gragland

import { useRef, useEffect, useCallback } from 'react';

// Usage
function App(){
  // State for storing mouse coordinates
  const [coords, setCoords] = useState({ x: 0, y: 0 });
  
  // Event handler utilizing useCallback ...
  // ... so that reference never changes.
  const handler = useCallback(

gragland

// Current auth status
let currentAuth = false;

// Holds setAuth for every instance of hook
const authSetters = new Set();

function useFakeAuth() {
  // Auth state and setter
  const [auth, setAuth] = useState(currentAuth);

gragland

import { useState, useEffect, useRef } from 'react';

// Let's pretend this <Counter> component is expensive to re-render so ...
// ... we wrap with React.memo, but we're still seeing performance issues :/
// So we add useWhyDidYouUpdate and check our console to see what's going on.
const Counter = React.memo(props => {
  useWhyDidYouUpdate('Counter', props);
  return <div style={props.style}>{props.count}</div>;
});

gragland

import { useState, useEffect, useRef } from 'react';

// Let's pretend this <Counter> component is expensive to re-render so ...
// ... we wrap with React.memo, but we're still seeing performance issues :/
// So we add useWhyDidYouUpdate and check our console to see what's going on.
const Counter = React.memo(props => {
  useWhyDidYouUpdate('Counter', props);
  return <div style={props.style}>{props.count}</div>;
});

gragland

// Usage
function App() {
  const [darkMode, setDarkMode] = useDarkMode();

  return (
    <div>
      <div className="navbar">
        <Toggle darkMode={darkMode} setDarkMode={setDarkMode} />
      </div>
      <Content />

gragland

import { useState, useEffect } from 'react';

function App() {
  const columnCount = useMedia(
    // Media queries
    ['(min-width: 1500px)', '(min-width: 1000px)', '(min-width: 600px)'],
    // Column counts (relates to above media queries by array index)
    [5, 4, 3],
    // Default column count
    2

gragland

import { useState, useLayoutEffect } from 'react';

// Usage
function App(){
  // State for our modal
  const [modalOpen, setModalOpen] = useState(false);
  
  return (
    <div>
      <button onClick={() => setModalOpen(true)}>Show Modal</button>

gragland

import { useLayoutEffect } from 'react';
import './styles.scss'; // -> https://codesandbox.io/s/15mko9187

// Usage
const theme = {
  'button-padding': '16px',
  'button-font-size': '14px',
  'button-border-radius': '4px',
  'button-border': 'none',
  'button-color': '#FFF',

gragland

import { useState, useRef } from 'react';
import { useSpring, animated } from 'react-spring';

// Displays a row of cards
// Usage of hook is within <Card> component below
function App() {
  return (
    <div className="container">
      <div className="row">
        {cards.map((card, i) => (

gragland

import { useReducer, useCallback } from 'react';

// Usage
function App() {
  const { state, set, undo, redo, clear, canUndo, canRedo } = useHistory({});

  return (
    <div className="container">
      <div className="controls">
        <div className="title">👩‍🎨 Click squares to draw</div>