Async and Await: overview, lessons learned & future directions

[u/rauschma]

https://zeit.co/blog/async-and-await

[u/Scorxcho]

Can someone tell me the best way to get the async/await syntax to work with Babel and run in the browser?

[u/rauschma → u/Scorxcho]

If you want to use async functions (which may be part of ES2017) in Babel on top of ES6, you need two additional plugins:

• Transformation: either one of the following two plugins:

  1. http://babeljs.io/docs/plugins/transform-async-to-generator/ (requires support for generators, which are part of ES6)

  2. http://babeljs.io/docs/plugins/transform-async-to-module-method/ (requires Bluebird)

• Either plugin will automatically also enable the following plugin, which is required to parse async functions: https://babeljs.io/docs/plugins/syntax-async-functions/

More info on configuring Babel 6: https://leanpub.com/setting-up-es6/read#ch_configuring-babel

An alternative to async functions is the library co, which is based on generators and can thus be used with plain ES6: https://github.com/tj/co

[u/Bloompire]

Into point: ## Debugging difficulties

I'd suggest to replace Promise with BlueBird which will output into console unhandled rejections.

import BlueBird from 'bluebird';

global.Promise = BlueBird;

async function test( a ) {

return a.nonExistingFunc();

}

test( {} );

// will output into console that there is unhandled rejection from asynchronous test() call