babel-plugin-fast-async

6.1.2 verified Sat Apr 25 auth: no javascript

A Babel v6 plugin that transforms ES7 async/await syntax using fast synchronous transformation instead of generators/regenerator, achieving 3-4x performance improvements in browsers and Node, and up to 10x on mobile. Currently at v6.2.1, it uses the nodent library for compilation and supports options like Promise-based output, generator fallback, and runtime module imports. Requires nodent runtime unless using 'spec' mode with noRuntime. Released under MIT.

Common errors

error Module not found: Can't resolve 'nodent' ↓

cause nodent is a peer dependency but not installed.

fix

Run 'npm install nodent --save' alongside fast-async.

error SyntaxError: Unexpected token function ↓

cause Babel v7+ does not support fast-async; use built-in plugins.

fix

Use @babel/plugin-transform-async-to-generator instead of fast-async.

error TypeError: Cannot assign to read only property 'exports' of object '#<Object>' ↓

cause Mixing ESM and CJS in compiled code; runtime conflict.

fix

Ensure consistent module system; set Babel sourceType appropriately.

Warnings

breaking Babel v6 only; does not support Babel v7+. ↓

fix Upgrade to Babel v7 and use @babel/plugin-transform-async-to-generator or similar.

gotcha Runtime must be included manually for multi-file projects. Set runtimePattern for single include. ↓

fix Set 'runtimePattern' option to a regex matching one file, or use 'useRuntimeModule' for import.

gotcha Stack trace mapping disabled by default (dontMapStackTraces: true) as of v6.1.x. ↓

fix Set 'dontMapStackTraces: false' in env options if you need mapped stack traces.

Install

npm install babel-plugin-fast-async

yarn add babel-plugin-fast-async

pnpm add babel-plugin-fast-async

Imports

plugin
wrong
```
import fastAsync from 'fast-async'
```
correct
```
// .babelrc
{
  "plugins": ["fast-async"]
}
```
This is a Babel plugin, not a runtime import. Use in Babel configuration (JSON, JS, etc.)
default
wrong
```
const fastAsync = require('fast-async')
```
correct
```
// No JavaScript import required; plugin applied via Babel config
```
fast-async is not designed for direct JavaScript require/import. Only use in Babel configuration.

PluginFactory

wrong

import { fastAsync } from 'fast-async'

correct

// Programmatic Babel usage:
const fastAsync = require('fast-async');
babel.transform(code, { plugins: [fastAsync] });

When used programmatically, require the module as a function. Named export does not exist.

Quickstart

Minimal .babelrc to enable fast-async plugin for async/await transformation.

{
  "plugins": ["fast-async"]
}