;;; bindat-tests.el --- tests for bindat.el -*- lexical-binding: t -*-
;; Copyright (C) 2019-2025 Free Software Foundation, Inc.
;; This file is part of GNU Emacs.
;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
;;; Code:
(require 'ert)
(require 'bindat)
(require 'cl-lib)
(bindat-defmacro ip () "An IPv4 address" '(vec 4 byte))
(defconst header-bindat-spec
(bindat-type
(dest-ip ip)
(src-ip ip)
(dest-port uint 16)
(src-port uint 16)))
(defconst data-bindat-spec
(bindat-type
(type u8)
(opcode u8)
(length uint 16 'le) ;; little endian order
(id strz 8)
(data vec length)
(_ align 4)))
(defconst packet-bindat-spec
(bindat-type
(header type header-bindat-spec)
(items u8)
(_ fill 3)
(item repeat items
(_ type data-bindat-spec))))
(defconst struct-bindat
'((header
(dest-ip . [192 168 1 100])
(src-ip . [192 168 1 101])
(dest-port . 284)
(src-port . 5408))
(items . 2)
(item ((type . 2)
(opcode . 3)
(length . 5)
(id . "ABCDEF")
(data . [1 2 3 4 5]))
((type . 1)
(opcode . 4)
(length . 7)
(id . "BCDEFG")
(data . [6 7 8 9 10 11 12])))))
(ert-deftest bindat-test-pack ()
(should (equal
(cl-map 'vector #'identity
(bindat-pack packet-bindat-spec struct-bindat))
[ 192 168 1 100 192 168 1 101 01 28 21 32 2 0 0 0
2 3 5 0 ?A ?B ?C ?D ?E ?F 0 0 1 2 3 4 5 0 0 0
1 4 7 0 ?B ?C ?D ?E ?F ?G 0 0 6 7 8 9 10 11 12 0 ])))
(ert-deftest bindat-test-unpack ()
(should (equal
(bindat-unpack packet-bindat-spec
(bindat-pack packet-bindat-spec struct-bindat))
struct-bindat)))
(ert-deftest bindat-test-pack/multibyte-string-fails ()
(should-error (bindat-pack nil nil "ö")))
(ert-deftest bindat-test-unpack/multibyte-string-fails ()
(should-error (bindat-unpack nil "ö")))
(ert-deftest bindat-test-format-vector ()
(should (equal (bindat-format-vector [1 2 3] "%d" "x" 2) "1x2"))
(should (equal (bindat-format-vector [1 2 3] "%d" "x") "1x2x3")))
(ert-deftest bindat-test-vector-to-dec ()
(should (equal (bindat-vector-to-dec [1 2 3]) "1.2.3"))
(should (equal (bindat-vector-to-dec [2048 1024 512] ".") "2048.1024.512")))
(ert-deftest bindat-test-vector-to-hex ()
(should (equal (bindat-vector-to-hex [1 2 3]) "01:02:03"))
(should (equal (bindat-vector-to-hex [2048 1024 512] ".") "800.400.200")))
(ert-deftest bindat-test-ip-to-string ()
(should (equal (bindat-ip-to-string [192 168 0 1]) "192.168.0.1"))
(should (equal (bindat-ip-to-string "\300\250\0\1") "192.168.0.1")))
(defconst bindat-test--int-websocket-type
(bindat-type
:pack-var value
(n1 u8
:pack-val (if (< value 126) value (if (< value 65536) 126 127)))
(n2 uint (pcase n1 (127 64) (126 16) (_ 0))
:pack-val value)
:unpack-val (if (< n1 126) n1 n2)))
(ert-deftest bindat-test--pack-val ()
;; This is intended to test the :(un)pack-val feature that offers
;; control over the unpacked representation of the data.
