--- /dev/null
+++ Libc/Libc-1669.0.4/tests/swscanf.c
@@ -0,0 +1,24 @@
+#include <stdio.h>
+#include <wchar.h>
+#include <darwintest.h>
+#include <darwintest_utils.h>
+
+T_DECL(swscanf, "input conversion")
+{
+    wchar_t arg [] = L"abcd efgh ik";
+    wchar_t s[50];
+    int ret = 0;
+
+    (void)wcscpy(s,L"\0");
+    ret = swscanf(s,L"%[Zto]",arg);
+    T_ASSERT_EQ(ret, EOF, "swscanf returned %d", ret);
+}
+
+T_DECL(swscanf_53347577, "rdar://53347577")
+{
+	int a = 0, b = 0, n = 0;
+	T_EXPECT_EQ_INT(swscanf(L"23 19", L"%d %d%n", &a, &b, &n), 2, NULL);
+	T_EXPECT_EQ_INT(a, 23, NULL);
+	T_EXPECT_EQ_INT(b, 19, NULL);
+	T_EXPECT_EQ_INT(n, 5, NULL);
+}