test: add fs/promises filehandle stat test

Added test for fs/promises filehandle stat.

PR-URL: #20492
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

test/parallel/test-fs-promises-file-handle-stat.js

@@ -0,0 +1,24 @@
+'use strict';
+
+const common = require('../common');
+
+// The following tests validate base functionality for the fs/promises
+// FileHandle.stat method.
+
+const { open } = require('fs/promises');
+const path = require('path');
+const tmpdir = require('../common/tmpdir');
+const assert = require('assert');
+
+tmpdir.refresh();
+common.crashOnUnhandledRejection();
+
+async function validateStat() {
+  const filePath = path.resolve(tmpdir.path, 'tmp-read-file.txt');
+  const fileHandle = await open(filePath, 'w+');
+  const stats = await fileHandle.stat();
+  assert.ok(stats.mtime instanceof Date);
+}
+
+validateStat()
+  .then(common.mustCall());