how to use node await syntax with web3 version 1.x

Question

I am trying to use node await syntax but keep getting errors. I run

web3 = new Web3(new Web3.providers.HttpProvider('https://mainnet.infura.io'));
let isListening = await web3.eth.net.isListening();
    let numPeers = await web3.eth.net.getPeerCount();
    console.log( "node " + infuraUrl + " listening: " + isListening.toString() + " with " + numPeers + " peers");

and I keep getting this error:

let isListening = await web3.eth.net.isListening();
                        ^^^^

SyntaxError: Unexpected identifier
    at createScript (vm.js:80:10)
    at Object.runInThisContext (vm.js:139:10)
    at Module._compile (module.js:607:28)
    at Object.Module._extensions..js (module.js:654:10)
    at Module.load (module.js:556:32)
    at tryModuleLoad (module.js:499:12)
    at Function.Module._load (module.js:491:3)
    at Function.Module.runMain (module.js:684:10)
    at startup (bootstrap_node.js:187:16)
    at bootstrap_node.js:608:3

Answer 1

first verify you are using web3 version 1.x which supports promise.

web3 = new Web3(new Web3.providers.HttpProvider(infuraUrl));
console.log("web 3 version " + web3.version);

if u don't have 1.x version. refer to this question

syntax is correct but when using await, it must be placed inside an async function as such:

async function logMetaData(){
    let isListening = await web3.eth.net.isListening();
    let numPeers = await web3.eth.net.getPeerCount();
    console.log( "node " + infuraUrl + " listening: " + isListening.toString() + " with " + numPeers + " peers");
};

and then just call this, and your done.

logMetaData();