SyntaxError: Unexpected token function - Async Await Nodejs

bozzmob picture bozzmob · Jun 14, 2016 · Viewed 176.9k times · Source

I was experimenting on using Node version 6.2.1 with some of my code. Had plans to migrate most of the hyper-callback oriented codes to something that looks cleaner and maybe performs better.

I have no clue why, the terminal throws up an error when I try to execute the node code.

helloz.js

(async function testingAsyncAwait() {
    await console.log("Print me!");
})();

Logs-

BOZZMOB-M-T0HZ:rest bozzmob$ node helloz.js 
/Users/bozzmob/Documents/work/nextgennms/rest/helloz.js:1
(function (exports, require, module, __filename, __dirname) { (async function testingAsyncAwait() {
                                                                     ^^^^^^^^
SyntaxError: Unexpected token function
    at Object.exports.runInThisContext (vm.js:53:16)
    at Module._compile (module.js:513:28)
    at Object.Module._extensions..js (module.js:550:10)
    at Module.load (module.js:458:32)
    at tryModuleLoad (module.js:417:12)
    at Function.Module._load (module.js:409:3)
    at Function.Module.runMain (module.js:575:10)
    at startup (node.js:160:18)
    at node.js:456:3
BOZZMOB-M-T0HZ:rest bozzmob$ node -v
v6.2.1

What am I missing? Please throw me some light on the same.


Update 1:

I tried to use Babel as Quentin suggested, But, I am getting the following error still.

Updated Code-

require("babel-core/register");
require("babel-polyfill");

    (async function testingAsyncAwait() {
        await console.log("Print me!");
    })();

Logs-

BOZZMOB-M-T0HZ:rest bozzmob$ babel helloz.js > helloz.trans.js
SyntaxError: helloz.js: Unexpected token (3:7)
  1 | require("babel-polyfill");
  2 | 
> 3 | (async function testingAsyncAwait() {
    |        ^
  4 |     await console.log("Print me!");
  5 | })();

Answer

Quentin picture Quentin · Jun 14, 2016

Async functions are not supported by Node versions older than version 7.6.

You'll need to transpile your code (e.g. using Babel) to a version of JS that Node understands if you are using an older version.

That said, the current (2018) LTS version of Node.js is 8.x, so if you are using an earlier version you should very strongly consider upgrading.