TypeScript

by b1ncer

HTML

<div id="app"></div>

CSS

body {
  background: #20262E;
  padding: 20px;
  font-family: Helvetica;
}

#app {
  background: #fff;
  border-radius: 4px;
  padding: 20px;
  transition: all 0.2s;
  text-align: center;
}

TypeScript

type o = {
	f: () => void
}

function(a: o | undefined) {
	a.f()
}