1 files changed, 13 insertions, 0 deletions
diff --git a/library/std/src/sys/windows/os/tests.rs b/library/std/src/sys/windows/os/tests.rs
new file mode 100644
index 000000000..458d6e11c
--- /dev/null
+++ b/library/std/src/sys/windows/os/tests.rs
@@ -0,0 +1,13 @@
+use crate::io::Error;
+use crate::sys::c;
+
+// tests `error_string` above
+#[test]
+fn ntstatus_error() {
+    const STATUS_UNSUCCESSFUL: u32 = 0xc000_0001;
+    assert!(
+        !Error::from_raw_os_error((STATUS_UNSUCCESSFUL | c::FACILITY_NT_BIT) as _)
+            .to_string()
+            .contains("FormatMessageW() returned error")
+    );
+}