fs: fix cpSync to handle non-ASCII characters

src/node_file.cc

@@ -3425,15 +3425,18 @@ static void CpSyncOverrideFile(const FunctionCallbackInfo<Value>& args) {
   THROW_IF_INSUFFICIENT_PERMISSIONS(
       env, permission::PermissionScope::kFileSystemWrite, dest.ToStringView());
 
+  auto src_path = src.ToPath();
+  auto dest_path = dest.ToPath();
+
   std::error_code error;
 
-  if (!std::filesystem::remove(*dest, error)) {
+  if (!std::filesystem::remove(dest_path, error)) {
     return env->ThrowStdErrException(error, "unlink", *dest);
   }
 
   if (mode == 0) {
     // if no mode is specified use the faster std::filesystem API
-    if (!std::filesystem::copy_file(*src, *dest, error)) {
+    if (!std::filesystem::copy_file(src_path, dest_path, error)) {
       return env->ThrowStdErrException(error, "cp", *dest);
     }
   } else {
@@ -3446,7 +3449,7 @@ static void CpSyncOverrideFile(const FunctionCallbackInfo<Value>& args) {
   }
 
   if (preserve_timestamps) {
-    CopyUtimes(*src, *dest, env);
+    CopyUtimes(src_path, dest_path, env);
   }
 }
 
@@ -3489,8 +3492,11 @@ static void CpSyncCopyDir(const FunctionCallbackInfo<Value>& args) {
   bool verbatim_symlinks = args[5]->IsTrue();
   bool preserve_timestamps = args[6]->IsTrue();
 
+  auto src_path = src.ToPath();
+  auto dest_path = dest.ToPath();
+
   std::error_code error;
-  std::filesystem::create_directories(*dest, error);
+  std::filesystem::create_directories(dest_path, error);
   if (error) {
     return env->ThrowStdErrException(error, "cp", *dest);
   }
@@ -3632,7 +3638,7 @@ static void CpSyncCopyDir(const FunctionCallbackInfo<Value>& args) {
     return true;
   };
 
-  copy_dir_contents(std::filesystem::path(*src), std::filesystem::path(*dest));
+  copy_dir_contents(src_path, dest_path);
 }
 
 BindingData::FilePathIsFileReturnType BindingData::FilePathIsFile(

test/parallel/test-fs-cp-sync-unicode-dest.mjs

@@ -0,0 +1,23 @@
+// Regression test for https://github.com/nodejs/node/issues/61878
+// fs.cpSync should copy files when destination path has UTF characters.
+import '../common/index.mjs';
+import { cpSync, mkdirSync, readdirSync, readFileSync, writeFileSync } from 'node:fs';
+import { join } from 'node:path';
+import assert from 'node:assert';
+import tmpdir from '../common/tmpdir.js';
+
+tmpdir.refresh();
+
+const src = join(tmpdir.path, 'src');
+mkdirSync(join(src, 'subdir'), { recursive: true });
+writeFileSync(join(src, 'file1.txt'), 'Hello World');
+writeFileSync(join(src, 'subdir', 'nested.txt'), 'Nested File');
+
+const dest = join(tmpdir.path, 'Eyjafjallajökull-Pranckevičius');
+cpSync(src, dest, { recursive: true, force: true });
+
+const destFiles = readdirSync(dest);
+assert.ok(destFiles.includes('file1.txt'));
+assert.strictEqual(readFileSync(join(dest, 'file1.txt'), 'utf8'), 'Hello World');
+assert.ok(destFiles.includes('subdir'));
+assert.strictEqual(readFileSync(join(dest, 'subdir', 'nested.txt'), 'utf8'), 'Nested File');