fs: translate error code properly in cpSync

UV error code needs to be negative integer so it can be mapped
correctly. The filesystem error are positive integer, so we need to
handle it before throwing.

Co-authored-by: Jake Yuesong Li <jake.yuesong@gmail.com>

Author: jazelly

src/node_file.cc

@@ -3147,7 +3147,11 @@ static void CpSyncCheckPaths(const FunctionCallbackInfo<Value>& args) {
                         ? std::filesystem::symlink_status(src_path, error_code)
                         : std::filesystem::status(src_path, error_code);
   if (error_code) {
-    return env->ThrowUVException(EEXIST, "lstat", nullptr, src.out());
+    return env->ThrowUVException(
+        error_code.value() > 0 ? -error_code.value() : error_code.value(),
+        dereference ? "stat" : "lstat",
+        nullptr,
+        src.out());
   }
   auto dest_status =
       dereference ? std::filesystem::symlink_status(dest_path, error_code)

test/parallel/test-fs-cp.mjs

@@ -419,6 +419,26 @@ if (!isWindows) {
   );
 }
 
+// It throws error when attempting to copy a file with a name that is too long.
+{
+  const src = 'a'.repeat(5000);
+  const dest = nextdir();
+  assert.throws(
+    () => cpSync(src, dest, mustNotMutateObjectDeep()),
+    { code: 'ENAMETOOLONG' }
+  );
+}
+
+// It throws error when attempting to copy a dir that does not exist.
+{
+  const src = nextdir();
+  const dest = nextdir();
+  assert.throws(
+    () => cpSync(src, dest, mustNotMutateObjectDeep({ recursive: true })),
+    { code: 'ENOENT' }
+  );
+}
+
 // It makes file writeable when updating timestamp, if not writeable.
 {
   const src = nextdir();