--- /dev/null
+/* Test of host and network byte order conversion functions.
+ Copyright (C) 2024 Free Software Foundation, Inc.
+
+ This file 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.
+
+ This file 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 this program. If not, see <https://www.gnu.org/licenses/>. */
+
+/* Written by Collin Funk <collin.funk1@gmail.com>, 2024. */
+
+#include <config.h>
+
+/* Specification. */
+#include <arpa/inet.h>
+
+#include <endian.h>
+#include <stdint.h>
+
+#include "macros.h"
+
+/* Test byte order conversion functions with constant values. */
+static void
+test_convert_constant (void)
+{
+#if BYTE_ORDER == BIG_ENDIAN
+ /* 16-bit. */
+ ASSERT (htons (UINT16_C (0x1234)) == UINT16_C (0x1234));
+ ASSERT (ntohs (UINT16_C (0x1234)) == UINT16_C (0x1234));
+
+ /* 32-bit. */
+ ASSERT (htonl (UINT32_C (0x12345678)) == UINT32_C (0x12345678));
+ ASSERT (ntohl (UINT32_C (0x12345678)) == UINT32_C (0x12345678));
+#else
+ /* 16-bit. */
+ ASSERT (htons (UINT16_C (0x1234)) == UINT16_C (0x3412));
+ ASSERT (ntohs (UINT16_C (0x1234)) == UINT16_C (0x3412));
+
+ /* 32-bit. */
+ ASSERT (htonl (UINT32_C (0x12345678)) == UINT32_C (0x78563412));
+ ASSERT (ntohl (UINT32_C (0x12345678)) == UINT32_C (0x78563412));
+#endif
+}
+
+/* Test that the byte order conversion functions evaluate their
+ arguments once. */
+static void
+test_convert_eval_once (void)
+{
+ /* 16-bit. */
+ {
+ uint16_t value = 0;
+ ASSERT (htons (value++) == 0);
+ ASSERT (value == 1);
+ }
+ {
+ uint16_t value = 0;
+ ASSERT (ntohs (value++) == 0);
+ ASSERT (value == 1);
+ }
+
+ /* 32-bit. */
+ {
+ uint32_t value = 0;
+ ASSERT (htonl (value++) == 0);
+ ASSERT (value == 1);
+ }
+ {
+ uint32_t value = 0;
+ ASSERT (ntohl (value++) == 0);
+ ASSERT (value == 1);
+ }
+}
+
+/* Test that the byte order conversion functions accept floating-point
+ arguments. */
+static void
+test_convert_double (void)
+{
+ /* 16-bit. */
+ ASSERT (htons (0.0) == 0);
+ ASSERT (ntohs (0.0) == 0);
+
+ /* 32-bit. */
+ ASSERT (htonl (0.0) == 0);
+ ASSERT (ntohs (0.0) == 0);
+}
+
+int
+main (void)
+{
+ test_convert_constant ();
+ test_convert_eval_once ();
+ test_convert_double ();
+
+ return test_exit_status;
+}