From de0bd815e8cb3ad168ebef777bd62ec7e5fde17c Mon Sep 17 00:00:00 2001
From: Barnabas Jovanovics <barnabas.jovanovics@gmail.com>
Date: Mon, 13 May 2024 18:45:31 +0200
Subject: [PATCH] fix: add __source__ to union inner_constraints (#1160)

---
 lib/ash/type/union.ex | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/lib/ash/type/union.ex b/lib/ash/type/union.ex
index ab22de1c..b5c18c9b 100644
--- a/lib/ash/type/union.ex
+++ b/lib/ash/type/union.ex
@@ -365,7 +365,14 @@ defmodule Ash.Type.Union do
 
     inner_constraints =
       if Ash.Type.embedded_type?(type) do
-        Keyword.put(inner_constraints, :__union_tag__, constraints[:types][type_name][:tag])
+        case constraints[:__source__] do
+          %Ash.Changeset{} = source ->
+            Keyword.put(inner_constraints, :__source__, source)
+
+          _ ->
+            inner_constraints
+        end
+        |> Keyword.put(:__union_tag__, constraints[:types][type_name][:tag])
       else
         inner_constraints
       end