jlongster

3 Gripes With React

I started using React 3.5 years ago, and I still love it. It was such a well-designed solution that not much has changed since then, only superficial stuff like naming. What I learned then is still wholly applicable today because it's such a good idea (although now you can choose from many other libraries). On top of that, we now benefit from an entirely new architecture (fiber) without changing much.

ArVan

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');

var index = require('./routes/index');
var user = require('./routes/user');
var auth = require('./routes/auth');

gaearon

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() {

sophiebits

const {useCallback, useEffect, useReducer, useRef} = require('react');

let effectCapture = null;

exports.useReducerWithEmitEffect = function(reducer, initialArg, init) {
  let updateCounter = useRef(0);
  let wrappedReducer = useCallback(function(oldWrappedState, action) {
    effectCapture = [];
    try {
      let newState = reducer(oldWrappedState.state, action.action);

bvaughn

useSubscription and useMutableSource¹ tearing and deopt behavior.

Mounting a new tree

The tree below represents a React application mounting. During mount, two components read from an external, mutable source. The first one (List) reads version 1 of that data and the second one (Item) reads version 2.

Deopt

useSubscription (legacy mode)

N/A.