!Build Status

es6-promisify

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

Install

Install with npm

``bash
npm install es6-promisify
`

Example

`js
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

`js
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

`js
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

`js
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
`

$3

Test with tape

`bash
$ npm test
``

Published under the MIT License.