serializer.is_valid(raise_exception=True)
+
+        item = serializer.save()
+        item.created_by = request.user
+        item.save()
+
+        headers = self.get_success_headers(serializer.data)
+        return Response(
+            serializer.data, status=status.HTTP_201_CREATED, headers=headers
+        )
+
+
 class OrderFilter(rest_filters.FilterSet):
     """Base class for custom API filters for the OrderList endpoint."""
 
@@ -266,7 +284,9 @@ class PurchaseOrderMixin:
         return queryset
 
 
-class PurchaseOrderList(PurchaseOrderMixin, DataExportViewMixin, ListCreateAPI):
+class PurchaseOrderList(
+    PurchaseOrderMixin, OrderCreateMixin, DataExportViewMixin, ListCreateAPI
+):
     """API endpoint for accessing a list of PurchaseOrder objects.
 
     - GET: Return list of PurchaseOrder objects (with filters)
@@ -728,7 +748,9 @@ class SalesOrderMixin:
         return queryset
 
 
-class SalesOrderList(SalesOrderMixin, DataExportViewMixin, ListCreateAPI):
+class SalesOrderList(
+    SalesOrderMixin, OrderCreateMixin, DataExportViewMixin, ListCreateAPI
+):
     """API endpoint for accessing a list of SalesOrder objects.
 
     - GET: Return list of SalesOrder objects (with filters)
@@ -737,20 +759,6 @@ class SalesOrderList(SalesOrderMixin, DataExportViewMixin, ListCreateAPI):
 
     filterset_class = SalesOrderFilter
 
-    def create(self, request, *args, **kwargs):
-        """Save user information on create."""
-        serializer = self.get_serializer(data=self.clean_data(request.data))
-        serializer.is_valid(raise_exception=True)
-
-        item = serializer.save()
-        item.created_by = request.user
-        item.save()
-
-        headers = self.get_success_headers(serializer.data)
-        return Response(
-            serializer.data, status=status.HTTP_201_CREATED, headers=headers
-        )
-
     def filter_queryset(self, queryset):
         """Perform custom filtering operations on the SalesOrder queryset."""
         queryset = super().filter_queryset(queryset)
@@ -1345,25 +1353,13 @@ class ReturnOrderMixin:
         return queryset
 
 
-class ReturnOrderList(ReturnOrderMixin, DataExportViewMixin, ListCreateAPI):
+class ReturnOrderList(
+    ReturnOrderMixin, OrderCreateMixin, DataExportViewMixin, ListCreateAPI
+):
     """API endpoint for accessing a list of ReturnOrder objects."""
 
     filterset_class = ReturnOrderFilter
 
-    def create(self, request, *args, **kwargs):
-        """Save user information on create."""
-        serializer = self.get_serializer(data=self.clean_data(request.data))
-        serializer.is_valid(raise_exception=True)
-
-        item = serializer.save()
-        item.created_by = request.user
-        item.save()
-
-        headers = self.get_success_headers(serializer.data)
-        return Response(
-            serializer.data, status=status.HTTP_201_CREATED, headers=headers
-        )
-
     filter_backends = SEARCH_ORDER_FILTER_ALIAS
 
     ordering_field_aliases = {

src/backend/InvenTree/order/test_api.py

@@ -255,7 +255,10 @@ class PurchaseOrderTest(OrderTest):
 
         order = models.PurchaseOrder.objects.get(pk=response.data['pk'])
 
-        self.assertEqual(order.reference, 'PO-92233720368547758089999999999999999')
+        # Check that the created_by field is set correctly
+        self.assertEqual(order.created_by.username, 'testuser')
+
+        self.assertEqual(order.reference, huge_number)
         self.assertEqual(order.reference_int, 0x7FFFFFFF)
 
     def test_po_reference_wildcard_default(self):
@@ -1407,6 +1410,11 @@ class SalesOrderTest(OrderTest):
         # Grab the PK for the newly created SalesOrder
         pk = response.data['pk']
 
+        # Basic checks against the newly created SalesOrder
+        so = models.SalesOrder.objects.get(pk=pk)
+        self.assertEqual(so.reference, 'SO-12345')
+        self.assertEqual(so.created_by.username, 'testuser')
+
         # Try to create a SO with identical reference (should fail)
         response = self.post(
             url,