fs,win: fix readdir for named pipe

src/node_file.cc

@@ -1986,8 +1986,26 @@ static void ReadDir(const FunctionCallbackInfo<Value>& args) {
 
   BufferValue path(isolate, args[0]);
   CHECK_NOT_NULL(*path);
+#ifdef _WIN32
+  bool slashCheck = false;
+  if (path.ToStringView().ends_with("/") ||
+      path.ToStringView().ends_with("\\")) {
+    slashCheck = true;
+  }
+#endif
+
   ToNamespacedPath(env, &path);
 
+#ifdef _WIN32
+  if (slashCheck) {
+    std::string result = path.ToString() + "\\";
+    size_t new_length = result.size();
+    path.AllocateSufficientStorage(new_length + 1);
+    path.SetLength(new_length);
+    memcpy(path.out(), result.c_str(), result.size() + 1);
+  }
+#endif
+
   const enum encoding encoding = ParseEncoding(isolate, args[1], UTF8);
 
   bool with_types = args[2]->IsTrue();

test/parallel/test-fs-readdir-pipe.js

@@ -0,0 +1,21 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+const { readdir, readdirSync } = require('fs');
+
+if (!common.isWindows) {
+  common.skip('This test is specific to Windows to test enumerate pipes');
+}
+
+// Ref: https://github.com/nodejs/node/issues/56002
+// This test is specific to Windows.
+
+const pipe = '\\\\.\\pipe\\';
+
+assert.ok(readdirSync(pipe).length >= 0);
+
+readdir(pipe, common.mustCall((err, files) => {
+  assert.ok(err == null);
+  assert.ok(files.length >= 0);
+}));