fedyk

const request1 = () => new Promise((resolve, reject) => {
  console.log('request1')
  setTimeout(() => {
    console.log('request1-resolved')
    resolve(true)
  }, 1000)
})

const request2 = () => new Promise((resolve, reject) => {
  console.log('request2')

fedyk

class App extends React.Component {

  shouldComponentUpdate(nextProps, nextState) {
    const nextPropsKeys = Object.keys(nextProps);
    const nextStateKeys = Object.keys(nextState);

    for (let i = 0; i < nextPropsKeys.length; i++) {
      const key = nextPropsKeys[i];

      if (nextProps[key] !== this.props[key]) {

fedyk

function RGBAtoRGB(r, g, b, a, r2,g2,b2){
    var r3 = Math.round(((1 - a) * r2) + (a * r))
    var g3 = Math.round(((1 - a) * g2) + (a * g))
    var b3 = Math.round(((1 - a) * b2) + (a * b))
    return "rgb("+r3+","+g3+","+b3+")";
    } 

$("#result").html(RGBAtoRGB(225,110,0,0.5,255,255,255));
​

fedyk

class MyComponent extends React.Component<IProps> {

  shouldComponentUpdate(nextProps, nextState) {
    const nextPropsKeys = Object.keys(nextProps)
    const propsKeys = Object.keys(this.props)

    if (nextPropsKeys.length !== propsKeys.length) {
      console.warn(`[MyComponent]: Mismatch in prop's keys`)
      return true;
    }

fedyk

function freezeApp(duration) {
  var now = new Date().getTime();
  var endTime = now + duration;
  console.log('start freeze time', new Date().toISOString(), 'window is focused:', document.hasFocus());
  while(new Date().getTime() < endTime) document.querySelector('this.is > [very] > *[heavy] > .css[selector]');
  console.log('end freeze time', new Date().toISOString(), 'window is focused:', document.hasFocus());
}

/**
 * Freeze app for 5000ms with 2000ms delay

fedyk

[{
  name: "Dwight Schrute",
  email: "d.schrute@dunder-mifflin.com",
  avatar: "https://i.ibb.co/PYzBDTy/dwight.png"
}, {
  name: "Kevin Malone",
  email: "k.malone@dunder-mifflin.com",
  avatar: "https://i.ibb.co/0n7D37f/kevin.png"
}, {
  name: "Pam Beesly",