es6-promisify

es6-promisify

Converts callback-based functions to Promises, using a boilerplate callback function.

Install

Install with npm

npm install es6-promisify

Example

const {promisify} = require("es6-promisify");

// Convert the stat function
const fs = require("fs");
const stat = promisify(fs.stat);

// Now usable as a promise!
try {
    const stats = await stat("example.txt");
    console.log("Got stats", stats);
} catch (err) {
    console.error("Yikes!", err);
}

Promisify methods

const {promisify} = require("es6-promisify");

// Create a promise-based version of send_command
const redis = require("redis").createClient(6379, "localhost");
const client = promisify(redis.send_command.bind(redis));

// Send commands to redis and get a promise back
try {
    const pong = await client.ping();
    console.log("Got", pong);
} catch (err) {
    console.error("Unexpected error", err);
} finally {
    redis.quit();
}

Handle multiple callback arguments, with named parameters

const {promisify} = require("es6-promisify");

function test(cb) {
    return cb(undefined, 1, 2, 3);
}

// Create promise-based version of test
test[promisify.argumentNames] = ["one", "two", "three"];
const multi = promisify(test);

// Returns named arguments
const result = await multi();
console.log(result); // {one: 1, two: 2, three: 3}

Provide your own Promise implementation

const {promisify} = require("es6-promisify");

// Now uses Bluebird
promisify.Promise = require("bluebird");

const test = promisify(cb => cb(undefined, "test"));
const result = await test();
console.log(result); // "test", resolved using Bluebird

Tests

Test with tape

$ npm test

Published under the MIT License.

Similar packages

Other packages similar to es6-promisify

util.promisify

The `util.promisify` function is a built-in Node.js utility that provides similar functionality to es6-promisify. It converts callback-based functions to return Promises. Since it is built into Node.js, it does not require an additional package installation. However, it is only available in Node.js versions 8.0.0 and above.

bluebird

Bluebird is a fully-featured Promise library that includes a `promisify` method. It offers more advanced features and better performance compared to es6-promisify. Bluebird is a good choice if you need additional Promise utilities and optimizations.

pify

Pify is a lightweight utility that promisifies callback-style functions. It is similar to es6-promisify but offers more customization options, such as filtering which methods to promisify and handling multiple arguments. Pify is a good alternative if you need more control over the promisification process.