From 977e0c9577818ffcee164a0a19bc3817bb1b133b Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Thu, 9 Jun 2022 21:11:47 -0400
Subject: [PATCH] add test for String.to_hex

---
 src/core/CCString.ml | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/core/CCString.ml b/src/core/CCString.ml
index 6c5ae1c5..3b837ab0 100644
--- a/src/core/CCString.ml
+++ b/src/core/CCString.ml
@@ -1173,9 +1173,11 @@ let of_hex s = try Some (of_hex_exn s) with Invalid_argument _ -> None
 *)
 
 (*$Q
-    Q.(string) (fun s -> \
-        of_hex_exn (to_hex s) = s)
-    *)
+  Q.(string) (fun s -> \
+    of_hex_exn (to_hex s) = s)
+  Q.(string) (fun s -> \
+    String.for_all (function 'A'..'F'|'a'..'f'|'0'..'9' -> true |  _ -> false) @@ to_hex s)
+*)
 
 let pp_buf buf s =
   Buffer.add_char buf '"';