Using async/await in node 7.4

Question

I thought async/await was supported in node 7.4, however this example does not work:

const Promise = require('bluebird');

async function main(){
  await Promise.delay(1000)
}

main();

Results in:

async function main(){
      ^^^^^^^^
SyntaxError: Unexpected token function

How can I use async/await with node 7.4?

Possible duplicate of [async await with nodejs 7](http://stackoverflow.com/questions/41347260/async-await-with-nodejs-7) — stdob--, Jan 20 '17 at 06:21

Jyotman Singh · Accepted Answer · 2017-02-22T06:23:37.143

Yes async-await is supported in Node.js v7 but its locked behind the harmony flag. Features which are not yet production ready are behind this flag.

To use async-await in Node.js v7 simply run Node service with this flag -

node --harmony-async-await app.js

The official release of async-await is slated for Node.js v8 which will be launched in April.

You can follow this pull request to check its status. Basically the correct functioning of async-await is dependent on the integration of V8 engine v5.5 into Node.js. Currently Node.js uses V8 v5.4 which is solved by this pull request.

Update 1 - It seems V8 v5.5 might be coming to Node.js v7. Follow this pull request for more details.

Update 2 - Good news guys! Node.js version 7.6.0 now officially supports async functions without using the --harmony flag as V8 engine 5.5 has been successfully ported.

Now you only need to use the --harmony flag if your Node.js version is between 7.0 to 7.5.0 (inclusive). For complete changelog refer here.

score 14 · Answer 2 · answered Feb 22 '17 at 16:03

14

Node.js 7.6.0 released several hours ago and they included v8 5.5. Now you can use async/await without flag.

answered Feb 22 '17 at 16:03

Dmitriy Eroshenko

427
3
10

score 2 · Answer 3 · answered Jan 20 '17 at 06:14

2

You will need harmony flag for this to work.

Try again with node --harmony-async-await myscript.js

answered Jan 20 '17 at 06:14

Tuan Anh Tran

6,807
6
37
54

score 2 · Answer 4 · edited Oct 30 '17 at 14:43

Node version 7.6 now supports async/await out of the box. If you haven’t tried it yet, you should adopt it immediately and never look back.

  const makeRequest = () =>
      getJSON()
        .then(data => {
          console.log(data)
          return "done"
        })

    makeRequest()

And using async/await:

const makeRequest = async () => {
  console.log(await getJSON())
  return "done"
}

makeRequest()

score 0 · Answer 5 · edited Aug 25 '18 at 23:54

0

I had the same issue, what I did is installed asyncawait using below command

npm install asyncawait

afterwards i declared await and async using below command

const async = require('asyncawait/async');
const await = require('asyncawait/await');

then used these where it was required but my commands were within async(my-code) & await(my-code).

And it worked perfectly for me.

edited Aug 25 '18 at 23:54

mischva11

2,811
3
18
34

answered Aug 25 '18 at 19:56

sankalp nayak

11
2

hi and welcome to stackockflow, for an answer please provide more information like why your solution works and what was done wrong. Those answers can be found an google etc. and should be clear for everyone. Thanks for contributing and good luck! – mischva11 Aug 25 '18 at 20:01
Welcome to SO. As mischva11 mentioned, please explain your answer in details. In addition, please follow the SO guidelines while giving an answer. You can read the same here: https://stackoverflow.com/help/how-to-answer – dj079 Aug 25 '18 at 20:27

Using async/await in node 7.4

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