TypeScript Enum Exhausitive

fiddle for https://stackoverflow.com/questions/39419170/how-do-i-check-that-a-switch-block-is-exhaustive-in-typescript

by tmtron

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

enum Color {
    Red,
    Green,
    Blue
}

function getColorName(c: Color): string {
    switch(c) {
        case Color.Red:
            return 'red';
        case Color.Green:
            return 'green';
        // Forgot about Blue
    }
}

const val = getColorName(Color.Red));
const val = getColorName('abc' as Color));

document.querySelector("#app").innerHTML = val;