/*      $OpenBSD: test___fwriting.c,v 1.1 2025/05/25 00:20:54 yasuoka Exp $     */

/*
 * Copyright (c) 2025 YASUOKA Masahiko <yasuoka@yasuoka.net>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include <assert.h>
#include <stdio.h>
#include <stdio_ext.h>
#include <stdlib.h>

/* we use assert() */
#undef  NDEBUG

#define TMPFILENAME     "test___fwriting.tmp"

void test___fwriting0(void);
void test___fwriting1(void);

void
test___fwriting0(void)
{
        FILE    *fp;
        int      r;

        fp = fopen(TMPFILENAME, "w");   /* write only */
        assert(fp != NULL);
        assert(__fwriting(fp) != 0);    /* writing is true immediately */
        r = fputs("Hello world\n", fp);
        assert(r >= 0);
        r = fclose(fp);
        assert(r == 0);

        fp = fopen(TMPFILENAME, "a");   /* append only */
        assert(fp != NULL);
        assert(__fwriting(fp) != 0);    /* writing immediately */
        r = fclose(fp);
        assert(r == 0);
}

void
test___fwriting1(void)
{
        FILE    *fp;
        int      r;

        fp = fopen(TMPFILENAME, "w+");  /* read / write */
        assert(fp != NULL);
        r = fputs("Hello world\n", fp);
        assert(r >= 0);
        assert(__fwriting(fp) != 0);
        rewind(fp);
        assert(fgetc(fp) == 'H');       /* read */
        assert(__fwriting(fp) == 0);    /* writing becomes false */
        fputc('e', fp);
        assert(__fwriting(fp) != 0);    /* writing becomes true */
        ungetc('e', fp);
        assert(__fwriting(fp) == 0);    /* ungetc -> writing becomes false */

        r = fclose(fp);
        assert(r == 0);
}

int
main(int argc, char *argv[])
{
        test___fwriting0();
        test___fwriting1();

        exit(0);
}