(** Tests for JSON decode/encode roundtrips through the bytesrw streaming I/O
    surface. *)

let test_decode_primitive () =
  match Json.of_string Json.Codec.int "42" with
  | Error e -> Alcotest.failf "decode failed: %a" Json.Error.pp e
  | Ok n -> Alcotest.(check int) "42 round-trip" 42 n

let test_encode_primitive () =
  let s = Json.to_string Json.Codec.int 7 in
  Alcotest.(check string) "7 encoded" "7" s

let test_roundtrip_object () =
  let pair_codec =
    let open Json.Codec.Object in
    map ~kind:"pair" (fun a b -> (a, b))
    |> member "a" Json.Codec.int ~enc:fst
    |> member "b" Json.Codec.string ~enc:snd
    |> seal
  in
  let input = {|{"a": 7, "b": "hi"}|} in
  match Json.of_string pair_codec input with
  | Error e -> Alcotest.failf "decode failed: %a" Json.Error.pp e
  | Ok (a, b) ->
      Alcotest.(check int) "a" 7 a;
      Alcotest.(check string) "b" "hi" b

let test_decode_error () =
  match Json.of_string Json.Codec.int "not json" with
  | Ok _ -> Alcotest.fail "expected decode error"
  | Error _ -> ()

let suite =
  ( "json_bytesrw",
    [
      Alcotest.test_case "decode int" `Quick test_decode_primitive;
      Alcotest.test_case "encode int" `Quick test_encode_primitive;
      Alcotest.test_case "roundtrip object" `Quick test_roundtrip_object;
      Alcotest.test_case "decode error" `Quick test_decode_error;
    ] )