Is this ‘a thing’? Yes. It comes up every now and then, e.g. here. They’re known as IIAFEs 🙂 If you want to put focus on the arrow, you could also call them IIAAFs. Are there pitfalls here I should be aware of? Whenever you call a promise-returning function and don’t return the result to … Read more
Browser vendors don’t implement specific versions, but specific features. Almost every modern browser is still missing features from ES2017-ES2020. Hence there is not and won’t be a table where you can see an ES version to browser version mapping. But that is not a problem because you as a developer do the same. You use … Read more
There are two places I check whenever I have questions such as this: The Can I Use website: http://caniuse.com/#search=await And Node Green: http://node.green/#async-functions Typically an answer is encouraged to include the relevant information to avoid link rot. But ironically this answer has exactly the opposite problem: this answer will rot (the information below will become … Read more
If you’re using async/await, all your calls have to use Promises or async/await. You can’t just magically get an async result from a sync call. Your final call needs to be: getResult().then(response => console.log(response)); Or something like: (async () => console.log(await getResult()))()
await p schedules execution of the rest of your function when promise p resolves. That’s all. async lets you use await. That’s (almost) all it does (It also wraps your result in a promise). Together they make non-blocking code read like simpler blocking code. They don’t unblock code. For a responsive UI, offload CPU-intensive work … Read more
Every async function returns a Promise object. The await statement operates on a Promise, waiting until the Promise resolves or rejects. So no, you can’t do console.log on the result of an async function directly, even if you use await. Using await will make your function wait and then return a Promise which resolves immediately, … Read more
Two issues jump out: Your getData never returns anything, so its promise (async functions always return a promise) will be fulfilled with undefined if it doesn’t reject The error message clearly shows you’re trying to directly render the promise getData returns, rather than waiting for it to settle and then rendering the fulfillment value Addressing … Read more
Update: As others have pointed out, this doesn’t really work. @kuboon has a nice workaround in an answer below here.. You can do this class Foo { get bar() { return (async () => { return await someAsyncOperation(); })(); } } which again is the same as class Foo { get bar() { return new … Read more
The Promise approach export default function createUser(params) { const request = axios.post(‘http://www…’, params); return (dispatch) => { function onSuccess(success) { dispatch({ type: CREATE_USER, payload: success }); return success; } function onError(error) { dispatch({ type: ERROR_GENERATED, error }); return error; } request.then(success => onSuccess, error => onError); }; } The async/await approach export default function createUser(params) … Read more
You can’t do this as you imagine, because you can’t use await if it is not directly inside an async function. The sensible thing to do here would be to make the function passed to map asynchronous. This means that map would return an array of promises. We can then use Promise.all to get the … Read more