await is not a no-op. If the awaited thing is not a promise, it is wrapped in a promise, that promise is awaited. Therefore await changes the execution order (but you should not rely on it nevertheless): console.log(1); (async function() { var x = await 5; // remove await to see 1,3,2 console.log(3); })(); console.log(2); … Read more
You’re quite correct that changing target is the wrong approach and changing lib is the correct approach, however you have specified the wrong version of the language. According to MDN, Object.entries was officially added in the ES2017 specification. “lib”: [“es2017”] is therefore what you must specify instead*. If you wish to add only the declarations … Read more
async/await only works with promises, not with streams. There are ideas to make an extra stream-like data type that would get its own syntax, but those are highly experimental if at all and I won’t go into details. Anyway, your callback is only waiting for the end of the stream, which is a perfect fit … Read more
It seems to be best practice not to place multiple lines of business logic in the try body Actually I’d say it is. You usually want to catch all exceptions from working with the value: try { const createdUser = await this.User.create(userInfo); console.log(createdUser) // business logic goes here } catch (error) { console.error(error) // from … Read more
async/await is not magic. An async function is a function that can unwrap Promises for you, so you’ll need api.on() to return a Promise for that to work. Something like this: function apiOn(event) { return new Promise(resolve => { api.on(event, response => resolve(response)); }); } Then async function test() { return await apiOn( ‘someEvent’ ); … Read more
Alternatives An alternative to this: async function main() { try { var quote = await getQuote(); console.log(quote); } catch (error) { console.error(error); } } would be something like this, using promises explicitly: function main() { getQuote().then((quote) => { console.log(quote); }).catch((error) => { console.error(error); }); } or something like this, using continuation passing style: function main() … Read more
I can’t seem to wrap my head around why this does not work. Because main returns a promise; all async functions do. At the top level, you must either: Use top-level await (proposal, MDN; ES2022, broadly supported in modern environments) that allows top-level use of await in a module. or Use a top-level async function … Read more
The problem here is that you are trying to await an array of promises rather than a Promise. This doesn’t do what you expect. When the object passed to await is not a Promise, await simply returns the value as-is immediately instead of trying to resolve it. So since you passed await an array (of … Read more
Your best bet is to throw an Error wrapping the value, which results in a rejected promise with an Error wrapping the value: } catch (error) { throw new Error(400); } You can also just throw the value, but then there’s no stack trace information: } catch (error) { throw 400; } Alternately, return a … Read more
Your sleep function does not work because setTimeout does not (yet?) return a promise that could be awaited. You will need to promisify it manually: function timeout(ms) { return new Promise(resolve => setTimeout(resolve, ms)); } async function sleep(fn, …args) { await timeout(3000); return fn(…args); } Btw, to slow down your loop you probably don’t want … Read more