// TREE-SHAKING
import { cube } from './maths.js';
console.log(cube(5)); // 125
Skip to content main.js (entry module)
ES6 modules go in...
// maths.js
// This function isn't used anywhere, so
// Rollup excludes it from the bundle...
export const square = x => x * x;
// This function gets included
// rewrite this as `square(x) * x`
// and see what happens!
export const cube = x => x * x * x;
// This "side effect" creates a global
// variable and will not be removed.
window.effect1 = 'created';
const includeEffect = false;
if (includeEffect) {
// On the other hand, this is never
// executed and thus removed.
window.effect1 = 'not created';
}
... bundle comes out
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