babel-plugin-transform-async-to-generator

What is babel-plugin-transform-async-to-generator?

The babel-plugin-transform-async-to-generator package is a Babel plugin that transforms async functions into ES2015 generator functions. This allows for the use of async/await syntax in environments that do not natively support it by converting the code into a form that can be executed by older JavaScript engines.

What are babel-plugin-transform-async-to-generator's main functionalities?

Transform async functions to generator functions

This feature allows you to transform an async function into a generator function. The provided code sample demonstrates how to use the Babel core library along with the babel-plugin-transform-async-to-generator plugin to transform an async function into a generator function.

const babel = require('@babel/core');
const code = `async function fetchData() { await fetch('https://api.example.com/data'); }`;
const output = babel.transform(code, { plugins: ['babel-plugin-transform-async-to-generator'] });
console.log(output.code);

Support for await expressions

This feature ensures that await expressions within async functions are properly transformed into yield expressions within generator functions. The code sample shows how an async function with an await expression is transformed.

const babel = require('@babel/core');
const code = `async function fetchData() { const data = await fetch('https://api.example.com/data'); return data; }`;
const output = babel.transform(code, { plugins: ['babel-plugin-transform-async-to-generator'] });
console.log(output.code);

Other packages similar to babel-plugin-transform-async-to-generator

babel-plugin-transform-async-to-module-method

This Babel plugin transforms async functions to calls to a specified module method. It is useful when you want to use a custom implementation for handling async functions. Unlike babel-plugin-transform-async-to-generator, which converts async functions to generator functions, this plugin allows you to specify a custom method to handle async functions.

babel-plugin-syntax-async-functions

This plugin allows Babel to parse async functions but does not transform them. It is useful if you want to use async functions in your code but handle the transformation with another tool or plugin. In contrast, babel-plugin-transform-async-to-generator both parses and transforms async functions.

babel-plugin-transform-regenerator

This plugin transforms generator functions and async functions using regenerator. It provides a more comprehensive transformation that includes both async and generator functions, whereas babel-plugin-transform-async-to-generator focuses specifically on transforming async functions to generator functions.

README

babel-plugin-transform-async-to-generator

Turn async functions into ES2015 generators

Example

In

async function foo() {
  await bar();
}

Out

var _asyncToGenerator = function (fn) {
  ...
};
var foo = _asyncToGenerator(function* () {
  yield bar();
});

Installation

npm install --save-dev babel-plugin-transform-async-to-generator

Usage

Via .babelrc (Recommended)

.babelrc

{
  "plugins": ["transform-async-to-generator"]
}

Via CLI

babel --plugins transform-async-to-generator script.js

Via Node API

require("babel-core").transform("code", {
  plugins: ["transform-async-to-generator"]
});

References

• Proposal: Async Functions for ECMAScript