// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license. import { write, writeSync } from "node:fs"; import { assertEquals } from "@test_util/std/assert/mod.ts"; import { Buffer } from "node:buffer"; const decoder = new TextDecoder("utf-8"); Deno.test({ name: "Data is written to the file with the correct length", async fn() { const tempFile: string = await Deno.makeTempFile(); using file = await Deno.open(tempFile, { create: true, write: true, read: true, }); const buffer = Buffer.from("hello world"); const bytesWrite = await new Promise((resolve, reject) => { write(file.rid, buffer, 0, 5, (err: unknown, nwritten: number) => { if (err) return reject(err); resolve(nwritten); }); }); const data = await Deno.readFile(tempFile); await Deno.remove(tempFile); assertEquals(bytesWrite, 5); assertEquals(decoder.decode(data), "hello"); }, }); Deno.test({ name: "Data is written synchronously to the file with the correct length", fn() { const tempFile: string = Deno.makeTempFileSync(); using file = Deno.openSync(tempFile, { create: true, write: true, read: true, }); const buffer = Buffer.from("hello world"); const bytesWrite = writeSync(file.rid, buffer, 0, 5); const data = Deno.readFileSync(tempFile); Deno.removeSync(tempFile); assertEquals(bytesWrite, 5); assertEquals(decoder.decode(data), "hello"); }, });