Can anyone please explain this part of the airbnb style guide to me?
https://github.com/airbnb/javascript#arrays--mapping
It says:
4.6 Use Array.from instead of spread ... for mapping over iterables, because it avoids creating an intermediate array.
// bad
const baz = [...foo].map(bar);
// good
const baz = Array.from(foo, bar);But I don't understand why you wouldn't instead do:
const baz = foo.map(bar);
I think I might understand it now. If it's already an array,
foo.map(bar) is fine. If it's a non-array iterable, then use Array.from to prevent converting to an array just to use map
Is this still accurate?: https://github.com/airbnb/javascript#generators--nope
11.2 Don’t use generators for now.
Why? They don’t transpile well to ES5.
generators transpile to need regenerator-runtime
which is slow and heavyweight
(and there's not many real use cases for generators anyways ime)
Are there plans for the
https://github.com/airbnb/javascript/tree/master/react#class-vs-reactcreateclass-vs-stateless
React portion of the guide to be updated further? Given the way it refers to function components as stateless and only recommending them if you don't have state or refs, I feel like it hasn't been updated to reflect the introduction of hookshttps://github.com/airbnb/javascript/tree/master/react#class-vs-reactcreateclass-vs-stateless
Hi there
I have an async function which I would like to convert to an Observable stream (using rxjs operators). The await calls must execute in the order they appear in the function.
async authenticateUser(profile: Profile): Promise<any> {
let authCookie: any;
try {
authCookie = await getCookie();
} catch (error) {
console.error(error);
}
if (!authCookie || authCookie?.length < 1) {
cancelAuthenticationCookieGet();
throw {message: "login failed", status: -2};
}
await saveProfileAsync(profile);
await storeCurrentAuthCookieAsync(authCookie);
storeSessionStorage();
await setPartitionSessionCookie(profile.url, authCookie);
}Is there a clean way to accomplish the above?
I have one JavaScript specific question
If we have an array of 5 numbers, and the task is to pack their binary values into a single integer
How to do that , any solution for that?
Do you have an idea how to solve that ?
are they all of fixed width?
I saw that you are contributor
description is :
Enzyme is a JavaScript Testing utility for React that makes it easier to test your React Components' output. You can also manipulate, traverse, and in some ways simulate runtime given the output.
Why we can't do that with just
jest
too many yarn or npm packages can lead to enormous bundle size
and bundle size is irrelevant for tests
But I have one issue, because I created app with
yarn create react-app ... and by default I got setupTests.js file with import '@testing-library/jest-dom/extend-expect';
I deleted all three default
@testing-library... packages
I am not sure how to set up
setupTests.js file according to the enzyme test runner instead of default @testing-library...
any advice will be appreciate
enzyme's repo has docs with a jest setup guide
Is there a way to write dynamic form in play(scala) without using React(or teah like that) just use normal html and js (if possible not use
@helper)? For example, a form to let user write setting for servers, we don' t know how many settings they will make so we use a Form(serversetting:List[ServerSetting]) serversetting->list(mapping(id->number,purpose->Text)(ServerSetting.apply)(ServerSetting.unapply)) data structure. In this case, what is the best way to write the html code?
