Use assert in test_unlink.cpp NFC (#23174)

This is shorter and the failures give more information.

Author: hoodmane

test/other/test_unlink.cpp

@@ -10,6 +10,7 @@
 #include <string.h>
 #include <sys/stat.h>
 #include <unistd.h>
+#include <assert.h>
 
 #ifdef WASMFS
 #include "../wasmfs/get_backend.h"
@@ -31,72 +32,42 @@ int main() {
 
   // Create a file
   int fd = open(filename, O_RDWR | O_CREAT, 0777);
-  if (fd == -1) {
-    return 1;
-  }
+  assert(fd != -1);
   // Check it exists
-  if (access(filename, F_OK) != 0) {
-    return 1;
-  }
+  assert(access(filename, F_OK) == 0);
   // Delete the file
-  if (unlinkat(AT_FDCWD, filename, 0)) {
-    return 1;
-  }
+  assert(unlinkat(AT_FDCWD, filename, 0) == 0);
   // Check that it doesn't exist
-  if (access(filename, F_OK) != -1) {
-    return 1;
-  }
+  assert(access(filename, F_OK) == -1);
   // Check that we can still write to it
-  if (write(fd, "hello", 5) != 5) {
-    return 1;
-  }
+  assert(write(fd, "hello", 5) == 5);
   // And seek in it.
-  if (lseek(fd, 0, SEEK_SET) != 0) {
-    return 1;
-  }
+  assert(lseek(fd, 0, SEEK_SET) == 0);
   // And read from it.
   char buf[6] = {0};
   auto r = read(fd, buf, 5);
-  if (r != 5) {
-    return 1;
-  }
-  if (strcmp("hello", buf) != 0) {
-    return 1;
-  }
-  if (close(fd)) {
-    return 1;
-  }
+  assert(r==5);
+  assert(strcmp("hello", buf) == 0);
+  assert(close(fd)==0);
 
   // Create a directory
-  if (mkdir(dirname, 0700) != 0) {
-    return 1;
-  }
+  assert(mkdir(dirname, 0700) == 0);
   // Open the directory
   DIR* d = opendir(dirname);
-  if (d == NULL) {
-    return 1;
-  }
+  assert(d != NULL);
   // Delete the directory
-  if (unlinkat(AT_FDCWD, dirname, AT_REMOVEDIR)) {
-    return 1;
-  }
+  assert(unlinkat(AT_FDCWD, dirname, AT_REMOVEDIR) == 0);
   // Check that it doesn't exist
-  if (access(dirname, F_OK) != -1) {
-    return 1;
-  }
+  assert(access(dirname, F_OK) == -1);
 
   // The rest of this test does not yet pass with the node backend!
 #ifndef WASMFS_NODE_BACKEND
 
   // Check that we can still read the directory, but that it is empty.
   errno = 0;
-  if (readdir(d) != NULL || errno != 0) {
-    return 1;
-  }
+  assert(readdir(d) == NULL && errno == 0);
   // Check that we *cannot* create a child.
-  if (openat(dirfd(d), filename, O_CREAT | O_WRONLY, S_IRWXU) != -1) {
-    return 1;
-  }
+  assert(openat(dirfd(d), filename, O_CREAT | O_WRONLY, S_IRWXU) == -1);
   printf("%s\n", strerror(errno));
 #ifdef __EMSCRIPTEN__
   // Linux allows "." and ".." to be accessed on unlinked directories, but this
@@ -105,27 +76,19 @@ int main() {
   // TODO: Consider supporting "." on unlinked files, if not ".."
 
   // Check that we cannot still access "."
-  if (openat(dirfd(d), ".", O_DIRECTORY | O_RDONLY) != -1) {
-    return 1;
-  }
+  assert(openat(dirfd(d), ".", O_DIRECTORY | O_RDONLY) == -1);
 #ifdef WASMFS
   // Check that we cannot still access ".." on WasmFS.
-  if (openat(dirfd(d), "..", O_DIRECTORY | O_RDONLY) != -1) {
-    return 1;
-  }
+  assert(openat(dirfd(d), "..", O_DIRECTORY | O_RDONLY) == -1);
 #endif
 #else
   // Check that we can still access "." on Linux.
   int self = openat(dirfd(d), ".", O_DIRECTORY | O_RDONLY);
-  if (self == -1) {
-    return 1;
-  }
+  assert(self != -1);
   close(self);
   // Check that we can still access ".." on Linux.
   int parent = openat(dirfd(d), "..", O_DIRECTORY | O_RDONLY);
-  if (parent == -1) {
-    return 1;
-  }
+  assert(parent != -1);
   close(parent);
 #endif