From e42caf3b6a4c566200110e50da36a088fa1c8065 Mon Sep 17 00:00:00 2001
From: Simon Cruanes <simon.cruanes.2007@m4x.org>
Date: Thu, 9 Apr 2026 00:58:25 +0000
Subject: [PATCH] more tests

---
 tests/core/t.ml             |  1 +
 tests/core/t_byte_buffer.ml | 68 +++++++++++++++++++++++++++++++++++++
 tests/core/t_byte_slice.ml  | 37 ++++++++++++++++++++
 3 files changed, 106 insertions(+)
 create mode 100644 tests/core/t_byte_slice.ml

diff --git a/tests/core/t.ml b/tests/core/t.ml
index 8508555a..ad4aa0df 100644
--- a/tests/core/t.ml
+++ b/tests/core/t.ml
@@ -5,6 +5,7 @@ Containers_testlib.run_all ~descr:"containers"
     T_array.get ();
     T_bool.get ();
     T_byte_buffer.get ();
+    T_byte_slice.get ();
     T_canonical_sexp.get ();
     T_char.get ();
     T_either.get ();
diff --git a/tests/core/t_byte_buffer.ml b/tests/core/t_byte_buffer.ml
index 7d9a0d3a..b55f6fc0 100644
--- a/tests/core/t_byte_buffer.ml
+++ b/tests/core/t_byte_buffer.ml
@@ -152,3 +152,71 @@ let prop_consistent ops =
 ;;
 
 q arb (fun ops -> prop_consistent ops)
+;;
+
+(* --- iter/fold_left/iteri off-by-one --- *)
+
+t @@ fun () ->
+(* empty buffer: iter should call f zero times *)
+let b = create () in
+let n = ref 0 in
+iter (fun _ -> incr n) b;
+!n = 0
+;;
+
+t @@ fun () ->
+(* non-empty buffer: iter visits exactly [length b] chars *)
+let b = create () in
+append_string b "abc";
+let chars = ref [] in
+iter (fun c -> chars := c :: !chars) b;
+List.rev !chars = [ 'a'; 'b'; 'c' ]
+;;
+
+t @@ fun () ->
+(* fold_left on empty buffer returns accumulator unchanged *)
+let b = create () in
+fold_left (fun acc _ -> acc + 1) 0 b = 0
+;;
+
+t @@ fun () ->
+(* fold_left counts exactly [length b] chars *)
+let b = create () in
+append_string b "hello";
+fold_left (fun acc _ -> acc + 1) 0 b = 5
+;;
+
+t @@ fun () ->
+(* iteri visits exactly [length b] indices *)
+let b = create () in
+append_string b "ab";
+let pairs = ref [] in
+iteri (fun i c -> pairs := (i, c) :: !pairs) b;
+List.rev !pairs = [ 0, 'a'; 1, 'b' ]
+;;
+
+(* --- copy --- *)
+
+t @@ fun () ->
+let b = create () in
+append_string b "hello";
+let b2 = copy b in
+contents b = contents b2
+;;
+
+t @@ fun () ->
+(* copy is independent: mutating original doesn't affect copy *)
+let b = create () in
+append_string b "hello";
+let b2 = copy b in
+add_char b '!';
+contents b2 = "hello"
+;;
+
+t @@ fun () ->
+(* copy is independent: mutating copy doesn't affect original *)
+let b = create () in
+append_string b "hello";
+let b2 = copy b in
+add_char b2 '?';
+contents b = "hello"
diff --git a/tests/core/t_byte_slice.ml b/tests/core/t_byte_slice.ml
new file mode 100644
index 00000000..01ce67e7
--- /dev/null
+++ b/tests/core/t_byte_slice.ml
@@ -0,0 +1,37 @@
+module T = (val Containers_testlib.make ~__FILE__ ())
+include T
+open CCByte_slice;;
+
+(* --- of_string --- *)
+
+t @@ fun () ->
+let sl = of_string "hello" in
+len sl = 5
+;;
+
+t @@ fun () ->
+let sl = of_string "hello" in
+contents sl = "hello"
+;;
+
+t @@ fun () ->
+let sl = of_string "" in
+len sl = 0
+;;
+
+(* --- clear --- *)
+
+t @@ fun () ->
+let sl = of_string "hello" in
+clear sl;
+len sl = 0
+;;
+
+t @@ fun () ->
+(* after clear, get raises *)
+let sl = of_string "hello" in
+clear sl;
+(try
+   let _ = get sl 0 in
+   false
+ with Invalid_argument _ -> true)