tests: Even more work on error handling

realpath: Fixing undefined behaviour in the second test. If the call fails the resolved_name argument cannot be used for error checking because its state is undefined by SUSv2.
pipe: Changing the order of close and write error handling code. Errors in close could overwrite errno after write errors, returning incorrect error messages.
gmtime: Removed duplicate checks
Other fixes for fseek, rename, mktime, putwchar

tests/stdio/fseek.c

@@ -16,5 +16,5 @@ int main(void) {
 
     off_t pos = ftello(f);
     ERROR_IF(ftello, pos, == -1);
-    printf("ftell: %ld\n", pos);
+    printf("ftello: %ld\n", pos);
 }

tests/stdio/rename.c

@@ -49,9 +49,8 @@ int main(void) {
     UNEXP_IF(remove, rm_status, != 0);
 
     // Compare file contents
-    if (strcmp(str, buf) == 0) {
-        exit(EXIT_SUCCESS);
-    } else {
+    if (strcmp(str, buf) != 0) {
+        puts("Comparison failed!");
         exit(EXIT_FAILURE);
     }
 }

tests/stdlib/realpath.c

@@ -7,25 +7,14 @@
 #include "test_helpers.h"
 
 int main(void) {
-    char* path = realpath("stdlib/realpath.c", NULL);
-    if (!path) {
-        perror("realpath");
-        exit(EXIT_FAILURE);
-    }
-    puts(path);
+    char *path_res = realpath("stdlib/realpath.c", NULL);
+    ERROR_IF(realpath, path_res, == NULL);
+    puts(path_res);
+    free(path_res);
 
-    free(path);
-
-    path = malloc(PATH_MAX);
-    memset(path, 0, PATH_MAX);
-
-    realpath("stdlib/realpath.c", path);
-    if (!path) {
-        perror("realpath");
-        free(path);
-        exit(EXIT_FAILURE);
-    }
-    puts(path);
-
-    free(path);
+    char path_arg[PATH_MAX] = { 0 };
+    char *res = realpath("stdlib/realpath.c", path_arg);
+    ERROR_IF(realpath, res, == NULL);
+    puts(path_arg);
+    free(path_arg);
 }

tests/time/gmtime.c

@@ -18,12 +18,4 @@ int main(void) {
         info->tm_gmtoff != expected.tm_gmtoff || strcmp(info->tm_zone, expected.tm_zone) != 0) {
             exit(EXIT_FAILURE);
     }
-
-    if (info->tm_sec != expected.tm_sec || info->tm_min != expected.tm_min ||
-        info->tm_hour != expected.tm_hour || info->tm_mday != expected.tm_mday ||
-        info->tm_year != expected.tm_year || info->tm_wday != expected.tm_wday ||
-        info->tm_yday != expected.tm_yday || info->tm_isdst != expected.tm_isdst ||
-        info->tm_gmtoff != expected.tm_gmtoff || strcmp(info->tm_zone, expected.tm_zone) != 0) {
-            exit(EXIT_FAILURE);
-    }
 }

tests/time/mktime.c

@@ -6,11 +6,15 @@
 #include "test_helpers.h"
 
 int check(time_t input) {
-    struct tm* t = localtime(&input);
+    struct tm *t = localtime(&input);
+    ERROR_IF(localtime, t, == NULL);
 
-    printf("%ld = %ld\n", input, mktime(t));
+    time_t output = mktime(t);
+    ERROR_IF(mktime, output, == (time_t)-1);
 
-    if (input != mktime(t)) {
+    printf("%ld = %ld\n", input, output);
+
+    if (input != output) {
         printf(
             "Year %d, Day of year: %d, Month %d, Day of month: %d, Day of week: %d, %d:%d:%d\n",
             t->tm_year, t->tm_yday, t->tm_mon, t->tm_mday, t->tm_wday, t->tm_hour, t->tm_min, t->tm_sec
@@ -41,8 +45,13 @@ int main(void) {
 
     for (int i = 0; i < 10; i += 1) {
         time_t input = (time_t) rand();
-        struct tm* time = localtime(&input);
+
+        struct tm *time = localtime(&input);
+        ERROR_IF(localtime, time, == NULL);
+
         time_t output = mktime(time);
+        ERROR_IF(mktime, output, == (time_t)-1);
+
         if (input != output) {
             // asctime has newline
             printf("Comparison %ld == %ld failed. Time: %s", input, output, asctime(time));

tests/unistd/pipe.c

@@ -7,57 +7,56 @@
 #include "test_helpers.h"
 
 int main(void) {
-    int pid, pip[2];
+    int pip[2];
     char instring[20];
-    char * outstring = "Hello World!";
+    char *outstring = "Hello World!";
 
