mstange/testcase-babel-windowbinding

A small repo that demonstrates how easy it is to move Object.getOwnPropertyNames(window) into your startup path

This is a testcase that uses a very basic webpack + babel setup to compile ES6 to ES5. It makes use of the transform-runtime babel plugin, with the helpers flag set to true.

With these settings, any use of the extends keyword will cause the initial evaluation of the JS to take at least 20ms in Firefox, because one of the transform-runtime helper modules calls Object.getOwnPropertyNames(window) during module initialization.

npm install
npm run build

This will run webpack + babel to compile index.js to bundle.js.

Loading index.html will print how long it took to require('./benchmark').