(dolist (n '(0 42 125 126 127 128 150 255 5000 65535 65536 8769786876))
(should
(equal (bindat-unpack bindat-test--int-websocket-type
(bindat-pack bindat-test--int-websocket-type n))
n))))
(ert-deftest bindat-test--sint ()
(dotimes (kind 32)
(let ((bitlen (* 8 (/ kind 2)))
(r (evenp kind)))
(dotimes (_ 100)
(let* ((n (random (ash 1 bitlen)))
(i (- n (ash 1 (1- bitlen))))
(stype (bindat-type sint bitlen r))
(utype (bindat-type if r (uintr bitlen) (uint bitlen))))
(should (equal (bindat-unpack
stype
(bindat-pack stype i))
i))
(when (>= i 0)
(should (equal (bindat-pack utype i)
(bindat-pack stype i)))
(should (equal (bindat-unpack utype (bindat-pack stype i))
i))))))))
(defconst bindat-test--LEB128
(bindat-type
letrec ((loop
(struct :pack-var n
(head u8
:pack-val (+ (logand n 127) (if (> n 127) 128 0)))
(tail if (< head 128) (unit 0) loop
:pack-val (ash n -7))
:unpack-val (+ (logand head 127) (ash tail 7)))))
loop))
(ert-deftest bindat-test--recursive ()
(dotimes (n 10)
(let ((max (ash 1 (* n 10))))
(dotimes (_ 10)
(let ((n (random max)))
(should (equal (bindat-unpack bindat-test--LEB128
(bindat-pack bindat-test--LEB128 n))
n)))))))
(ert-deftest bindat-test--str-strz-prealloc ()
(dolist (tc `(((,(bindat-type str 1) "") . "xx")
((,(bindat-type str 2) "") . "xx")
((,(bindat-type str 2) "a") . "ax")
((,(bindat-type str 2) "ab") . "ab")
((,(bindat-type str 2) "abc") . "ab")
((((x str 1)) ((x . ""))) . "xx")
((((x str 2)) ((x . ""))) . "xx")
((((x str 2)) ((x . "a"))) . "ax")
((((x str 2)) ((x . "ab"))) . "ab")
((((x str 2)) ((x . "abc"))) . "ab")
((,(bindat-type strz 1) "") . "\0x")
((,(bindat-type strz 2) "") . "\0x")
((,(bindat-type strz 2) "a") . "a\0")
((,(bindat-type strz 2) "ab") . "ab")
((,(bindat-type strz 2) "abc") . "ab")
((((x strz 1)) ((x . ""))) . "\0x")
((((x strz 2)) ((x . ""))) . "\0x")
((((x strz 2)) ((x . "a"))) . "a\0")
((((x strz 2)) ((x . "ab"))) . "ab")
((((x strz 2)) ((x . "abc"))) . "ab")
((,(bindat-type strz) "") . "\0x")
((,(bindat-type strz) "a") . "a\0")))
(let ((prealloc (make-string 2 ?x)))
(apply #'bindat-pack (append (car tc) (list prealloc)))
(should (equal prealloc (cdr tc))))))
(ert-deftest bindat-test--str-strz-multibyte ()
(dolist (spec (list (bindat-type str 2)
(bindat-type strz 2)
(bindat-type strz)))
(should (equal (bindat-pack spec (string-to-multibyte "x")) "x\0"))
(should (equal (bindat-pack spec (string-to-multibyte "\xff")) "\xff\0"))
(should-error (bindat-pack spec "💩"))
(should-error (bindat-pack spec "\N{U+ff}")))
(dolist (spec (list '((x str 2)) '((x strz 2))))
(should (equal (bindat-pack spec `((x . ,(string-to-multibyte "x"))))
"x\0"))
(should (equal (bindat-pack spec `((x . ,(string-to-multibyte "\xff"))))
"\xff\0"))
(should-error (bindat-pack spec '((x . "💩"))))
(should-error (bindat-pack spec '((x . "\N{U+ff}"))))))
(let ((spec (bindat-type strz 2)))
(ert-deftest bindat-test--strz-fixedlen-len ()
(should (equal (bindat-length spec "") 2))
(should (equal (bindat-length spec "a") 2)))
(ert-deftest bindat-test--strz-fixedlen-len-overflow ()
(should (equal (bindat-length spec "ab") 2))
(should (equal (bindat-length spec "abc") 2)))
(ert-deftest bindat-test--strz-fixedlen-pack ()
(should (equal (bindat-pack spec "") "\0\0"))
(should (equal (bindat-pack spec "a") "a\0")))
(ert-deftest bindat-test--strz-fixedlen-pack-overflow ()
;; This is not the only valid semantic, but it's the one we've
;; offered historically.
