Extract method

Author: Bart Koelman

src/JsonApiDotNetCore/Services/JsonApiResourceService.cs

@@ -226,17 +226,7 @@ private async Task RetrieveResourceCountForNonPrimaryEndpointAsync(TId id, HasMa
             }
             catch (DataStoreUpdateException)
             {
-                if (!Equals(resourceFromRequest.Id, default(TId)))
-                {
-                    TResource? existingResource =
-                        await GetPrimaryResourceByIdOrDefaultAsync(resourceFromRequest.Id, TopFieldSelection.OnlyIdAttribute, cancellationToken);
-
-                    if (existingResource != null)
-                    {
-                        throw new ResourceAlreadyExistsException(resourceFromRequest.StringId!, _request.PrimaryResourceType.PublicName);
-                    }
-                }
-
+                await AssertPrimaryResourceDoesNotExistAsync(resourceFromRequest, cancellationToken);
                 await AssertResourcesToAssignInRelationshipsExistAsync(resourceFromRequest, cancellationToken);
                 throw;
             }
@@ -249,6 +239,19 @@ private async Task RetrieveResourceCountForNonPrimaryEndpointAsync(TId id, HasMa
             return hasImplicitChanges ? resourceFromDatabase : null;
         }
 
+        protected async Task AssertPrimaryResourceDoesNotExistAsync(TResource resource, CancellationToken cancellationToken)
+        {
+            if (!Equals(resource.Id, default(TId)))
+            {
+                TResource? existingResource = await GetPrimaryResourceByIdOrDefaultAsync(resource.Id, TopFieldSelection.OnlyIdAttribute, cancellationToken);
+
+                if (existingResource != null)
+                {
+                    throw new ResourceAlreadyExistsException(resource.StringId!, _request.PrimaryResourceType!.PublicName);
+                }
+            }
+        }
+
         protected virtual async Task InitializeResourceAsync(TResource resourceForDatabase, CancellationToken cancellationToken)
         {
             await _resourceDefinitionAccessor.OnPrepareWriteAsync(resourceForDatabase, WriteOperationKind.CreateResource, cancellationToken);