-    if (pipe(pip) < 0) {
-        perror("pipe");
-        exit(EXIT_FAILURE);
-    }
+    int pipe_status = pipe(pip);
+    ERROR_IF(pipe, pipe_status, == -1);
+    UNEXP_IF(pipe, pipe_status, != 0);
 
-    pid = fork();
-    if (pid == 0)           /* child : sends message to parent*/
-    {
-        /* close read end */
-        close(pip[0]);
+    int pid = fork();
+    ERROR_IF(fork, pid, == -1);
 
-        /* send 7 characters in the string, including end-of-string */
+    if (pid == 0) {
+        // child: sends message to parent
+        // close read end
+        int cr = close(pip[0]);
+        ERROR_IF(close, cr, == -1);
+        UNEXP_IF(close, cr, != 0);
+
+        // send 7 characters in the string, including end-of-string
         int bytes = write(pip[1], outstring, strlen(outstring));
+        ERROR_IF(write, bytes, == -1);
 
-        /* close write end */
-        close(pip[1]);
-
-        /* check result */
-        if (bytes < 0) {
-            perror("pipe write");
-            exit(EXIT_FAILURE);
-        } else if (bytes != strlen(outstring)) {
+        // check result
+        if (bytes != strlen(outstring)) {
             fprintf(stderr, "pipe write: %d != %ld\n", bytes, strlen(outstring));
             exit(EXIT_FAILURE);
         }
 
-        exit(EXIT_SUCCESS);
-    }
-    else			/* parent : receives message from child */
-    {
-        /* close write end */
-        close(pip[1]);
+        // close write end
+        int cw = close(pip[1]);
+        ERROR_IF(close, cw, == -1);
+        UNEXP_IF(close, cw, != 0);
 
-        /* clear memory */
+        exit(EXIT_SUCCESS);
+    } else {
+        // parent: receives message from child
+        // close write end
+        int cw = close(pip[1]);
+        ERROR_IF(close, cw, == -1);
+        UNEXP_IF(close, cw, != 0);
+
+        // clear memory
         memset(instring, 0, sizeof(instring));
 
-        /* read from the pipe */
+        // read from the pipe
         int bytes = read(pip[0], instring, sizeof(instring) - 1);
+        ERROR_IF(read, bytes, == -1);
 
-        /* close read end */
-        close(pip[0]);
-
-        /* check result */
-        if (bytes < 0) {
-            perror("pipe read");
-            exit(EXIT_FAILURE);
-        } else if (bytes != strlen(outstring)) {
+        // check result
+        if (bytes != strlen(outstring)) {
             fprintf(stderr, "pipe read: %d != %ld\n", bytes, strlen(outstring));
             exit(EXIT_FAILURE);
         } else if (memcmp(instring, outstring, strlen(outstring)) != 0) {
@@ -67,6 +66,11 @@ int main(void) {
             printf("%s\n", instring);
         }
 
+        // close read end
+        int cr = close(pip[0]);
+        ERROR_IF(close, cr, == -1);
+        UNEXP_IF(close, cr, != 0);
+
         exit(EXIT_SUCCESS);
     }
 }

tests/wchar/putwchar.c

@@ -8,13 +8,8 @@
 int main(void) {
     wchar_t *wcs = L"zß水🍌";
 
-    int i;
-    for (i = 0; wcs[i] != L'\0'; i++)
-    {
-        if (0xFFFFFFFFu == putwchar(wcs[i]))
-        {
-            printf("Unable to putwchar() the wide character.\n");
-            exit(EXIT_FAILURE);
-        }
+    for (int i = 0; wcs[i] != L'\0'; i++) {
+        wint_t status = putwchar(wcs[i]);
+        ERROR_IF(putwchar, status, == WEOF);
     }
 }