tests/chmod/tests_for_describe_change.c

#include "../../unity/unity.h"
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <errno.h>
#include <fcntl.h>
#include "quote.h"

/* Unity fixtures */
void setUp(void) {
  /* Ensure deterministic messages and quoting */
  setlocale(LC_ALL, "C");
  set_quoting_style(NULL, literal_quoting_style);
}
void tearDown(void) {
  /* no-op */
}

/* Helper: capture stdout produced by describe_change.
   On success, returns malloc'd NUL-terminated string (caller frees).
   On failure, returns NULL (no Unity assertions while stdout is redirected). */
static char* capture_describe_change_output(const char *file, const struct change_status *ch) {
  int pipefd[2];
  if (pipe(pipefd) == -1) {
    return NULL;
  }

  int saved_stdout = dup(STDOUT_FILENO);
  if (saved_stdout == -1) {
    close(pipefd[0]);
    close(pipefd[1]);
    return NULL;
  }

  fflush(stdout);

  if (dup2(pipefd[1], STDOUT_FILENO) == -1) {
    close(saved_stdout);
    close(pipefd[0]);
    close(pipefd[1]);
    return NULL;
  }

  /* We can close the original write end now; stdout holds a dup of it. */
  close(pipefd[1]);

  /* Call the target function; avoid Unity asserts during redirection */
  describe_change(file, ch);

  /* Flush and restore stdout */
  fflush(stdout);
  if (dup2(saved_stdout, STDOUT_FILENO) == -1) {
    /* Even if restore fails, attempt to continue to read what we can */
  }
  close(saved_stdout);

  /* Read all data from the pipe */
  char *buf = NULL;
  size_t cap = 0;
  size_t len = 0;

  char tmp[4096];
  ssize_t n;
  while ((n = read(pipefd[0], tmp, sizeof tmp)) > 0) {
    if (len + (size_t)n + 1 > cap) {
      size_t new_cap = (cap == 0 ? 4096 : cap * 2);
      while (new_cap < len + (size_t)n + 1) new_cap *= 2;
      char *new_buf = (char*)realloc(buf, new_cap);
      if (!new_buf) {
        free(buf);
        close(pipefd[0]);
        return NULL;
      }
      buf = new_buf;
      cap = new_cap;
    }
    memcpy(buf + len, tmp, (size_t)n);
    len += (size_t)n;
  }
  close(pipefd[0]);

  if (!buf) {
    buf = (char*)malloc(1);
    if (!buf) return NULL;
    len = 0;
  }
  buf[len] = '\0';
  return buf;
}

/* Test: CH_NOT_APPLIED message */
void test_describe_change_not_applied(void) {
  struct change_status ch;
  memset(&ch, 0, sizeof ch);
  ch.status = CH_NOT_APPLIED;

  char *out = capture_describe_change_output("file", &ch);
  TEST_ASSERT_NOT_NULL_MESSAGE(out, "Failed to capture output");
  TEST_ASSERT_EQUAL_STRING("neither symbolic link file nor referent has been changed\n", out);
  free(out);
}

/* Test: CH_NO_STAT message */
void test_describe_change_no_stat(void) {
  struct change_status ch;
  memset(&ch, 0, sizeof ch);
  ch.status = CH_NO_STAT;

  char *out = capture_describe_change_output("missing", &ch);
  TEST_ASSERT_NOT_NULL_MESSAGE(out, "Failed to capture output");
  TEST_ASSERT_EQUAL_STRING("missing could not be accessed\n", out);
  free(out);
}

/* Test: CH_SUCCEEDED message with regular file modes */
void test_describe_change_succeeded_basic(void) {
  struct change_status ch;
  memset(&ch, 0, sizeof ch);
  ch.status = CH_SUCCEEDED;
  ch.old_mode = S_IFREG | 0600;
  ch.new_mode = S_IFREG | 0640;

  char *out = capture_describe_change_output("file", &ch);
  TEST_ASSERT_NOT_NULL_MESSAGE(out, "Failed to capture output");
  TEST_ASSERT_EQUAL_STRING(
    "mode of file changed from 0600 (rw-------) to 0640 (rw-r-----)\n",
    out);
  free(out);
}

/* Test: CH_FAILED message with regular file modes */
void test_describe_change_failed_basic(void) {
  struct change_status ch;
  memset(&ch, 0, sizeof ch);
  ch.status = CH_FAILED;
  ch.old_mode = S_IFREG | 0755;
  ch.new_mode = S_IFREG | 0700;

  char *out = capture_describe_change_output("exec", &ch);
  TEST_ASSERT_NOT_NULL_MESSAGE(out, "Failed to capture output");
  TEST_ASSERT_EQUAL_STRING(
    "failed to change mode of exec from 0755 (rwxr-xr-x) to 0700 (rwx------)\n",
    out);
  free(out);
}

/* Test: CH_NO_CHANGE_REQUESTED prints only new mode and perms */
void test_describe_change_no_change_requested_with_setuid(void) {
  struct change_status ch;
  memset(&ch, 0, sizeof ch);
  ch.status = CH_NO_CHANGE_REQUESTED;
  ch.old_mode = S_IFREG | 0600;                 /* old_mode is ignored in this branch */
  ch.new_mode = S_IFREG | S_ISUID | 0755;       /* 04755 -> rwsr-xr-x */

  char *out = capture_describe_change_output("suidbin", &ch);
  TEST_ASSERT_NOT_NULL_MESSAGE(out, "Failed to capture output");
  TEST_ASSERT_EQUAL_STRING(
    "mode of suidbin retained as 4755 (rwsr-xr-x)\n",
    out);
  free(out);
}

/* Test: CH_SUCCEEDED with directory mode; ensure leading file-type char removed */
void test_describe_change_succeeded_directory(void) {
  struct change_status ch;
  memset(&ch, 0, sizeof ch);
  ch.status = CH_SUCCEEDED;
  ch.old_mode = S_IFDIR | 0700;
  ch.new_mode = S_IFDIR | 0777;

  char *out = capture_describe_change_output("dir", &ch);
  TEST_ASSERT_NOT_NULL_MESSAGE(out, "Failed to capture output");
  TEST_ASSERT_EQUAL_STRING(
    "mode of dir changed from 0700 (rwx------) to 0777 (rwxrwxrwx)\n",
    out);
  free(out);
}

int main(void) {
  UNITY_BEGIN();
  RUN_TEST(test_describe_change_not_applied);
  RUN_TEST(test_describe_change_no_stat);
  RUN_TEST(test_describe_change_succeeded_basic);
  RUN_TEST(test_describe_change_failed_basic);
  RUN_TEST(test_describe_change_no_change_requested_with_setuid);
  RUN_TEST(test_describe_change_succeeded_directory);
  return UNITY_END();
}