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prologic /
Last active February 18, 2024 15:59
Learn Go in ~5mins
ClickerMonkey / types.ts
Last active February 6, 2024 07:21
Typescript Helper Types
View types.ts
// when T is any|unknown, Y is returned, otherwise N
type IsAnyUnknown<T, Y, N> = unknown extends T ? Y : N;
// when T is never, Y is returned, otherwise N
type IsNever<T, Y = true, N = false> = [T] extends [never] ? Y : N;
// when T is a tuple, Y is returned, otherwise N
// valid tuples = [string], [string, boolean],
// invalid tuples = [], string[], (string | number)[]

Logic composability problems of lifecycle hooks in React

Suppose I have these components in my project:

class MessageHeader extends React.Component { /* ... */ }

class NiceButton extends React.Component { /* ... */ }

class FridgeContents extends React.Component { /* ... */ }
Rich-Harris /
Last active February 21, 2024 13:48
Stuff I wish I'd known sooner about service workers

Stuff I wish I'd known sooner about service workers

I recently had several days of extremely frustrating experiences with service workers. Here are a few things I've since learned which would have made my life much easier but which isn't particularly obvious from most of the blog posts and videos I've seen.

I'll add to this list over time – suggested additions welcome in the comments or via

Use Canary for development instead of Chrome stable

Chrome 51 has some pretty wild behaviour related to console.log in service workers. Canary doesn't, and it has a load of really good service worker related stuff in devtools.

deanrad /
Last active December 27, 2020 18:31
TL;DR Better Redux involves using maps of action types to reducers, not switch/case statements

Distilling the Essence of Reducers

Redux has brought the notion of reducer back into the awareness of many developers for whom they are a novel concept. In fact they are quite simple, and used all the time in such things as SUM aggregations in databases, where they compute a single value from many.

It's great that Redux has made reducers known to a broader audience, though they are relatively ancient concepts in programming, in fact. But the particular way Redux illustrates a reducer in its documentaion is, in my opinion, with a coding style that is harder to extend and read than it should be. Let's distill reducers down to their essensce, and build up Redux reducers in a way that lowers complexity, and helps separate Redux idioms from your business logic.

The simplest reducer

A reducer is a pure function that accepts more arguments than it returns. That is to say - one whose "arity" is greater than 1. It 'reduces' the two things you pass it down to a single value. Here are two reducers, in a map

RReverser / better-console-log.js
Last active May 9, 2019 21:07
Better console.log in Node
View better-console-log.js
// UPD:
// Now available as npm module!
// Check out for details.
console.log = (function (log, inspect) {
return function () {
return log.apply(this,, function (arg) {
return inspect(arg, { depth: 1, colors: true });
View gist:598fa75e22bdfa44cf47

2015-01-29 Unofficial Relay FAQ

Compilation of questions and answers about Relay from React.js Conf.

Disclaimer: I work on Relay at Facebook. Relay is a complex system on which we're iterating aggressively. I'll do my best here to provide accurate, useful answers, but the details are subject to change. I may also be wrong. Feedback and additional questions are welcome.

What is Relay?

Relay is a new framework from Facebook that provides data-fetching functionality for React applications. It was announced at React.js Conf (January 2015).

staltz /
Last active February 28, 2024 15:18
The introduction to Reactive Programming you've been missing
tsiege / The Technical Interview Cheat
Last active February 24, 2024 15:52
This is my technical interview cheat sheet. Feel free to fork it or do whatever you want with it. PLEASE let me know if there are any errors or if anything crucial is missing. I will add more links soon.
View The Technical Interview Cheat


I have moved this over to the Tech Interview Cheat Sheet Repo and has been expanded and even has code challenges you can run and practice against!