fix: handle results that can't be mapped to the changeset in bulk_create

If the identity used has attibutes that can be generated by the
datalayer, we can't map the result back to the changeset and we need to
just zip the results with the changesets and return them that way.

Author: barnabasJ

lib/data_layer.ex

@@ -2123,35 +2123,63 @@ defmodule AshPostgres.DataLayer do
                 {Map.take(r, keys), r}
               end)
 
-            results =
-              changesets
-              |> Enum.map(fn changeset ->
-                identity =
-                  changeset.attributes
-                  |> Map.take(keys)
+            cant_map_results_to_changesets =
+              any_generated_keys_missing?(keys, resource, changesets)
 
-                result_for_changeset = Map.get(results_by_identity, identity)
-
-                if result_for_changeset do
+            results =
+              if cant_map_results_to_changesets do
+                results
+                |> Enum.zip(changesets)
+                |> Enum.map(fn {result, changeset} ->
                   if !opts[:upsert?] do
-                    maybe_create_tenant!(resource, result_for_changeset)
+                    maybe_create_tenant!(resource, result)
                   end
 
                   case get_bulk_operation_metadata(changeset) do
                     {index, metadata_key} ->
-                      Ash.Resource.put_metadata(result_for_changeset, metadata_key, index)
+                      Ash.Resource.put_metadata(result, metadata_key, index)
 
                     nil ->
                       # Compatibility fallback
                       Ash.Resource.put_metadata(
-                        result_for_changeset,
+                        result,
                         :bulk_create_index,
                         changeset.context[:bulk_create][:index]
                       )
                   end
-                end
-              end)
-              |> Enum.filter(& &1)
+                end)
+              else
+                changesets
+                |> Enum.map(fn changeset ->
+                  identity =
+                    changeset.attributes
+                    |> Map.take(keys)
+
+                  result_for_changeset = Map.get(results_by_identity, identity)
+
+                  if result_for_changeset do
+                    if !opts[:upsert?] do
+                      maybe_create_tenant!(resource, result_for_changeset)
+                    end
+
+                    case get_bulk_operation_metadata(changeset) do
+                      {index, metadata_key} ->
+                        Ash.Resource.put_metadata(result_for_changeset, metadata_key, index)
+
+                      nil ->
+                        # Compatibility fallback
+                        Ash.Resource.put_metadata(
+                          result_for_changeset,
+                          :bulk_create_index,
+                          changeset.context[:bulk_create][:index]
+                        )
+                    end
+                  end
+                end)
+                |> Enum.concat(results)
+                |> Enum.filter(& &1)
+                |> Enum.uniq_by(&Map.take(&1, keys))
+              end
 
             {:ok, results}
           end
@@ -3737,6 +3765,16 @@ defmodule AshPostgres.DataLayer do
     end
   end
 
+  # checks if any of the attributes in the list of keys are generated and missing from any of the changesets
+  # if so, we can't match the created record to the changeset by the identity and just need to zip the return
+  # values with the changesets
+  defp any_generated_keys_missing?(keys, resource, changesets) do
+    Enum.any?(keys, fn key ->
+      Ash.Resource.Info.attribute(resource, key).generated? &&
+        Enum.any?(changesets, fn changeset -> is_nil(changeset.attributes[key]) end)
+    end)
+  end
+
   defp get_bulk_operation_metadata(changeset) do
     changeset.context
     |> Enum.find_value(fn

test/bulk_create_test.exs

@@ -4,7 +4,7 @@
 
 defmodule AshPostgres.BulkCreateTest do
   use AshPostgres.RepoCase, async: false
-  alias AshPostgres.Test.{Post, Record}
+  alias AshPostgres.Test.{IntegerPost, Post, Record}
 
   require Ash.Query
   import Ash.Expr
@@ -356,6 +356,18 @@ defmodule AshPostgres.BulkCreateTest do
                |> Ash.Query.load(:ratings)
                |> Ash.read!()
     end
+
+    test "bulk creates with integer primary key return records" do
+      %Ash.BulkResult{records: records} =
+        Ash.bulk_create!(
+          [%{title: "first"}, %{title: "second"}, %{title: "third"}],
+          IntegerPost,
+          :create,
+          return_records?: true
+        )
+
+      assert length(records) == 3
+    end
   end
 
   describe "validation errors" do