1 files changed, 35 insertions, 4 deletions

diff --git a/cli/tests/unit_node/_fs/_fs_handle_test.ts b/cli/tests/unit_node/_fs/_fs_handle_test.ts
index 2865fc785..8cfbf6490 100644
--- a/cli/tests/unit_node/_fs/_fs_handle_test.ts
+++ b/cli/tests/unit_node/_fs/_fs_handle_test.ts
@@ -1,21 +1,22 @@
 // Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
 import * as path from "../../../../test_util/std/path/mod.ts";
+import { Buffer } from "node:buffer";
 import * as fs from "node:fs/promises";
 import {
   assert,
   assertEquals,
 } from "../../../../test_util/std/testing/asserts.ts";
-import { Buffer } from "node:buffer";
 
 const moduleDir = path.dirname(path.fromFileUrl(import.meta.url));
 const testData = path.resolve(moduleDir, "testdata", "hello.txt");
+const decoder = new TextDecoder();
 
 Deno.test("readFileSuccess", async function () {
   const fileHandle = await fs.open(testData);
   const data = await fileHandle.readFile();
 
   assert(data instanceof Uint8Array);
-  assertEquals(new TextDecoder().decode(data as Uint8Array), "hello world");
+  assertEquals(decoder.decode(data as Uint8Array), "hello world");
 
   await fileHandle.close();
 });
@@ -27,7 +28,7 @@ Deno.test("read", async function () {
   const buf = new Buffer(byteLength);
   await fileHandle.read(buf, 0, byteLength, 0);
 
-  assertEquals(new TextDecoder().decode(buf as Uint8Array), "hello world");
+  assertEquals(decoder.decode(buf as Uint8Array), "hello world");
 
   await fileHandle.close();
 });
@@ -54,7 +55,37 @@ Deno.test("read specify opt", async function () {
   res = await fileHandle.read(opt2);
 
   assertEquals(res.bytesRead, byteLength);
-  assertEquals(new TextDecoder().decode(res.buffer as Uint8Array), "hello");
+  assertEquals(decoder.decode(res.buffer as Uint8Array), "hello");
+
+  await fileHandle.close();
+});
+
+Deno.test("[node/fs filehandle.write] Write from Buffer", async function () {
+  const tempFile: string = await Deno.makeTempFile();
+  const fileHandle = await fs.open(tempFile, "a+");
+
+  const buffer = Buffer.from("hello world");
+  const res = await fileHandle.write(buffer, 0, 5, 0);
 
+  const data = Deno.readFileSync(tempFile);
+  await Deno.remove(tempFile);
   await fileHandle.close();
+
+  assertEquals(res.bytesWritten, 5);
+  assertEquals(decoder.decode(data), "hello");
+});
+
+Deno.test("[node/fs filehandle.write] Write from string", async function () {
+  const tempFile: string = await Deno.makeTempFile();
+  const fileHandle = await fs.open(tempFile, "a+");
+
+  const str = "hello world";
+  const res = await fileHandle.write(str);
+
+  const data = Deno.readFileSync(tempFile);
+  await Deno.remove(tempFile);
+  await fileHandle.close();
+
+  assertEquals(res.bytesWritten, 11);
+  assertEquals(decoder.decode(data), "hello world");
 });