thenify-all

What is thenify-all?

The thenify-all npm package is used to promisify entire modules or specific sets of functions. This means it can convert callback-based functions or methods to return promises instead, allowing for more modern, cleaner asynchronous code using promises or async/await syntax.

What are thenify-all's main functionalities?

Promisifying an entire module

This code sample demonstrates how to promisify all methods of the Node.js 'fs' module. After promisifying, methods like 'readFile' return a promise that can be used with '.then()' and '.catch()' for handling asynchronous operations.

const thenifyAll = require('thenify-all');
const fs = thenifyAll(require('fs'));

fs.readFile('file.txt', 'utf8').then(contents => {
  console.log(contents);
}).catch(error => {
  console.log(error);
});

Promisifying selected functions

This code sample shows how to promisify only selected functions from the 'fs' module. In this case, only 'readFile' and 'writeFile' are promisified, and they can be used with promise syntax.

const thenifyAll = require('thenify-all');
const fs = require('fs');
const promisifiedFs = thenifyAll(fs, {}, ['readFile', 'writeFile']);

promisifiedFs.readFile('file.txt', 'utf8').then(contents => {
  console.log(contents);
}).catch(error => {
  console.log(error);
});

Other packages similar to thenify-all

bluebird

Bluebird is a full-featured promise library with a focus on innovative features and performance. It includes utilities for converting callback-based functions to promises, similar to thenify-all, but also offers a wide range of additional features like cancellation, progress tracking, and more sophisticated error handling.

util.promisify

Util.promisify is a function included in the Node.js standard library that converts a callback-based function into a promise-based one. It is similar to thenify-all in its basic functionality but is built into Node.js and does not require an additional package. It does not, however, promisify entire modules at once.

pify

Pify is a lightweight promise utility that works similarly to thenify-all by converting callback-based functions to promises. It offers a simple API and supports promisifying object methods, but unlike thenify-all, it also allows for options to customize the promisification process, such as setting multiArgs to handle functions that have multiple success parameters.

README

thenify-all

Promisifies all the selected functions in an object.

var thenifyAll = require('thenify-all');

var fs = thenifyAll(require('fs'), {}, [
  'readFile',
  'writeFile',
]);

fs.readFile(__filename).then(function (buffer) {
  console.log(buffer.toString());
});

API

var obj = thenify(source, [obj], [methods])

• source - the source object for the async functions
• obj - the destination to set all the promisified methods
• methods - an array of method names of source