7.0.0 • Published 3 years ago
es6-promisify v7.0.0
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.