safelog: tests for BoxSensitive.

crates/safelog/src/lib.rs

@@ -386,6 +386,23 @@ mod test {
         assert_eq!(s2, expect);
     }
 
+    #[test]
+    #[serial]
+    fn box_sensitive() {
+        let b: BoxSensitive<_> = "hello world".into();
+
+        assert_eq!(b.clone().into_inner(), "hello world");
+
+        let closure = || format!("{} {:?}", b, b);
+        assert_eq!(closure(), "[scrubbed] [scrubbed]");
+        assert_eq!(
+            with_safe_logging_suppressed(closure),
+            r#"hello world "hello world""#
+        );
+
+        assert_eq!(b.len(), 11);
+    }
+
     #[test]
     #[serial]
     fn test_redacted() {