javascript - Is it OK to use async/await almost everywhere?

Question

I'm currently writing small NodeJS CLI tool for personal usage and I've decided to try ES7 async/await feature with Babel.

It's a network tool so I obviously have asynchronous network requests. I wrote a simple wrapper for request package:

export default function(options) {
    return new Promise(function(resolve, reject) {
        request({...options,
            followAllRedirects: true,
            headers: {
                "user-agent": "Mozilla/5.0 (Windows NT 10.0; WOW64; rv:47.0) Gecko/20100101 Firefox/47.0"
            }
        }, (error, response, body) => {
            if(error) {
                return reject(error);
            }
            resolve({response: response, body: body});
        });
    });
}

Now I can do something like

async function getGooglePage() {
    try {
        var r = await request({url: "http://google.com"});

        console.log(r.body);
        console.log("This will be printed in the end.")
    } catch(e) {
        console.log(e);
    }
}
getGooglePage();

And now I have a question: I do requests in many places and I have to mark all these functions as async, is it a good practice? I mean that almost every function in my code should be async because I need to await a result from other async functions. That's why I think that I misunderstood async/await concept.

Answer 1

async/await is sometimes called "contagious" or "viral" (or so it has in the C# world), because in order for it to be effective, it needs to be supported all the way down the call chain. Forcing something asynchronous to act synchronous can lead to unintended results, so you should extend it from the original method all the way down to the top level consumer using it. In other words, if you create or use a type that uses it, that type should also implement it, and so on all the way up the chain. So yes, it's expected that you add async to every function that itself relies on it. Just note, however, you should not add preemptively add async to functions that don't actually implement or need it.

Just think: If you use async (by awaiting something, I mean), you are async. Avoid squashing an async call into something synchronous.