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I may be slow to respond.

Martin Zlámal mrtnzlml

I may be slow to respond.
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gaearon / Classes.js
Created May 27, 2020
Beneath Classes: Prototypes
View Classes.js
class Spiderman {
lookOut() {
alert('My Spider-Sense is tingling.');
let miles = new Spiderman();
robrichard /
Last active Feb 25, 2020
Relay Compatible `@defer` & `@stream`

Using @defer under an array field will return multiple patches. Patches are unique combinations of label and path

  items {
    ...frag @defer(label: "my-label")
View flow_ts_tests.js
A collection of tests where Flow and TypeScript might have different behavior
Some tests are borrowed from
Some tests now have the same behavior as the new versions of Flow/TS have fixed the bugs and improved type safety
/* 1. Accessing unknown properties on objects */
gaearon /
Last active Nov 26, 2020
useLayoutEffect and server rendering

If you use server rendering, keep in mind that neither useLayoutEffect nor useEffect can run until the JavaScript is downloaded.

You might see a warning if you try to useLayoutEffect on the server. Here's two common ways to fix it.

Option 1: Convert to useEffect

If this effect isn't important for first render (i.e. if the UI still looks valid before it runs), then useEffect instead.

function MyComponent() {
bvaughn /
Last active Nov 26, 2020
How to use profiling in production mode for react-dom
miyaokamarina / conditions.js
Last active Nov 21, 2020
Type-level conditions in Flow
View conditions.js
// Licensed under CC BY 4.0.
type $If<X: boolean, Then, Else = empty> = $Call<
& ((true, Then, Else) => Then)
& ((false, Then, Else) => Else),
sibelius / MutationUtils.js
Created Mar 19, 2018
Helper methods for Relay Modern updater
View MutationUtils.js
// @flow
import { ConnectionHandler } from 'relay-runtime';
import { isObject, isArray } from 'lodash/fp';
export function listRecordRemoveUpdater({ parentId, itemId, parentFieldName, store }) {
const parentProxy = store.get(parentId);
const items = parentProxy.getLinkedRecords(parentFieldName);
parentProxy.setLinkedRecords(items.filter(record => record._dataID !== itemId), parentFieldName);
klaaspieter /
Created Jun 22, 2017 — forked from anonymous/
Acronyms Seriously Suck - Elon Musk

From time to time, Musk will send out an e-mail to the entire company to enforce a new policy or let them know about something that's bothering him. One of the more famous e-mails arrived in May 2010 with the subject line: Acronyms Seriously Suck:

There is a creeping tendency to use made up acronyms at SpaceX. Excessive use of made up acronyms is a significant impediment to communication and keeping communication good as we grow is incredibly important. Individually, a few acronyms here and there may not seem so bad, but if a thousand people are making these up, over time the result will be a huge glossary that we have to issue to new employees. No one can actually remember all these acronyms and people don't want to seem dumb in a meeting, so they just sit there in ignorance. This is particularly tough on new employees.

That needs to stop immediately or I will take drastic action - I have given enough warning over the years. Unless an acronym is approved by me, it should not enter the SpaceX glossary.

gaearon / slim-redux.js
Last active Nov 14, 2020
Redux without the sanity checks in a single file. Don't use this, use normal Redux. :-)
View slim-redux.js
function mapValues(obj, fn) {
return Object.keys(obj).reduce((result, key) => {
result[key] = fn(obj[key], key);
return result;
}, {});
function pick(obj, fn) {
return Object.keys(obj).reduce((result, key) => {
if (fn(obj[key])) {
View Makefile
# Hello, and welcome to makefile basics.
# You will learn why `make` is so great, and why, despite its "weird" syntax,
# it is actually a highly expressive, efficient, and powerful way to build
# programs.
# Once you're done here, go to
# to learn SOOOO much more.
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