babel 6 async / await: Unexpected token

Question

Im having trouble getting async / await transforms working. What am I missing?

My .babelrc:

{
  \"presets\": [ \"es2015\", \"stage-0\" ]
}

Answer 1

According to this post you need to have babel-polyfill

Babel 6 regeneratorRuntime is not defined with async/await

Hopefully it'll help you :)

EDIT:

It doesn't have to be babel-polyfill but it's the only one I used.

As Gothdo said: the await keyword has to be in a function scope. Moreover, this function definition has to have the async keyword.

This means that you can not have the await keyword on the top-level scope.

Answer 2

Looks like async/await is only available in babel-preset-stage-3

http://babeljs.io/docs/plugins/preset-stage-3/

Answer 3

You can compile them yourself using the transform-async-to-module-method plugin, this allows you to compile them down to bluebird co-routines which requires ES6 generators (available in node4).

Or if you need to compile it back to ES5 so it's compatible for browsers you can use transform-async-to-generator and facebook's regenerator.

I've written about how to set up your babel config here http://madole.xyz/async-await-es7/

Answer 4

It's recommended to upgrade to Babel 7 and use babel-env as opposed to stages (see here: https://github.com/babel/babel-upgrade).

There's a command you can use to upgrade accordingly:

npx babel-upgrade

Answer 5

Use the Async to generator transform.

Installation

$ npm install babel-plugin-transform-async-to-generator

Usage

Add the following line to your .babelrc file:

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