1 files changed, 19 insertions, 0 deletions
diff --git a/library/std/src/sys_common/bytestring/tests.rs b/library/std/src/sys_common/bytestring/tests.rs
new file mode 100644
index 00000000000..1685f087d18
--- /dev/null
+++ b/library/std/src/sys_common/bytestring/tests.rs
@@ -0,0 +1,19 @@
+use super::*;
+use crate::fmt::{Debug, Formatter, Result};
+
+#[test]
+fn smoke() {
+    struct Helper<'a>(&'a [u8]);
+
+    impl Debug for Helper<'_> {
+        fn fmt(&self, f: &mut Formatter<'_>) -> Result {
+            debug_fmt_bytestring(self.0, f)
+        }
+    }
+
+    let input = b"\xF0hello,\tworld";
+    let expected = r#""\xF0hello,\tworld""#;
+    let output = format!("{:?}", Helper(input));
+
+    assert!(output == expected);
+}