(should (equal (bindat-pack spec "ab") "ab"))
(should (equal (bindat-pack spec "abc") "ab")))
(ert-deftest bindat-test--strz-fixedlen-unpack ()
(should (equal (bindat-unpack spec "\0\0") ""))
(should (equal (bindat-unpack spec "\0X") ""))
(should (equal (bindat-unpack spec "a\0") "a"))
;; Same comment as for b-t-s-f-pack-overflow.
(should (equal (bindat-unpack spec "ab") "ab"))
;; Missing null terminator.
(should-error (bindat-unpack spec ""))
(should-error (bindat-unpack spec "a"))))
(let ((spec (bindat-type strz)))
(ert-deftest bindat-test--strz-varlen-len ()
(should (equal (bindat-length spec "") 1))
(should (equal (bindat-length spec "abc") 4)))
(ert-deftest bindat-test--strz-varlen-pack ()
(should (equal (bindat-pack spec "") "\0"))
(should (equal (bindat-pack spec "abc") "abc\0"))
;; Null bytes in the input string break unpacking.
(should-error (bindat-pack spec "\0"))
(should-error (bindat-pack spec "\0x"))
(should-error (bindat-pack spec "x\0"))
(should-error (bindat-pack spec "x\0y")))
(ert-deftest bindat-test--strz-varlen-unpack ()
(should (equal (bindat-unpack spec "\0") ""))
(should (equal (bindat-unpack spec "abc\0") "abc"))
;; Missing null terminator.
(should-error (bindat-unpack spec ""))
(should-error (bindat-unpack spec "a")))
(ert-deftest bindat-test--strz-array-unpack ()
(should (equal (bindat-unpack spec [#x61 #x62 #x63 #x00]) "abc"))))
(let ((spec (bindat-type str 3)))
(ert-deftest bindat-test--str-simple-array-unpack ()
(should (equal (bindat-unpack spec [#x61 #x62 #x63]) "abc"))))
(let ((spec (bindat-type
(first u8)
(string str 3)
(last uint 16))))
(ert-deftest bindat-test--str-combined-array-unpack ()
(let ((unpacked (bindat-unpack spec [#xff #x63 #x62 #x61 #xff #xff])))
(should (equal (bindat-get-field unpacked 'string) "cba"))
(should (equal (bindat-get-field unpacked 'first) (- (expt 2 8) 1)))
(should (equal (bindat-get-field unpacked 'last) (- (expt 2 16) 1))))))
(let ((spec '((x strz 2))))
(ert-deftest bindat-test--strz-legacy-fixedlen-len ()
(should (equal (bindat-length spec '((x . ""))) 2))
(should (equal (bindat-length spec '((x . "a"))) 2)))
(ert-deftest bindat-test--strz-legacy-fixedlen-len-overflow ()
(should (equal (bindat-length spec '((x . "ab"))) 2))
(should (equal (bindat-length spec '((x . "abc"))) 2)))
(ert-deftest bindat-test--strz-legacy-fixedlen-pack ()
(should (equal (bindat-pack spec '((x . ""))) "\0\0"))
(should (equal (bindat-pack spec '((x . "a"))) "a\0")))
(ert-deftest bindat-test--strz-legacy-fixedlen-pack-overflow ()
;; Same comment as for b-t-s-f-pack-overflow.
(should (equal (bindat-pack spec '((x . "ab"))) "ab"))
(should (equal (bindat-pack spec '((x . "abc"))) "ab")))
(ert-deftest bindat-test--strz-legacy-fixedlen-unpack ()
(should (equal (bindat-unpack spec "\0\0") '((x . ""))))
(should (equal (bindat-unpack spec "\0X") '((x . ""))))
(should (equal (bindat-unpack spec "a\0") '((x . "a"))))
;; Same comment as for b-t-s-f-pack-overflow.
(should (equal (bindat-unpack spec "ab") '((x . "ab"))))
;; Missing null terminator.
(should-error (bindat-unpack spec ""))
(should-error (bindat-unpack spec "a"))))
;;; bindat-tests.el ends here