chrome.runtime.onMessage response with async await

Question

I want to use async await in an onMessage listener:

chrome.runtime.onMessage.addListener(async (request, sender, sendResponse) =>{
    var key = await getKey(         


        

Answer 1

Honestly, it looks like Google Chrome Extensions don't support the await keyword. I've successfully used asynchronous chrome.runtime.onMessage.addListener's before, and every time I try to use await I see this syntax error in the Chrome Debugging Tools, on the line that I use await:

Here's how I've been testing:

I created a very basic listener:

chrome.runtime.onMessage.addListener(function(data, MessageSender, sendResponse) {
    sendResponse(awaitTester);
    var async = true;

    // returns true if asyncronous is needed
    if (async) return true;
});

my awaitTester function looks like this:

function awaitTester() {
    var prom = new Promise(function(resolve, reject) {
        setTimeout(function() {
            resolve('test');
        }, 4000);
    });

    var awaited = await prom;
    return awaited;
}

finally, my message sender is what you'd expect:

chrome.runtime.sendMessage({}, function(message) {
    debugger;
    console.log(message);
});

And in the debugger / console I always get undefined.