What is @google-cloud/promisify?
@google-cloud/promisify is a utility library that helps convert callback-based functions to promise-based functions. This is particularly useful for modern JavaScript development where promises and async/await syntax are preferred over traditional callback patterns.
What are @google-cloud/promisify's main functionalities?
Promisify a single function
This feature allows you to convert a single callback-based function to a promise-based function. The code sample demonstrates how to use the `promisify` function to convert a traditional callback function into one that returns a promise.
const {promisify} = require('@google-cloud/promisify');
function callbackFunction(arg1, arg2, callback) {
// Simulate an asynchronous operation
setTimeout(() => {
callback(null, 'result');
}, 1000);
}
const promiseFunction = promisify(callbackFunction);
promiseFunction('arg1', 'arg2').then(result => {
console.log(result); // 'result'
}).catch(err => {
console.error(err);
});
Promisify all functions in an object
This feature allows you to promisify all functions in an object. The code sample demonstrates how to use the `promisifyAll` function to convert all callback-based functions in an object to promise-based functions, appending 'Async' to the function names.
const {promisifyAll} = require('@google-cloud/promisify');
const obj = {
callbackFunction(arg1, arg2, callback) {
setTimeout(() => {
callback(null, 'result');
}, 1000);
}
};
promisifyAll(obj);
obj.callbackFunctionAsync('arg1', 'arg2').then(result => {
console.log(result); // 'result'
}).catch(err => {
console.error(err);
});
Other packages similar to @google-cloud/promisify
util.promisify
The `util.promisify` function is a built-in Node.js utility that converts callback-based functions to promise-based functions. It is similar to @google-cloud/promisify but is part of the Node.js standard library, making it a more straightforward choice for many developers.
bluebird
Bluebird is a fully-featured promise library that includes a `promisify` function to convert callback-based functions to promise-based ones. It offers more features and better performance compared to @google-cloud/promisify, but it is a larger library and may be overkill for simple use cases.
pify
Pify is a lightweight library that provides a simple way to promisify callback-based functions. It is similar to @google-cloud/promisify but is more minimalistic and has fewer dependencies, making it a good choice for smaller projects.
@google-cloud/promisify
A simple utility for promisifying functions and classes.
Google Cloud Common node.js module contains stuff used by other Cloud API modules.
Read more about the client libraries for Cloud APIs, including the older
Google APIs Client Libraries, in Client Libraries Explained.
Installing the package
It's unlikely you will need to install this package directly, as it will be
installed as a dependency when you install other @google-cloud
packages.
Versioning
This library follows Semantic Versioning.
This library is considered to be in alpha. This means it is still a
work-in-progress and under active development. Any release is subject to
backwards-incompatible changes at any time.
More Information: Google Cloud Platform Launch Stages
Contributing
Contributions welcome! See the Contributing Guide.
License
Apache Version 2.0
See LICENSE