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What is the purpose of the util.promisify function in Node.js?

Q: What is the purpose of the util.promisify function in Node.js?

**TL;DR.** util.promisify converts a classic **error-first callback** function ( (err, result) => … ) into one that **returns a Promise**, so you can await legacy Node APIs instead of nesting callbacks. Many core modules also ship promise versions (e.g. fs/promises ) you can use directly. fn(args, cb) cb(err, result) promisify fn(args) → Pr

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Explain how to convert older callback-style APIs into modern promise-based APIs.

utilitiespromisesasync

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Promisify a callback API

import { promisify } from 'node:util';
import { readFile } from 'node:fs';

const readFileAsync = promisify(readFile);
const text = await readFileAsync('./data.txt', 'utf8');

// Equivalent built-in promise API (preferred):
import { readFile as read } from 'node:fs/promises';
const text2 = await read('./data.txt', 'utf8');

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