--- /dev/null
+++ libmalloc/libmalloc-521.120.7/tests/xzone_testing.h
@@ -0,0 +1,31 @@
+#ifndef __XZONE_TESTING_H__
+#define __XZONE_TESTING_H__
+
+#include <darwintest.h>
+
+#include <../src/internal.h>
+
+#if CONFIG_XZONE_MALLOC
+
+extern malloc_zone_t **malloc_zones;
+
+static inline void
+assert_zone_is_xzone_malloc(malloc_zone_t *zone)
+{
+	T_ASSERT_GE(zone->version, 14, "zone version");
+	T_ASSERT_EQ(zone->introspect->zone_type, MALLOC_ZONE_TYPE_XZONE,
+			"zone is xzone malloc");
+}
+
+static inline xzm_malloc_zone_t
+get_default_xzone_zone(void)
+{
+	malloc_zone_t *dz = malloc_zones[0];
+	assert_zone_is_xzone_malloc(dz);
+
+	return (xzm_malloc_zone_t)dz;
+}
+
+#endif // CONFIG_XZONE_MALLOC
+
+#endif // __XZONE_TESTING_H__