Ticket #34257: raw_fk_widget_missing_class.patch

django/contrib/admin/widgets.py

@@ -157 +157 @@
             css_class = "vForeignKeyRawIdAdminField"
             if isinstance(self.rel.get_related_field(), UUIDField):
                 css_class += " vUUIDField"
-            context["widget"]["attrs"].setdefault("class", css_class)
+            if "class" in context["widget"]["attrs"]:
+                context["widget"]["attrs"]["class"] += f" {css_class}"
+            else:
+                context["widget"]["attrs"]["class"] = css_class
         else:
             context["related_url"] = None
         if context["widget"]["value"]:

tests/admin_widgets/tests.py

@@ -757 +757 @@
             'class="related-lookup" id="lookup_id_test" title="Lookup"></a>',
         )
 
+    def test_includes_class_override(self):
+        rel = ReleaseEvent._meta.get_field("album").remote_field
+        attrs = {"class": "myClass"}
+        w = widgets.ForeignKeyRawIdWidget(rel, widget_admin_site, attrs=attrs)
+        self.assertHTMLEqual(
+            w.render("test", None),
+            '<input type="text" name="test" class="myClass vForeignKeyRawIdAdminField">'
+            '<a href="/admin_widgets/album/?_to_field=id" class="related-lookup" '
+            'id="lookup_id_test" title="Lookup"></a>',
+        )
+
 
 @override_settings(ROOT_URLCONF="admin_widgets.urls")
 class ManyToManyRawIdWidgetTest(TestCase):